Research on Nanowires Helps Scientists Communicate Across the Fence

Ludovico.CademartiriA passion for the fundamental sciences and for things that grow motivate Ludovico Cademartiri, an assistant professor in materials science and engineering, as he develops methods for making new materials using polymers and crystals at Iowa State University.

In a recent study, Cademartiri led a team of scientists that researched the formation and properties of nanowires, which are strands of solid matter 50 thousand times thinner than the average human hair.

He explains that current research applies nanowires as fillers for composites and electrodes for batteries, electronic circuitry, such as radio transistors, and all applications where both high surface area and connectivity are required. He adds that the nanowires made in his study might find application in light detectors or thermoelectric devices.

However, Cademartiri said nanowires are still being developed for application in commercial products.

A new class of materials

The scientific journal Advanced Materials published a paper on this topic, entitled “Nanowires and Nanostructures that Grow like Polymer Molecules,” that Cademartiri wrote alongside his graduate student Santosh Shaw.

Cademartiri says the paper was designed and developed to help researchers understand how and why nanowires produced in his study form in a way akin to polymers. It also reviews existing research about polymer-like growth and behavior in crystals and nanostructures and proposes guidelines for creating “polymer-like” crystals and assemblies.

“We’re interested in the fundamental question of whether we can get crystals to behave like polymer molecules,” Cademartiri said.

In general, nanowires are made through a process that produces crystals, called crystallization. But the nanowires made in Cademartiri’s study formed in a process similar to polymerization, which makes polymer molecules.

He says this research also demonstrated that scientists could potentially create nanowires that possess polymer-like traits, such as flexibility.

He hopes the publication could also be the start of a dialogue between polymer and crystal scientists.

“We believe there are a lot of perceived differences between the crystals and polymers are often based on old and maybe unwarranted assumptions,” he said regarding polymers and crystals. “If these nanowires are really what they could be, they could serve as a means for scientists from traditionally separate fields to talk to each other in a more productive and creative fashion.

January 7, 2014 by Eric Debner

Robotic Weeding Leads to Big Labor Savings

Lie Tang (right) talks with Ken Blackledge about how his robot will be designed to aid organic farmers. Blackledge owns and operates Black Cat Acres in Nevada, Iowa, with his wife and children.
Lie Tang (right) talks with Ken Blackledge about how his robot will be designed to aid organic farmers. Blackledge owns and operates Black Cat Acres in Nevada, Iowa, with his wife and children.

Lie Tang’s research in field robotics offers a glimpse into the future of organic agriculture.

Tang, an associate professor in the Department of Agricultural and Biosystems Engineering, develops robotics technologies for intra-row weed removal in vegetable crops. He hopes that by perfecting this technology, he can design an automated robot to lower the level of labor and chemical inputs in small to mid-sized growing operations for farmers who are looking for environmentally friendly weeding alternatives.

Tang, a native of China, was drawn to Iowa State University in 2004 by the reputation of the agricultural and biosys­tems engineering department as being on the forefront of agricultural innovation. “This is one of the best places in the world for agricultural robotics and automation,” he says.

Robotic response

After talking with Iowa growers of small to mid-size vegetable plots, Tang recognized a hole in current weeding approaches that robotics could fill.

“Weeding has been a long-standing problem for many years because there is no silver bullet—there are just too many variables. And for organic farmers, their options are very limited. Their options are either chemical, laborious or expen­sive,” says Tang. “My robot design offers the producer a more effective and sustain­able alternative.”

For organic farmer Ken Blackledge, owner of Black Cat Acres in Nevada, Iowa, the battle with weeds occupies much of his time and energy.

“If a robot could weed a diverse crop planting and be cost effective I would be interested. Management of weeds is one of the biggest challenges I face. The costs involved take resources away from crop development, time needed to market and other more productive activities,” says Blackledge.

A key part of the small weeding robot is the sensing system used to distinguish produce from weed. Real-time vehicle location in reference to plants, rows and landscape will be monitored and adjusted based on two-dimensional and three-dimensional data.

“There are other, larger weeding robots on the market. But these are designed for much larger growing operations and require high accuracy GPS systems—few farmers in Iowa can buy that type of equipment,” says Tang. “The robot will take pictures with three-dimensional sensors to provide more robust information than a conven­tional camera.”

The time of flight of light data will be used to calculate distance, and give a picture of what types of plants are growing in the row. If a weed is found, the small actuators on the robot disturb the soil around the crop and within the row, removing any weeds mechanically without disturbing the crop. The small robot will be designed to travel over planting rows without disturbing the seeded crops, such as carrots, beans, lettuce, sweet corn and many other vegetable crops.

By getting as close as possible to the plants, the robot is able to autonomously remove weeds without the use of herbicides or plastic sheeting while increasing production.

Technology that transforms

Kathleen Delate, professor of horticulture and co-principal investigator, has been enthusiastic about the potential the project holds for organic farmers. She says that not only does the robot offer alternatives to herbicides, it also considers the importance of soil structure.

“Robotic technology for weeding offers promising options for all producers by decreasing labor to manage weeds but also potentially alleviating soil compaction that could occur with tillage. Organic producers especially are interested in this technology because herbicides are disallowed in organic production, and with the increasing problem of herbicide resistance, more and more producers will be looking for alternatives,” says Delate.

Tang’s research group and collaborators had originally manufactured a larger, slightly more cumbersome robot that served as inspiration for the new, smaller and more aesthetic design. “In this generation of robot, we are integrating sensing and controls together to fine tune the robot’s capabilities,” says Brian Steward, professor of agricultural and biosystems engineering and co-principal investigator. “This technology is potentially transforming.”

The future is now

As Steward explains, automation and sensors are developing rapidly. Precision agriculture technologies are quickly being adopted, and thus transforming the farming lifestyle and industry. In order for these technologies to run properly and be maintained, the next generation of agricultural engineer is being trained early to embrace robotics.

“My sons are participating in FIRST robotics competitions,” says Steward. “Students are learning to design robots as children. As they move forward in their education, it increases our society’s aptitude with robotics. If we are going to adopt robots in agriculture, we need people who can build and repair them. That’s happening now.”

As the project moves forward, Tang recognizes there will be obstacles, including economic feasibility. However, he’s proud of the attention his peers have given his work—this marks one of the first times agricultural field robotics has been included in an organic agriculture related grant.

Pioneering innovative and technologically advanced research has been a staple in the department since it’s inception in 1905. It is the birthplace of the first large round baler and whirlwind terrace plow. Over the years, scientists and professors in the department have served as leading investigators of farm mechanics, post harvest grain, farmstead structures and natural resources, proven by their many patents. A feat Tang is eager to replicate.

At this early stage of research and design, it’s hard to tell if Tang’s robot will find a place among other inventions to come out of the agricultural and biosystems engineering department. But with his team, passion and advancing robotics technology it’s not hard to imagine.

December 9, 2013 by Dana Woolley

Iowa State Researchers Setting Up “Dream Team” to Research, Develop Nanovaccines

Iowa State’s Michael Wannemuehler and Balaji Narasimhan, left to right in a lab at the College of Veterinary Medicine, are working to develop nanovaccines. Narasimhan is holding a small vial of a nanovaccine formulation for pneumonia. Photo by Amy Vinchattle.
Iowa State’s Michael Wannemuehler and Balaji Narasimhan, left to right in a lab at the College of Veterinary Medicine, are working to develop nanovaccines. Narasimhan is holding a small vial of a nanovaccine formulation for pneumonia. Photo by Amy Vinchattle.

Iowa State University researchers think developing nanovaccines using a “systems” approach can revolutionize the prevention and treatment of diseases.

Just think, since 1980 the world has seen more new diseases than medical science knew before 1980, said Balaji Narasimhan, Iowa State’s Vlasta Klima Balloun Professor of Chemical and Biological Engineering and leader of a new project designed to eventually establish a national nanovaccine research center.“This is scary,” he said. “The diseases we have vaccines for today are the low-hanging fruit. And so people get sick. But we can’t just keep treating these new and re-emerging diseases. That’s too expensive. We have to prevent them.”

