At-Home Disease Testing: Designing Microfabricated-Paper Sensors For Biomarker Detection

nanostructure sensor surface
A nanostructure sensor surface that can be used to detect chemicals, including disease biomarkers, at very low levels of concentration.

Imagine testing for cancers, hepatitis and tuberculosis as quickly, easily and inexpensively as today’s home pregnancy tests and blood glucose monitoring strips. Cyclone engineer Meng Lu is using the power of microfabrication to create state-of-the-art, on-demand diagnostic technology.

Lu, an assistant professor in both electrical and computer engineering and mechanical engineering, says the key to creating an at-home disease sensor is altering a common at-home material: paper. In a project supported by a National Science Foundation CAREER Award, he is developing the first sensor that uses engineered paper to combine the two parts of biomarker detection – sample preparation and detection – into one small sensor.

“Normal paper is made up of a random arrangement of cellulose fibers. By microfabricating the cellulose nanofibers into controlled structures, we can use paper’s natural ability to move and filter liquids to separate out just the biomarker molecules we are interested in testing. Microfabricating atoms also allows us to create unusual optical responses not found in everyday paper.”

The technique, called optofluidic paper, offers significant advantages over traditional diagnostic tests. Lu’s sensor will be able to test for multiple biomarkers at the same time, just by building several different types of nanostructures of atoms into one paper test strip. And optofluidic sensors detect biomarkers at very low concentrations, enabling earlier disease detection – and perhaps allowing patients to avoid more invasive tests.

Lu will pair the sensor with a small, portable, inexpensive device that quickly measures optical feedback from the engineered paper and turns it into easy-to-read results. “We will engineer the paper to adhere to  biomarker molecules, so the texture of the paper will change when it comes in contact with even very small quantities of the biomarker,” says Lu. “We can then measure changes in how the light interacts with the paper to see if the biomarker is present.”

What’s more, since Lu’s sensors are paper- based, they will be low-cost and disposable.

“Optofluidic paper sensors fill a significant need in areas with limited medical facilities, such as rural communities, developing countries and military deployments,” says Lu. “This technology will bring inexpensive and reliable testing right to patients’ bedsides.”

Educating Today’s Engineers: Examining How, Why and When New Technology Tools Improve Engineering Education

Benjamin Ahn
Benjamin Ahn, assistant professor of aerospace engineering

Benjamin Ahn’s research goal is to identify the best educational approaches for educating new generations of engineers, using technology tools available today.

“The next generation of engineers will face new challenges, and we have new technology tools to help educate and prepare students,” says Ahn, assistant professor of aerospace engineering. “But technology is only as good as how we use it. Understanding what techniques work best, and why, is the first step to offering evidence-based best practices that develop outstanding future engineers.”

Ahn studies three approaches that can help improve educational experiences for undergraduate students in engineering.

Technical content mastery

Ahn is investigating how technology can help engineering students master the technical content in their fields. He is studying how students in large-enrollment foundational engineering courses use and respond to instructional videos.

Some initial findings are surprising (videos any length between 1 and 20 minutes are played and completed at the same rate), while others match expectations (videos are most watched in the few days before exams). Ahn will use his research results to make evidence-based recommendations for how instructors can use video to facilitate student learning in engineering courses.

“Improving how we teach technical courses is hugely important because the classes form the foundation of an engineer’s knowledge, and large-enrollment courses can be particularly challenging for students, including those who are underrepresented in engineering. Engagement and success in first- and second-year courses is key to engineering student retention,” says Ahn.

Polished professional skills

Knowing technical engineering content is a must, but in today’s globalized, collaborative world, it’s no longer enough. Tomorrow’s engineers will need exceptional skills in teamwork, particularly working with those in different disciplines and from different cultures. Ahn is also studying how to best instill and assess students’ professional skills.

“Professional skills cannot be taught or measured on paper, so I’m particularly interested in using technology and hands-on practice to convey information and conduct real-time, holistic assessments of students’ development in systems-level thinking, communication, ethics and all the skills our future engineers will need,” says Ahn.

Valuable research mentoring

“Successful engineers apply and generate new technical content to help expand their fields, so giving students practice in undergraduate research experiences is a must,” says Ahn. “And one of the most important aspects to high-quality research experience is receiving mentoring from more experienced engineers.”

Ahn is pioneering the use of technology to better understand what parts of complex mentoring relationships are key to creating positive student experiences. He is developing new ways to measure mentoring practices and understand effects of positive mentoring on student outcomes, all with an eye on creating a research-based mentoring training program.

Modern Grid: Linking U.S. Electrical Systems to Move Renewable Energy and Increase Reliability

James Mccauley
Iowa State’s James Mccauley describes computer models showing the effects of tying the country’s major power grids together. Photo by Werner Slocum, NREL/DOE.