Narasimhan thinks nanovaccines are the best arsenal for that fight. Nanovaccines, unlike current vaccines, are based on tiny particles that can send pathogen-like signals to immune cells. They can prevent disease. They can boost the immune system’s own response to disease. Production is quick. Storage is easy. And the technology is sustainable.

‘Dream team’

Narasimhan has assembled a team of university, medical school, research hospital, national laboratory and industry researchers to design nanovaccines targeting diseases such as tuberculosis, malaria, biodefense pathogens and cancer.

“This is truly one of the dream teams working on vaccine research anywhere in the world,” Narasimhan said.

The research team is being launched with support from a three-year, $4.5 million grant from Iowa State’s Presidential Initiative for Interdisciplinary Research. Iowa State President Steven Leath established the initiative to build research teams capable of competing for large research grants and making major discoveries.

The nanovaccine team and three others won the initiative’s major, pursuit-funding awards and another three teams won one-year, $100,000 proof-of-concept awards.

“These proposals are just what we wanted to see,” Leath said when he announced the awards last June. “They pull together talented researchers from our university, other institutions, national labs and industry to tackle some of the grand challenges facing our world.”

Narasimhan has used the award to recruit a team of 43 researchers from universities, companies, research institutes, national labs and a research hospital. The team includes 21 researchers from Iowa State in addition to researchers from the University of Iowa and three Ames-based entities, the National Animal Disease Center, NewLink Genetics Corp. and PK Biosciences Corp.

The project’s five research thrusts and their leaders are:

  • Thrust one, Novel design and production of antigens (substances that stimulate the production of antibodies), led by Susan Carpenter, an Iowa State professor of animal science;
  • Thrust two, Nanoscale adjuvants (agents that boost immune response) and delivery systems, Narasimhan;
  • Thrust three, Immunological mechanisms and vaccine efficacy, Michael Wannemuehler, professor and chair of veterinary microbiology and preventative medicine in Iowa State’s College of Veterinary Medicine;
  • Thrust four, Scale-up, current good manufacturing practices and clinical testing, Tom Dubensky of Aduro BioTech Inc. based in Berkeley, Calif.
  • Thrust five, Global deployability and economic analysis, Richard Silberglitt of the RAND Corp. based in Santa Monica, Calif.

Looking at the whole system

The team will take a “systems” approach to its research and development, Narasimhan said. That means engineers, doctors, biologists, chemists, materials scientists, industry researchers and social scientists will work together throughout the development of nanovaccines.

“When designing a vaccine, we need to think about where it will be deployed, who will use it and how much it will cost right from the onset,” he said. “Right now, that doesn’t happen.”

Narasimhan has worked more than a decade to develop nanotechnology for medical applications. Working with Wannemuehler of Iowa State’s College of Veterinary Medicine, Narasimhan and the staff and students in his lab are producing biodegradable polymer nanoparticles that mimic the size and chemistry of pathogens to trigger appropriate immune responses in the body.

Nanoparticles can also be loaded with medicines and used to slowly deliver drugs to fight off diseases, including brain ailments, lung problems and even cancer.

A bench-to-bedside approach

Narasimhan said the nanovaccine research team already has some successes to report:

The University of Nebraska Medical Center has won an $11 million grant from the National Institutes of Health to study nanomedicines, including a nanovaccine for cancer. And, the Bill & Melinda Gates Foundation awarded Iowa State researchers a $100,000 grant to study single-dose therapies for malaria and filarial diseases such as elephantiasis and river blindness. Success with the initial Gates grant would allow the researchers to apply for an additional grant of up to $1 million.

Narasimhan said the timing is right to win more support for the research team’s new approach to developing nanovaccines: Illnesses such as whooping cough are making a comeback. Bacteria are growing resistant to antibiotics. There are undesirable side effects to some common medicines. And some treatments are too expensive for the developing world.

“This integrated bench-to-bedside approach,” he said, “will translate exciting scientific discoveries to life-saving products.”

December 3, 2013 by Mike Krapfl

Creating Accountable Anonymity Online

Yong Guan
Yong Guan

Systems that allow users complete anonymity are being abused.  ECpE’s Yong Guan wants to add some accountability.

The World Wide Web is, in many ways, still the Wild West. Though a large portion of internet traffic is monitored and traceable, systems like the Tor Project allow users to post and share anything anonymously. Anonymous systems provide enormous public benefits by helping journalists, activists, and others communicate in private, away from the prying eyes of the Internet at-large.

These systems, however, have been degraded by criminals who use them to support unlawful activities. Tor reportedly has been used to aid in the selling of illegal drugs and in the proliferation of child pornography, among other crimes. With complete anonymity, criminals are often free to do whatever they like with little or no repercussions.

Researchers at Iowa State are working to solve this problem with an approach they call Accountable Anonymity. Yong Guan, associate professor, and his students, have devised a system that offers anonymity for honest users, and accountability for dishonest users.

“The lack of accountability on these anonymous services is easy to exploit,” Guan says. “Criminals use anonymous systems to commit crimes against innocent people online and in the real world. I thought there was a real need for accountability within these systems to protect honest users that just wish to exchange lawful information anonymously.”

Tor works by sending information through a series of nodes and using layers of encryption at each stop. When the information arrives at its destination, the encrypted messages are unlocked with a key and the original message becomes readable. The layers of encryption disguise the origin of the message, thus providing anonymity, but at a high computing cost. Bouncing messages around a network, and adding a layer of encryption with each bounce, takes time and computing power. If a criminal uses the service to send a malicious message, the network expends the same computing power to send that message, and the victim has limited ways in which to trace it.

Guan’s Accountable Anonymity system, named THEMIS, is designed to minimize the computing power used to send messages and provide a way to track the source of the message, should it be thought of as malicious. By its very design, the system, as a measure for both deterrence and retributivism, avoids expending computing power to send illegal and harmful messages.

“With a level of accountability, criminal activity online will decrease,” Guan says. “By that measurement, computing power expended to support criminal activity will also decrease. That’s a good thing.”

The Accountable Anonymity system aims to offer four features. First and foremost, the system must provide anonymity under normal circumstances. Users looking to exchange information in a lawful manner without being tracked will be able to do so without problems.

“Providing reliable anonymity is the first step,” Guan says. “Without it, users won’t use the system.”

Second, the system must, under certain circumstances, allow for the identification of sources without impairing other users’ anonymity. This involves a number of steps, including notifying law enforcement. This feature would be used to find senders of malicious messages, and requires the cooperation of the system’s key generator and internet service provider’s registration database.

“Our system provides law enforcement with the means to catch criminals who wish to distribute illegal or harmful messages,” Guan says. “Without some kind of accountability, users tend to show an absence of restraint.”

Third, the system must be incentive-compatible. This means users must have an incentive to use the system as it is intended to be used. Without incentive-compatibility, users can simply bypass attributes of the system they don’t wish to comply with.

Fourth, the system must make framing or impersonating an honest user impossible. THEMIS achieves this by using digital signatures that are computationally infeasible to generate without source keys.

“Forging keys is computationally difficult,” Guan says. “If a node wishes to obtain a signing key, or sign a message without the source’s signing key, it would have to solve a problem that is incredibly difficult, even for the fastest computers.”

THEMIS is comprised of two separate proxy re-encryption based schemes. Scheme one, a multi-hop proxy re-encryption-based scheme, provides an anonymous communication channel between the source of a message and its destination. Much like with Tor, messages in THEMIS are bounced through several proxies. However, instead of adding layers of encryption, THEMIS converts the original message at each stop using XAG encryption. Each proxy along the path knows only its predecessor and successor, and proxy re-encryption keys to corresponding channels are hidden in the message in an onion header. The layers of the onion header contain the information for the corresponding node.

Scheme two provides for accountability when malicious messages are present. As with any encryption system, public keys and private keys are utilized to ensure that messages arrive where they should and are readable to the intended recipient. However, an AFGH re-encryption key is included with each message and serves as the accountability information which links the destination of the message to its source. Without this AFGH re-encryption key, messages are unreadable.

At the request of the message recipient, law enforcement officials can use the AFGH re-encryption key to track the source of the message. Law enforcement can subpoena data from the key generator and the internet service provider’s registration database (both nodes along the path the message follows) and use this data with the message’s AFGH re-encryption key to determine the source of the message.
“If no one reports the message as malicious,” Guan says, “law enforcement cannot get involved. There would be no way for them to know about it.”

Guan envisions his system as a way for law enforcement to track down senders of threatening emails and those who leak important documents. THEMIS represents the first system to provide both anonymity and accountability in an incentive-compatible fashion and the first anonymous network to use multi-hop proxy re-encryption.

“The next step,” Guan says, “is to test it on a large scale over the internet. This way, we can really see how well it performs.”

November 7, 2013 by Brock Ascher

Iowa State, Ames Lab Engineers Develop Real-Time 3-D Teleconferencing Technology

Nik Karpinsky quickly tapped out a few computer commands until Zeus, in all his bearded and statuesque glory, appeared in the middle of a holographic glass panel mounted to an office desk.

The white statue stared back at Karpinsky. Then a hand appeared and turned the full-size head to the right and to the left. Yes, it was quite clear, Zeus really was pictured in 3-D.

Nik Karpinsky, left, and Song Zhang show off their 3-D teleconferencing technology.

And there it was from one computer work station on the second floor of Iowa State University’s Howe Hall to another down on the first floor: 3-D teleconferencing that’s live, real-time and streaming at 30 frames per second.

“Four years ago, this would not have been possible,” said Karpinsky, an Iowa State doctoral student in human computer interaction who’s been working day and night to make the technology a reality.

Part of the problem is the complexity of the technology, said Song Zhang, Iowa State’s William and Virginia Binger Assistant Professor of Mechanical Engineering, an associate of the U.S. Department of Energy’s Ames Laboratory and the leader of the 3-D imaging project.

“There are a lot of skills involved,” he said. “You have to do programming, optical engineering, hardware, software  and networking.”

To make it all work, Karpinsky and Zhang had to solve three big technical problems: capturing the 3-D images, transmitting the images and displaying the images.

“I was originally worried about transmission,” Karpinsky said. “But we had to focus on all three.”

The result of successfully combining those technologies is a proof-of-concept prototype that Karpinsky and Zhang call “Portal-s.”

It all starts with a projector that shines a light straight at a teleconferencer, in this case, that bust of Zeus. There’s a camera to the right of the projector and one to the left, both angled toward the subject. The cameras record two images of the light as it’s distorted by the subject. The images are combined to create a single 3-D image.

That optical hardware is networked and connected to a standard computer with a graphics card. The computer combines, processes and compresses the images. (And it really compresses them – from 700 megabits per second to less than 14 megabits per second.)

The compression allows transmission of 3-D images to another computer, even over wireless networks.

The idea, Karpinsky said, is for the projectors to become the eyes of the teleconferencing system: “What the projector sees is what you see.”

Karpinsky and Zhang see a bright future for the technology they’ve developed with the help of support from the National Science Foundation and Iowa State’s Virtual Reality Applications Center.

Zhang said the next steps include developing and testing applications for smart phones. He thinks the technology is only a few years away.

“In the future, we can do all of this 3-D video conferencing on the phone,” he said. “These phones are powerful enough to do all the computation.”

Zhang also wants to develop the 3-D teleconferencing technology for use in powerful virtual reality environments such as Iowa State’s C6, a six-sided room that surrounds users with 100 million pixels of 3-D images.

(Karpinsky won’t be part of the continuing research and development work at Iowa State. He graduates this semester and will move to Washington state to work for Microsoft. He’ll also work for a startup imaging company called Phasica3D that spun out of Iowa State research.)

All of these 3-D developments, Zhang said, are coming far faster than he expected.

“When Nik first proposed this idea to me,” he said, “I never believed we could reach this level by now.”

October 31, 2013 by Mike Krapfl

Harnessing the Science of Light for Biosensing

It started as a passing fascination with an insect. Andrew Hillier, chair and Wilkinson Professor of Interdisciplinary Engineering of the Department of Chemical and Biological Engineering at Iowa State University, observed a brilliant purple-blue wasp on his driveway at home and wondered at its intense color.

“This insect, called a steel blue cricket hunter, is pretty—with an intense, iridescent purple-blue shell. But that color isn’t due to pigment. It’s due to the structure on the surface of the insect’s body,” Hillier explains.

This phenomenon is not unique to the wasp; many insects and birds display similar coloration with the same science behind it.

In the case of the wasp and other insects like it, it displays what is known as structural color. This color can arise from an exoskeleton that is composed of a periodic surface pattern that interacts with light. When light hits the surface of the exoskeleton certain wavelengths are absorbed and others scatter.

“In some cases, the surface consists of a series of exceedingly thin layers, which create constructive and destructive interference, and the color that you see is the result of that particular combination of nanoscale layers,” explains Hillier.

The science of light has intrigued Hillier for years. And it’s why his research group at Iowa State has been working since 2006 to harness the science of that structural color into tools for biosensing, a technology that converts a biological response into a measurable signal, such as a color change, in order to detect the presence of a particular analyte.

Recently awarded a $450,000 grant from the National Science Foundation, Hillier is  conducting ongoing research to imitate these nanostructures found in nature. But he’s doing it in a slightly different way.

Hillier is creating nanostructures across a surface rather than down into it, and combining these layers with a metal film. The combination, when exposed to light, excites an oscillation of electrons along the surface called a surface plasmon.

“Depending on how we arrange the surface and how we hit it with light, we can create a structure that produces a very specific color. For example, we can make a surface that appears red and becomes a deeper red when something absorbs onto it. The nanoscale control allows you to define the color, where it is in the visible spectrum and to a degree how intense it is. You can even make multiple colors on a single surface using more complex surface structures. So these devices are beautiful as well as full of information.”

The surface can then be constructed to detect a specific protein, DNA molecule, pathogen or pollutant.

“In some ways, these surfaces function like a traditional piece pH paper, where a simple dip into solution produces a color change, but in this case you can be highly specific and sensitive,” says Hillier. These biosensors have a wide range of potential uses in medicine, public health, environmental monitoring, food safety, defense, and forensics.

His group started the research experimenting with a nanostructured surface that most people have lying around their house—a compact disc.

“These disks are made of polycarbonate plastic, with grooves stamp-melted into them at a spacing of about 1.5 micrometers. It’s what gives them their rainbow-colored appearance and what helps a laser track its position on the disc. Coincidentally, it’s also a really convenient spacing for exciting a surface plasmon,” says Hillier.

Hillier’s research team has also used DVD and Blu-Ray discs to inexpensively experiment with before developing their own manufacturing techniques for creating metal-coated sensor chips with nanostructures that are precisely tuned to create a desired signal.

“It’s a very simple visual cue to see a color change, but in a quantitative sense it’s also a really significant and an easily measurable signal,” says Hillier.  “You can use a spectrometer, a CCD camera, a photodetector, or even your own eye. There are all kinds of options that can be small, miniaturized, highly sensitive, portable, and even parallelized, so you could have arrays of different sensors to detect a number of different analytes on the same instrument.”

Hillier’s most recent work looks at taking the sensing capabilities of the chips even further, combining the quantitative information available from surface plasmon resonance sensing methods with a more traditional analytical technologies, such as infrared spectroscopy.

“The problem with infrared is that it will tell you what, but not how much,” said Hillier. “We’re exploring the possibility of combining the two spectroscopies into a new type of instrument where we can measure chemistry with infrared and quantity with the surface plasmon.”

Hillier’s research has also yielded a number of theoretical models that can accurately predict the behavior of these biosensors. The models allow Hillier’s research group to computationally design a biosensor and calculate how light will interact with its structure.

September 5, 2013 by Laura Millsaps

Developing New Batteries for Space Exploration

Batteries have become such a modern day convenience that many times we don’t think about them until they need recharged or replaced. Even in space, batteries make life easier by advancing exploration when they are used in land rovers, astronaut equipment and energy storage devices.

But creating a battery for space exploration requires some interesting considerations, according to Steve W. Martin, Anson Marston Distinguished Professor in Engineering in the Department of Materials Science and Engineering.

He’s working with Scott Beckman, assistant professor of MSE, on a project to create lithium-sulfur batteries that will support the next generation of human space exploration.

“The best batteries have high voltages and high capacities,” Martin explains. “But when dealing with space exploration, you also need to factor in weight, cost and safety in an environment with no oxygen.”

Lithium-sulfur batteries would accommodate most of those requirements—they are solid, lightweight, and have good voltage, capacity, and energy density.

But sulfur is not perfect. It is an electron insulator instead of being an electron conductor. And it needs to be a lithium-ion conductor as well. So the research group is changing properties and making new atomic structures to improve the potential of the chemical element.

The project is supported by a three-year grant from NASA EPSCoR, a program that provides seed funding to develop academic research enterprises directed toward long-term, self-sustaining, nationally-competitive capabilities in aerospace and aerospace-related research.

Martin and Beckman’s team is working from both theoretical and experimental perspectives while also collaborating with three NASA research facilities in addition to colleges in Iowa.

“From a theoretical view, if we can validate our work with an experiment we can have great confidence in our ideas,” Beckman says. “It’s a great relationship that we are seeing more of in the field, and this project will be able to move at such a quick pace because of it.”

Assembling the right materials

The group has already begun developing battery materials in support of the project and will eventually create all three components of a battery—the anode, cathode, and electrolyte.

While the researchers will be designing an anode (the part of a battery that discharges energy) specifically for this project, they are focusing their attention on a composite sulfur cathode. The cathode will be coated in a dual lithium-ion and electron conducting glass ceramic.

“The end design will be like a skyscraper. The sulfur is stuffed in rooms, and the walls are electron and lithium ion conductors,” Martin explains. “The rooms will only accommodate a small amount of sulfur so the electrons and lithium-ions don’t have to travel far and can be delivered at a high rate.”

This hierarchical structure will also seal sulfur in the cells, keeping it “electrochemically active and accessible” while preventing it from escaping and dissolving.

In addition, the team is studying and preparing solid, conductive electrolytes to separate the anode and the cathode.

Beckman says a recently discovered material will allow the lithium to move quickly between the anode and cathode. Since this movement determines the power of the battery and the overall number of times it can be reversibly charged and discharged, the team is hoping the material can help them build a better battery.

“We want to find out why this material operates the way it does,” Beckman adds. “Then, we will be able to take those findings and create new materials or a new arrangement based on these structures to tailor and eventually improve the battery’s properties.”

Simultaneous work

While Martin and his graduate students are busy working on creating the battery components in large glove boxes located in a Hoover Hall lab, Beckman is looking at the atomic scale of materials to determine how atoms interact and bond, finding out what those qualities mean for the material system as a whole.

“The beauty of the collaboration is that you come at the problem from two different directions,” Beckman says. “After we make our atomic level models, we can have the experimentalists validate our ideas. They provide a real benchmark of our work.”

He adds that once the model and the experiments connect, even if it is in just one or two places, it provides confidence that they have a good theoretical representation of the system. “From this, we can expand our exploration where there isn’t a direct comparison with experiment,” he says. “This can not only provide guidance for future experiments, but it also allows for an underlying understanding of the way a system works.”

For example, when Martin comes across something interesting about a property like the thermal conductivity or ionic conductivity in the material, he can take it to Beckman for further modeling.

“It’s all about making connections—the experimentalists see something interesting happen, and then we tell them why it happened. They can use those ideas as they make up the next sample and so on,” Beckman says.

Additionally, researchers at NASA Glenn Research Center in Ohio are starting some support research of lithium-sulfur batteries. The parallel work will help the group make discoveries and ideas that much quicker.

Once the battery materials are fully developed, the team will send individual components and fully assembled batteries to NASA Glenn for testing. The Johnson Space Center in Texas will address battery safety.

“There is so little oxygen in space that if you have a battery fire consuming the oxygen it can get disastrous in a hurry,” Martin explains. “That’s why safety is such a critical part of this project.”

Finally, NASA’s Jet Propulsion Laboratory will help create the battery components. Martin and his students will visit the lab in California to learn techniques and specific measurements.

All of this work will happen in parallel over the three years with each group helping the other.

Establishing a battery program in Iowa

Beyond helping advance space exploration with batteries that could allow for longer astronaut and land rover missions, this project means Iowa State is gaining research competency and capacity.

And it’s something Martin hopes to use as momentum to build a battery program on campus.

“We are using this project as a foundation to write proposals for other projects, such as sodium battery research that could impact wind turbine energy storage,” he says. “That’s the great thing about the EPSCoR program—it’s about giving us a vehicle to do more.”

Martin adds that this project is particularly exciting because he has been studying batteries in one form or another for more than 30 years.

“It’s great to see the potential of this work and what it could mean for researchers on campus and for the state.”

August 29, 2013 by Jessi Strawn

Iowa State Turns on ‘Cyence,’ the Most Powerful Computer Ever on Campus

The most powerful computer ever on the Iowa State University campus – a machine dubbed “Cyence” that’s capable of 183.043 trillion calculations per second with total memory of 38.4 trillion bytes – is just beginning to produce data for 17 research projects.

The thinking and infrastructure behind the new machine will have much broader effects across the university.

“The whole campus is excited about this and so am I,” said Arun Somani, an Anson Marston Distinguished Professor in electrical and computer engineering and associate dean for research in the College of Engineering. “We expect to expand our science research with the help of high performance computing. We also expect this will expand Iowa State research. If you don’t have a machine powerful enough to do the calculations, you can’t even propose a project.”

Cyence, with its 12 black cabinets and rows of blue lights, is front and center in the Machine Room in the basement of the Durham Center. It has been running since early July. It succeeds Cystorm and its 28.16 trillion calculations per second as the most powerful computer on campus.

It was purchased with the help of a three-year, $1.8 million major research instrumentation grant from the National Science Foundation. Another $800,000 is being provided by Iowa State’s Office of the Vice President for Research and Economic Development and the colleges of agricultural and life sciences, engineering and liberal arts and sciences.

Somani led the faculty team that applied for the National Science Foundation grant. Other team members include Rodney Fox, Anson Marston Distinguished Professor in chemical and biological engineering and affiliate of the U.S. Department of Energy’s Ames Laboratory; Mark Gordon, Distinguished Professor in chemistry and affiliate of the Ames Laboratory; Gene Takle, professor of agronomy and geological and atmospheric sciences; and Srinivas Aluru, formerly an Iowa State professor of electrical and computer engineering now at Georgia Tech in Atlanta.

The team proposed that Cyence be used to support 17 research projects from eight Iowa State departments, including work in bioscience, chemistry, ecology, fluid dynamics, atmospheric science, materials science and energy systems.

Somani, for example, will use the new computer to help develop new and better infrastructure designs for the country’s energy and transportation systems.

“This computer enables us to solve larger models covering longer time frames,” Somani said. “We can do a lot more. This will help us a lot.”

August 21, 2013 by Mike Krapfl

Iowa State Engineers Develop New Tests to Cool Turbine Blades, Improve Engines

Engineers know that gas turbine engines for aircraft and power plants are more efficient and burn less fuel when they run at temperatures high enough to melt metal. But how to raise temperatures and efficiencies without damaging engine parts and pieces?

Iowa State University’s Hui Hu and Blake Johnson, working away in a tight corner behind the university’s big wind tunnel, are developing new technologies to accurately test and improve engine cooling strategies. Their current focus is to improve the turbine blades spun by the engine’s exhaust. Those blades at the back of the engine drive front blades that force compressed air into the combustion chamber.

“Right now, the current state of the art for engine combustion is about 3,000 degrees Fahrenheit,” said Hu, an Iowa State professor of aerospace engineering. “That temperature is above the melting temperature of all engine materials. If you don’t have cooling technologies, all the material will melt.”

One technology is to build hollow turbine blades and blow coolant through an arrangement of holes in the blades. The holes create a cooling film between the hot exhaust gases and the turbine blades, allowing the blades to keep their shape and strength.

But now, as manufacturers experiment with biofuels and efficiency improvements, Hu said combustion temperatures are heading higher and higher. And so it’s getting more and more important for engineers to research and develop heat-resistant materials and cooling technologies. Better cooling can mean fuel savings, longer-lasting parts and significant cuts in operating costs.

For the past 19 months, Hu and Johnson, an Iowa State post-doctoral research associate in aerospace engineering, have been working with the GE Global Research Center in Niskayuna, N.Y., to study turbine blade cooling.

Rather than trying to replicate the high temperatures inside a jet engine, the engineers have developed new technologies and room-temperature tests to study the effectiveness of cooling hole shapes, arrangements and the cooling film they create over a turbine blade.

They’ve built an experimental rig that places a model turbine blade at the bottom of a wind tunnel’s test section. Jets of pure nitrogen or carbon dioxide are blown through the model blade’s cooling holes. The main stream of the wind tunnel blows oxygen-rich air above the test blade. Using oxygen-sensitive paint on the model blade, an ultraviolet light source and a digital camera, Hu and Johnson can see if the cooling film keeps oxygen molecules from the main stream off the model blade.

“If we find an oxygen molecule on the model blade, we know that the cooling stream didn’t create a barrier,” Hu said.

So far, the Iowa State engineers have been working with low-speed flows. They’re now building and testing another experimental rig that can handle high-speed flows approaching the speed of sound.

They’ve also been using an advanced flow diagnostic technique called particle image velocimetry – seeding the test flows with tiny particles that can be photographed with a laser and camera – to record and measure what happens when gases blow out of the cooling holes.

Those tests provide data about flow structure, thickness of the cooling film, density ratios, velocity ratios and other measurements related to cooling effectiveness.

“The big goal of this study is to find anything that GE can do to improve the function of its film cooling system,” Johnson said. “Better cooling equals longer-lasting blades. And that could be worth billions of dollars across a fleet of engines.”

August 1, 2013 by Mike Krapfl

Iowa State Photobioreactor Research Could Speed Biofuels Development

Vigel and Olsen
Dennis Vigel (left) and Michael Olsen

Photobioreactors, the production systems used to grow algae, seem to operate on a simple concept: place photosynthetic microorganisms in a liquid growth medium and add light.

But Dennis Vigil, associate professor of chemical and biological engineering at Iowa State, and his research partner, Michael Olsen, professor of mechanical engineering, know that photobioreactors are much more complex systems than they seem. These researchers seek a better understanding of photobioreactors, which may prove beneficial in the race to find alternative fuels.

A better way to biofuels

Vigil and Olsen are part of a larger scientific effort to find alternatives to fossil fuels, which includes methods to produce biofuel from cultivated algae. In turn, researchers worldwide have designed a variety of photobioreactor systems to grow algae over the past thirty years.

However, economically viable commercial-scale methods to convert solar energy into biofuel via algae remain elusive.

To that end, Vigil and Olsen are leading a $350,000, three-year National Science Foundation project to understand the best way to design and optimize highly efficient photobioreactors.

“The technical and economic feasibility of large-scale production of biofuels from algae is going to require two major advancements,” said Vigil. “One is the bioengineering of elite microorganisms, and the other –my area of research– is improved design of the process equipment including photobioreactors.”

Finding an accurate model

Vigil’s and Olsen’s research project proposes to construct reliable computational models that can accurately describe the physical behavior of photobioreactor systems, which in turn can be used in the design of more productive, efficient systems.  To validate the computational models, the team will be conducting fluid dynamics and light transport experiments.

The first challenge of the research is to accurately describe the multi-phase flow occurring in a photobioreactor.

“You have a liquid growth medium circulating through the system,” explained Olsen. “In addition to the turbulent fluid flow, you have gas bubbles that are reacting to the turbulence and causing their own turbulence. And then there are the microorganisms as well.”

The second complexity, Vigil explained, is the transmission, scattering, and absorption of light as it goes through the algae suspension.

“Not all light is equally effective,” he said. “For photosynthesis, algae need certain wavelengths of light. We are learning that photobioreactor designs that were thought to receive plenty of light may be getting too much of the wrong wavelengths for optimal algae production.”

Measuring flow and light

The team will use lasers and high-speed cameras to track the positions of tiny “seed” particles in the flow of the bioreactor, a method called particle image velocimetry.

“Think of the particles as dust in the wind. We can capture images of the particle at a certain location, and then at a later time at a different location. We do a statistical dot-to-dot to tell us exactly how they behaved in the flow,” said Olsen.

Measuring light penetration into the reactor will allow the researchers to develop spectral models that describe varying amounts of different wavelengths of light, something Vigil said is a novel approach.

Vigil and Olsen said the pairing of the computation fluid dynamics and the radiation model will provide powerful insight into the way photobioreactors work because it allows for precise predictions concerning the light exposure experienced by algal cells.

“We can see an algae cell as it goes around in the reactor and observe what sort of radiation it is receiving. We can better understand why it is producing at a certain rate. These are the kind of deep, quantitatively accurate details that can be used to predict how much algae different reactor designs are likely to produce, and how they’ll perform,” Vigil explains.

A better design

Their insight is already giving Vigil and Olsen some ideas about tailoring reactor design. From previous research, Vigil noted that the optimal amount of light exposure algae need in relation to its entire photosynthesis process may be short, and that the random light exposure caused by bubble-induced mixing in most photobioreactor designs is not ideal.

“Essentially, if you want to speed up photosynthesis and use light more efficiently, the best thing possible is to have the microorganism capture photons, and then move it to a dark region of the reactor where the slow thermochemical reactions can proceed,” said Vigil.

That led Vigil to develop a bioreactor design using Taylor vortices, which occur when fluid is contained in between two rotating cylinders.

“Organizing the fluid flow creates a sort of conveyor belt system,” said Olsen. “It shuttles the organisms from light to dark in a much more orderly way.”

Ultimately, the goal of computational models is streamlining development of production systems, such as photobioreactors.

“We want to simplify this problem as much as we can with models that are fast enough and accurate enough so that engineers can use it in the design process,” said Olsen.

June 28, 2013 by Laura Millsaps

Changing the way engineering feels: A project to improve the accessibility of STEM fields for the visually impaired

Matthew Darden, Ph.D. student, uses a device called a three-axis dynamometer. It is used to measure the pressure and frictional forces of fingertips sliding against various materials and textures.

Open an engineering textbook, and you’re sure to find charts, graphs, and complex equations. Hard enough to decipher, imagine parsing that information if you were blind or visually impaired.

Conveying the detailed visual information that goes hand-in-hand with disciplines in the science, technology, engineering, and mathematics (STEM) fields isn’t necessarily impossible. But, according to Cris Schwartz, associate professor of mechanical engineering, it’s not something that happens as often as it should.

“Many students with visual impairments are extremely talented. There is no reason they shouldn’t be able to go into STEM fields, but there just aren’t a lot of educational tools for them,” he explained. “Even at the professional level, if they got a degree in chemistry or engineering, how would they actually do their job in the real world?”

That’s why Schwartz is using his National Science Foundation CAREER Award to look for ways to make the fields more accessible to those with visual impairments.

“What becomes immediately apparent when working with these students is that the tools they have in terms of sketching out ideas, working in groups, or interpreting visual information are very crude—think World War II era in a world completely saturated in display technology,” Schwartz said.

In his proposal “Using haptically augmented tactile communication methods to foster the inclusion of the visually impaired in science, technology, engineering and mathematics (STEM) professions,” Schwartz plans to look at a theoretical maximum in terms of how much information can be packed into a given surface area when using tactile communication methods.

“We want to see if it’s possible to use existing braille and do things in addition to the raised dots, like change the friction, prickliness, temperature, etc.,” he explains. “Is there anything we can do to add more information in that same space so students can get more information from their textbooks even if they are coded in braille?”

From there, he wants to use any lessons learned to develop some new methods and techniques for illustrating information in ways that aren’t currently being used.

Schwartz is building on some of his previous work in biotribology, which looks at friction as it relates to objects that come into contact with the human body. While working in the field, he and fellow researchers started to realize the importance of tactility and touch, and that despite the psychological component involved, there are fundamental engineering questions to be answered—like what manufacturing processes are necessary to make a surface feel a certain way.

Mark Placette, Ph.D. student, uses finite element modeling to better understand the friction and heat generation in systems where polymers come into sliding contact with metals.

That’s when he started thinking about how surfaces are associated with different tactile characteristics. “You can get human evaluators to explain what they feel when they touch a surface, and then you can convert that information into mathematical, quantitative terms,” he said. “If we can start correlating the sensory information with measureable surface properties and textures, we can start designing surfaces that exhibit desired tactile attributes.”

In addition to his research, Schwartz has been working with the Texas School for Blind and Visually Impaired in Austin for a few years. He developed and taught a one-week summer course called ProblemBusters! to teach visually impaired and blind students about engineering design, thermodynamics, and mechanics in an immersive environment. Similarly, he has recently started a partnership with the Iowa Braille School in Vinton, working to incorporate realistic engineering experiences into activities for some of the state’s visually impaired students.

Both of those projects will continue as part of this CAREER award, as well as the possibility of developing a collaborative design website. The site would allow students at these schools to give ideas to engineering students to co-develop a product the visually impaired community needs.

Schwartz says solving these sorts of problems is what makes this an important engineering project, even though it has so many other interdisciplinary components.

“What motivates me is that once we import what we already know about how the world works and how to display information into some sort of tactile-based system, we may really start seeing the untapped potential of students with visual impairment,” he said. “My hope is that when these students enter the STEM fields, they will start being the innovators, giving personal insight into how to make these display technologies and approaches even better, so essentially the problem will be solved in the long term.”

May 23, 2013 by Jessi Strawn

Iowa State Professor to Use Car Brake Technology to Protect Building Structures

Dr. Laflamme’s proposed semi-active damping system works much like car brake technology.

Civil, construction and environmental engineering Assistant Professor Simon Laflamme will use car brake technology to ensure the structural integrity of buildings. Thanks to a recent $200,691 National Science Foundation (NSF) grant, Laflamme will integrate electronic control systems to reduce building movements due to wind and earthquake hazards.

His project is entitled “Developing the Next Generation of Cost-Effective High Performance Damping Systems for Seismic and Wind Hazards Mitigation.” The goal is to advance the technology of systems to reduce building damage during earthquakes, and ensure building serviceability during moderate and strong wind events.

For example, when winds blow against a building, the damping system detects building motion, triggering electrical signals to drum brakes installed in building floors to dampen movement in the building’s structure. Adding electrical signals is what transforms passive technology, like viscous dampers, into semi-active damping systems, allowing a substantially greater mitigation performance. “Much like drum brakes enable cars to decelerate, this semi-active damping system dissipates energy in movement through friction,” Laflamme says.

The semi-active damping technology would run on a building’s electrical power. And in case of a power outage, a battery would provide high, robust and reliable damping.

April 5, 2013 by Chris Neary

Developing Polymer Drugs for Cancer Treatment

Through research on drug delivery systems, Kaitlin Bratlie, assistant professor of materials science and engineering and chemical and biological engineering at Iowa State, is working on a way to treat cancers that don’t respond well to current treatments.

Her project has been underway for just a year and is several years away from clinical trials, but she says it’s the potential that keeps her motivated.

“These developments could actually turn around the prognosis of some cancer patients,” she explains.

Bratlie’s project is targeting tumor-associated macrophages, which are cells found in certain cancers and enhance the progression of tumors by creating blood vessels. She is looking to reprogram these macrophages to act instead like pro-inflammatory macrophages that prevent cancerous cells from becoming tumors.

Assisted by a team of four graduate and seven undergraduate students, she is currently developing a delivery vehicle for the drugs used to treat patients. Bratlie says other researchers have explored biodegradable polymers, but her research uses a polymer to encapsulate the medicine.

Through a grant from the National Science Foundation, Bratlie’s team is looking at a variety of chemical characteristic groups to determine their reactions with the polymer that would be used in delivering cancer-fighting medication. They want to uncover a functional group that will alter macrophage secretion profiles into pro-inflammatory macrophages

Once they have the correct functional group, the researchers plan to chemically modify a hydrogel that can encapsulate a drug within the polymer. The drug will be tested in animals, and they will look for apoptosis, or cell death, to ensure the treatment kills the cancerous cells.

Like most new developments in the world of science, Bratlie’s work with drug delivery mechanisms stems from a gap in knowledge. In this case, the gap pertains to cell responses to biomaterials. Her knowledge relating to drug release came from her post-doctoral work, which, in part, involved using biodegradable polymers to do a controlled release of corticosteroids to reduce the foreign body response to transplanted artificial organs.

“I identified a gap in the literature, and then happened to be using the drug delivery devices themselves to reprogram these macrophages,” says Bratlie. “And that’s why we’re going down this road.”

Bratlie says success with this project could offer cancer patients being treated unsuccessfully with current drug therapies a different outcome. “It would change people who have poor prognoses to actually being cured of cancer,” she adds.

March 4, 2013 by Eleni Upha

Iowa State’s MIRAGE lab mixes real and virtual to create new research opportunities

ZX6GTwo armed soldiers stand behind a barrier, guarding a checkpoint in the road, watching for trouble.A white truck turns toward them.“See what he wants, guys,” says one of the guards.“Sir, we have a military-aged male jumping out of the truck. He’s going behind that van.”

“Is he armed?”

“No visuals, sir.”

And so goes another training session in MIRAGE, an Iowa State University lab that mixes elements from virtual and real worlds to create unique training and research opportunities.  MIRAGE (Mixed Reality Adaptive Generalizable Environment) has been used by researchers since 2010. It’s part of Iowa State’s Virtual Reality Applications Center (VRAC).

The MIRAGE research team is led by Stephen Gilbert, associate director of VRAC and assistant professor ofindustrial and manufacturing systems engineering; Eliot Winer, associate director of VRAC and associate professor of mechanical engineering; and James Oliver, director of VRAC and University Professor of mechanical engineering. All three are also faculty in the human computer interaction graduate program.

The MIRAGE lab’s original project was a study for the U.S. Army Research Laboratory called “Veldt.” Gilbert said the project was designed to test whether military training that mixes physical and virtual objects could be more flexible and effective than, say, building a training facility that resembles a few city blocks of Afghanistan.

“We built MIRAGE as an ideal research lab for mixed reality,” Gilbert said. “It balances the real world with the technology we use in virtual reality.”

The lab’s technology includes:

  • a 33-foot by 11-foot screen with six projectors capable of producing 3-D images
  • 50-inch television screens that show 3-D images throughout the lab
  • 24 infrared optical tracking devices mounted in the ceiling
  • a surround-sound audio system
  • a control center loaded with computing power, graphics card technology and the capability of connecting with other virtual reality labs
  • walls, barriers and other props that can be moved around to create rooms, buildings, alleys or even a war zone checkpoint

“In this lab, we’re very good at integrating hardware from multiple systems and multiple vendors and tying it all together in novel ways,” Winer said.

In the checkpoint scenario, for example, armed guards are stationed behind barriers. The projectors show images of a road with parked cars and moving traffic. And then there’s the unidentified military-aged man jumping out of his truck and hiding behind a van.

The guards crouch behind their barrier and aim their rifles in case there’s trouble.

“It’s engaging your whole body,” Gilbert said. “It’s much more visceral.”

All movements by the soldiers-in-training – even virtual bullets from the fake rifles – are tracked to within a millimeter.

“Now we can go back and collect all this data and say, ‘The reason you made that mistake and got ‘killed’ that time was because you were looking in the wrong direction when this happened,” Oliver said in a video about the Veldt project. “We have a wealth of information we can mine to tune those training scenarios specifically to help.”

While it was originally built to study military training, MIRAGE can also help researchers with many different projects.

Gilbert is working with other researchers who are considering the MIRAGE lab for studies of violence mediation, promotion of physical fitness and the training of emergency responders. The lab has even been home to VRAC’s annual Halloween haunted house organized by students.

Gilbert said part of the lab’s effectiveness is the ability to use props and technology to create all kinds of environments. In many ways, it’s the same kind of stagecraft that goes into creating a play or movie.

“This lab,” he said, “gives you the immersive experience of the real world but the flexibility of a video game.”

“Sensing Skin” for Turbines Could Reduce the Cost of Wind Energy

A project that started out as a side experiment to monitor bridge damages has since evolved into a revolutionary, cost-saving solution in the world of wind energy.Simon Laflamme, assistant professor of civil, construction, and environmental engineering at Iowa State, began developing a damage-detecting polymer “skin” as a student at MIT.The skin, which is made into about 3-inch square pieces, consists of an inexpensive polymer material sandwiched between a painted polymer mixed with carbon black to make it conductive, which allows it to send signals to computers monitoring for any distortions.Once the skin is applied to a surface, it acts as a sensor that detects small cracks as it stretches. Its capacitance, or stored electrical charge, is measured as it changes.Originally planning to use the skin for bridges because of his background in civil engineering, Laflamme traded bridges for wind turbines when he was hired by Iowa State in 2011.

He says this shift was partly due to a lack of long-term data on the potential return on investment from monitoring the solutions when applied to bridges. With wind energy, however, researchers can determine how much money a sensing skin could save over the next 20 years.

And, he adds, the research is promising. “With wind turbines as a good application for our technology, we started some more in-depth research on the skin to find out how it behaves, its applications, and optimization,” he says. “The idea was developed before I joined Iowa State, but now our understanding and research is really taking off with the wind industry.”

Because of the damage that occurs after years of fatigue from the load of the wind, turbine blades could greatly benefit from Laflamme’s sensing skin. The blades are hollow and composed of many sheets of materials glued together that can peel and crack over time—that’s where the sensing skin comes into play.

Like biological skin, the polymer material acts like a nervous system, sensing cracks in specific areas of the turbine blade like nerves would find a cut on a finger. Once damage is detected in real time, engineers can determine whether it needs to be fixed immediately or at all, which costs less than replacing a whole blade when it is beyond repair.

After the skin is applied and damage can be detected as it occurs, a pattern can be made to assess deterioration throughout the lifetime of a turbine. “The hope is to be able to do what we call a condition assessment—to be able to predict the future of the blade,” Laflamme says. “This way, engineers could look at how the blade behaves in the past to be able to predict the probabilities of failure and damage and to optimize maintenance operation on the blade.”

Laflamme identified maintenance as a big cost issue of wind turbines. His goal is to save money in the industry by improving the maintenance schedule, which would extend the life of a typical turbine beyond the average 20 years. He says this would, in effect, reduce the cost of wind energy production.

Applying his research to turbines has allowed Laflamme to span multiple fields of engineering. The skin itself is produced in collaboration with the materials science and engineering department, but it also has ties with electrical and computer engineering for designing cost-effective data acquisition systems, and various efforts have been undertaken with aerospace engineering, the Center for Nondestructive Evaluation, and the Bridge Engineering Center at InTrans.

Laflamme says the fact that this research has a multi-disciplinary approach is a great added benefit. “This is the future of engineering—especially civil engineering—to get all fields together and create solutions for our problems,” he adds.

Iowa State Engineer looks to Dragonflies, Bats for Flight Lessons

VGKFEver since the Wright brothers, engineers have been working to develop bigger and better flying machines that maximize lift while minimizing drag.There has always been a need to efficiently carry more people and more cargo. And so the science and engineering of getting large aircraft off the ground is very well understood.But what about flight at a small scale? Say the scale of a dragonfly, a bird or a bat?Hui Hu, an Iowa State University associate professor of aerospace engineering, said there hasn’t been a need to understand the airflow, the eddies and the spinning vortices created by flapping wings and so there haven’t been many engineering studies of small-scale flight. But that’s changing.The U.S. Air Force, for example, is interested in insect-sized nano-air vehicles or bird-sized micro-air vehicles. The vehicles could fly microphones, cameras, sensors, transmitters and even tiny weapons right through a terrorist’s doorway.So how do you design a little flier that’s fast and agile as a house fly?Hu says a good place to start is nature itself.And so for a few years he’s been using wind tunnel tests and imaging technologies to learn why dragonflies and bats are such effective fliers. How, for example, do flapping frequency, flight speed and wing angle affect the lift and thrust of a flapping wing?Hu’s studies of bio-inspired aerodynamic designs began in 2008 when he spent the summer on a faculty fellowship at the Air Force Research Laboratory at Eglin Air Force Base in Florida. Over the years he’s published papers describing aerodynamic performance of different kinds of flapping wings.A study based on the dragonfly, for example, found the uneven, sawtooth surface of the insect’s wing performed better than a smooth airfoil in the slow-speed, high-drag conditions of small-scale flight. Using particle image velocimetry – an imaging technique that uses lasers and cameras to measure and record flows – Hu found the corrugated wing created tiny air cushions that kept oncoming airflow attached to the wing’s surface. That stable airflow helped boost performance in the challenging flight conditions. By describing the underlying physics of dragonfly flight, Hu and Jeffery Murphy, a former Iowa State graduate student, won a 2009 Best Paper Award in applied aerodynamics from the American Institute of Aeronautics and Astronautics.Another study of bat-like wings found the built-in flexibility of membrane-covered wings helped decrease drag and improve flight performance.And what about building tiny flying machines that use flapping wings? Can engineers come up with a reliable way to make that work?Hu has been looking into that, too.He’s using piezoelectrics, materials that bend when subjected to an electric current, to create flapping movements. That way flapping depends on feeding current to a material, rather than relying on a motor, gears and other moving parts.Hu has also used his wind tunnel and imaging tests to study how pairs of flapping wings work together – just like they do on a dragonfly. He learned wings flapping out of sync (one wing up while the second is down) created more thrust. And tandem wings working side by side, rather than top to bottom, maximize thrust and lift.Hu said these kinds of physics and aerodynamics lessons – and many more – need to be learned before engineers can design effective nano- and micro-scale vehicles.

And so he’s getting students immersed in the studies.

Hu has won a $150,000, three-year National Science Foundation grant that sends up to 12 Iowa State students to China’s Shanghai Jiao Tong University for eight weeks of intensive summer research. The students work at the university’s J.C. Wu Aerodynamics Research Center to study bio-inspired aerodynamics and engineering problems.

“We’re just now learning what makes a dragonfly work,” Hu said. “There was no need to understand flight at these small scales. But now the Defense Advanced Research Projects Agency and the Air Force say there is a need and so there’s an effort to work on it. We’re figuring out many, many interesting things we didn’t know before.”

Grad student, professor advance soil test technology invented by emeritus professor

An Iowa State University geotechnical engineering research duo has automated a soil strength test invented by an Iowa State civil engineering professor emeritus.Jeramy Ashlock, assistant professor and Black & Veatch Building a World of Difference Faculty Fellow, and geotechnical engineering Master’s graduate Ted Bechtum have automated the Borehole Shear Test (BST), an on-site soil strength test used for landslide analysis, stream-bank stability, and in early stages of building and highway construction. The BST has been used to study a diverse range of problems ranging from the impact of river bank caving on the Great Barrier Reef in Australia to major dams and other earth construction in China.Conventional direct shear testing requires bringing soil samples back from the field to test in the laboratory. The BST process is much quicker, allowing data to be collected on site. While one traditional test can take several days, the BST process can give results in one hour. By automating the BST, the efficiency and simplicity of the test is increased even further. Geotechnical engineers are able to repeat more tests in a given time than ever before. The automated BST also provides time-histories of shear stress and shear displacement. This creates possibilities for future applications, such as improving assessment of liquefaction susceptibility of soils during earthquakes.To automate the BST, Ashlock and Bechtum added a stepper motor, a stepper controller, electronic pressure sensors, an electro-pneumatic pressure regulator, and created a software control program.Bechtum, under the guidance of Ashlock, started the project to automate the BST in summer 2010. That spring he had just taken CE 360 (Geotechnical Engineering), where he discovered his love for geotechnical engineering. “Soil properties are open for interpretation, which I find intriguing,” Bechtum said. “I also found the BST project very practical and ready for future use in the field.”Bechtum defended his thesis on the Automated BST (ABST) in November. He earned his BS in civil engineering from Iowa State in December 2011 and will earn his MS in civil engineering this December as part of the concurrent BS/MS program offered at Iowa State.Anson Marston Distinguished Professor Emeritus Richard Handy (PhDCE’56) and his company, Handy Geotechnical Instruments, worked with Ashlock and Bechtum to automate the test he invented in the 1960’s. Handy taught geotechnical engineering at Iowa State from 1956-91.Ashlock and Bechtum licensed the ABST control program through the Iowa State University Research Foundation. Sales of the automated program they developed grant royalties to the research duo.In January 2013 Bechtum became a geotechnical engineer for Burns & McDonnell in Kansas City.

ECPE Researcher Completes Lab on a Chip Device

Liang Dong recently completed research on a device that can help scientists find more effective ways to protect crops and combat Parkinson’s disease by studying, of all things, worms.Nematodes possess simple nervous systems, but still share important characteristics with the nervous systems of humans. By studying nematode nerves, researchers can learn more about the human nervous system and how diseases such as Parkinson ’s disease affect it. In addition, learning more about the nematode nervous system allows researchers to devise more advanced pesticides to fight pathogens.Over the last eighteen months, Dong, assistant professor in the Iowa State University Department of Electrical and Computer Engineering , has worked with Richard J. Martin, professor of biomedical sciences in the College of Veterinary Medicine, and ECpE graduate students Peng Liu and Depeng Mao, to develop a device that can detect the muscular force of nematodes. The finished device, a “lab on a chip”, can detect such force with greater accuracy, efficiency, and cost-effectiveness than existing methods. Dong’s research was supported by the National Science Foundation and the McGee-Wagner Research Fund.“The device is small, cost-effective, accurate, and disposable,” Dong said. “I can see a lot of people who will be interested in that.”The device measures only about .25 square inches and features many tiny, micro fabricated channels. It uses two optical fibers; one single-mode fiber and one multimode fiber. The single mode fiber allows researchers to send a light into the fiber. The multimode fiber then detects the intensity of that light when a worm navigates through the channels. The device itself measures the change in the single-mode fiber’s light intensity; the greater the light intensity, the greater the actual muscle force generated. The device uses multiple detection points, which ensure far greater accuracy by averaging the recorded data from each point.With such a complex function to explore, why use nematodes for these kinds of experiments? For one, they’re inexpensive, and can be purchased hundreds at a time for a few dollars. Their one-millimeter size also makes them easy to handle in a laboratory, not to mention the tiny lab on a chip.According to Dong, 35-percent of the genes in a Caenorhabditis elegans (or C. elegans) nematode are similar to the genes of human beings. Nematode samples are simple, easy to study, and still retain enough similarity to humans to have practical applications. The researchers used a different type of nematode than the C. elegans in the experiment, but the technology the group developed can be adapted to measure the C. elegans without modification.The research, which was featured in Vertical NEWS and published in Lab on a Chip as “An integrated fiber-optic microfluidic device for detection of muscular force generation of microscopic nematodes”, has an impact that goes far beyond nematodes. Dong’s research on nematode systems can be adapted for use on human nervous systems, and can help provide valuable data on conditions like Parkinson’s disease.“A sensor for nematodes will help biologists studying the nervous system towards finding a way to help patients with Parkinson’s,” Dong said.Further, measuring muscular force can show how resistant the worms are to specific chemical combinations. Researchers can use data collected from Dong’s lab on a chip to devise chemical combinations for which nematodes and other pathogens have no resistance. This could lead to breakthroughs in the science of crop protection and provide farmers with more advanced pesticides that kill pests but preserve the environment.“There are many kinds of parasites and pathogens out there, and most of them have developed some level of resistance,” Dong said. “A critical issue is how to kill parasites and pathogens while protecting the environment. You want to accurately measure their drug resistance to find the proper methods to deal with them.”The next step in Dong’s research is to find opportunities in the biomechanics industry to develop an official prototype device that can then be commercialized. Dong is confident that companies and organizations will see the benefits of his design.

October 25, 2012 by Thane Himes

Professor Invents Sewer Pipe Made of Recycled Plastic, Fly Ash

Pipe-and-materials_David-White-patentDavid White, the Richard L. Handy Endowed Associate Professor in geotechnical/materials engineering, has invented a sewer pipe made of recycled plastic soda bottles, plastic fibers and fly ash.“America’s infrastructure currently has about 600,000 miles of sewer pipes, much of which is older than 30 years and in need of repair,” White says. “I feel that we must find a pipe made of more sustainable, sewage-resistant materials to accommodate our sanitary needs.” Sulfuric acid, commonly found in sewage, is slowly disintegrating the current concrete sewer pipes in municipalities throughout the U.S.White’s patented solution combines recycled, post-consumer waste polyethylene terephthalate (typical soda bottle plastic), fly ash (coal remains after use in power plant), and plastic fiber reinforcement. This sewer pipe invention is lighter and stronger than conventional sewer pipe made of Portland cement concrete. White’s solution also has higher structural capacity, is more resistant to acid and is less dense.  The new pipe material is more environmentally friendly, too, which White is especially proud of. “By using recycled soda bottle plastic, significantly less crude oil is used than using petroleum-based virgin plastic.” To test his invention, White gathered 99 percent of the materials locally. Plastic soda bottles came from Iowa State campus bottle collections; fly ash came from burnt coal at the Ames Municipal Power Plant; and plastic fibers (1 percent) were ordered from a supply company.The research work conducted by White has demonstrated that technology is feasible for making laboratory-scale pipe sections 12 inches in diameter.  The next stage in the development process will be full-scale production trials, for which White seeks industry partners with interest in commercializing the technology.White received a U.S. patent for this “Polymer mortar composite pipe material and manufacturing method” on October 25, 2011.

October 17, 2012 by Chris Neary

Evolving Microbes Help Iowa State Engineers Turn Bio-Oil into Advanced Bio-Fuels

Microbes are working away in an Iowa State University laboratory to ferment biofuels from the sugar and acetate produced by rapidly heating biomass such as corn stalks and sawdust.

But it’s not an easy job for E. coli and C. reinhardtii.

The bacteria and microalgae, respectively, don’t like something in the bio-oil produced by fast pyrolysis – the rapid heating of biomass without oxygen and with catalysts. The result of the thermochemical process is a thick, brown oil that smells like molasses.

A research team led by Laura Jarboe, an Iowa State assistant professor of chemical and biological engineering, is feeding the bio-oil (also known as “pyrolytic sugars”) to the microbes. The E. coli are supposed to turn the levoglucosan in the sugar-rich fraction of bio-oil into ethanol and lactic acid; the C. reinhardtii are supposed to turn acetate-rich fractions into lipids for biodiesel.

It’s part of the hybrid approach Iowa State researchers are using to produce the next generation of biofuels. They’re combining two conversion paths – thermochemical and biochemical – to find efficient ways to produce renewable fuels and chemicals.

“The goal is to produce biorenewable fuels and chemicals in a manner that’s economically competitive with petroleum-based processes,” Jarboe said.

There are, however, contaminants and toxins in the bio-oil that are getting in the way of the fuel production. Jarboe and a research team are experimenting with pre-treatments of the bio-oil that could reduce the toxicity. And they’re working to develop microbes that can tolerate the contaminants.

In addition to Jarboe, the research team includes Robert C. Brown, the Iowa Farm Bureau Director of Iowa State’s Bioeconomy Institute, an Anson Marston Distinguished Professor in Engineering and the Gary and Donna Hoover Chair in Mechanical Engineering; Zhiyou Wen, an associate professor of food science and human nutrition; Zhanyou Chi, a post-doctoral research associate for Iowa State’s Center for Sustainable Environmental Technologies; Tao Jin, a doctoral student in chemical and biological engineering; and Yi Liang, a doctoral student in food science and human nutrition. The project is supported by a three-year, $300,000 grant from the National Science Foundation and a three-year, $315,020 grant from the Iowa Energy Center.

The researchers are using a technique called directed evolution to produce microbes that are more tolerant of the contaminants in bio-oil. The microbes are grown with higher and higher concentrations of bio-oil and as they divide, they replicate their DNA. Sometimes there are replication mistakes that lead to mutations.

“It could be a mistake that’s immediately lethal,” Jarboe said. “Or it could be a mistake that helps the microbe tolerate the problematic compounds and it grows faster.

“At the end of the process, we want to say, ‘Hey, I’ve got a great bug.’”

Every day researchers check the experiments for signs of progress. So far, Jarboe said the evolving bacteria and microalgae have been able to tolerate slightly higher concentrations of bio-oil.

When mutations eventually produce a better breed of microbe, the researchers will analyze genomic data to learn and understand the important mutations. That will allow researchers to duplicate the microbes for better biofuel production.

Jarboe said development of those hungry, robust microbes could lead to important advancements in biofuel production: a hybrid process that’s biorenewable, fast, cheap and doesn’t depend on food crops as a source of biomass.

October 12, 2012 by Mike Krapfl