James McCalley is working with researchers from across the nation to find ways to tie the United States’ largest – but separate – electricity grids together. In a study that is part of a U.S. Department of Energy $220 million Grid Modernization Initiative, McCalley and his Iowa State University researchteam are building computer models simulating 15 years of grid improvements and operations to study the best ways to generate renewable power and transmit it to and from the major eastern and western U.S. grids.

McCalley’s team is evaluating four different designs, ranging from maintaining existing limited cross-grid capacity to creating a new macrogrid that establishes connections between the West Coast and the Midwest.

Models indicate that there is good reason to connect and modernize the county’s largest energy grids.

“There are two main drivers for benefits of ‘cross-seam’ transmission,” says McCalley, an Anson Marston Distinguished Professor of Engineering and the Jack London Chair in Power Systems Engineering in the department of electrical and computer engineering. “That’s wind energy moving from the middle of the U.S. to the coasts and sharing the capacity between regions for reliability purposes. In Iowa, about 35 percent of our electricity is renewable energy. If we want the rest of the country to be at 35 percent renewable energy, this is what you want to do.”

Firm Foundations: Refining Pile Design Models For Earthquake-Resistant Buildings

Jeramy Ashlock
Jeramy Ashlock, Richard L. Handy Professor of Civil, Construction and Environmental Engineering

Many researchers say they want to shake up their fields of study. Iowa State engineer Jeramy Ashlock means it. Ashlock, the Richard L. Handy Professor of Civil, Construction and Environmental Engineering, studies how building and bridge foundations interact with soil during earthquakes and structural vibrations.

In research funded by an National Science Foundation CAREER award, Ashlock and his team are conducting full-scale field tests of the dynamics of piles, large steel or concrete foundations that are driven into the ground to support structures. They will test piles with a large servo-hydraulic shaker that applies random and multi-frequency excitations like those of an earthquake and record the physics of what happens.
Ashlock will use the experimental results to refine computer models that civil engineers use to help make pile design decisions. To accurately capture how the pile responds in reality, researchers must account for many complex variables: vertical, horizontal and lateral movement – along with the pile’s effects on the soil beneath it, around it and even soil far away from the pile.
“Measuring and modeling pile performance is an incredible challenge,” says Ashlock. “In our study, we’re ratcheting up the complexity and examining real-world conditions to verify some of the phenomena we have observed in simplified, scale-model centrifuge laboratory tests. Knowing more about real-world pile conditions will make it possible for us to recommend real-world design improvements for buildings and bridges.”

Middle Ground: Examining Farm Field Drainage to Develop Balanced Agricultural Practices

Matt Helmers with farmers in field
Matt Helmers’ (pictured second from left) mission is to put the “middle ground” in managing agricultural land.
Matt Helmers’ mission is to put the “middle ground” in managing agricultural land. Crops need enough but not too much water in the soil. Agricultural producers seek to get just the right amount of nutrients to plants, without the excess traveling elsewhere.
“The overall goal of my research in water quality and drainage flow is to look for ways to maintain agricultural productivity while reducing our environmental footprint,” says Helmers, who is a professor of agricultural and biosystems engineering. “Better understanding of how water drains from fields will help us design balanced agricultural practices for the future.”
Helmers collects subsurface data on both the volume of water that drains from cropland and the nutrient content found in water samples. The team combines current information with more than 25 years of historical drainage data to help form a clearer picture of the amount of water needed for best crop production, how much and when extra water is available for capture and irrigation reuse, and amounts of nutrient movement.
“No other state has the wealth of data that we do on drainage and water quality,” says Helmers. “That positions Iowa State University well to answer current questions and make predictions about agricultural water needs under the changing rainfall patterns we expect to see in the future.”




Data Driven: Smart Systems For Traffic Management

Realtime Analytics for Transportation Lab
Cyclone transportation researchers use the Realtime Analytics for Transportation Lab as a testing ground for emerging traffic data analytics.
Cyclone engineers are using big data to make big improvements to road safety and traffic management. Anuj Sharma, associate professor of civil, construction and environmental engineering, and a team of researchers are using continuous traffic data streams – video, traffic volume, speed, backups, weather and more – to build automated, real-time traffic management tools.
With support from a $1 million grant from the National Science Foundation, the team is working with the Iowa Department of Transportation to develop new traffic models, computer algorithms, user-friendly computer displays and information visualizations that will help traffic management operators make decisions and take actions to keep vehicles moving smoothly.
Ultimately the goal is to build a system that can use machine learning to detect – and even predict – traffic problems. Fast responses to traffic troubles like crashes, stalled cars or bad weather will help improve the safety of motorists and workers by reducing response times and rapidly slowing or re-routing traffic in trouble spots. “When there’s a crash, every second is critical,” says Neal Hawkins, associate director of Iowa State University’s Institute for Transportation and adjunct lecturer in civil, construction and environmental engineering.




New Nylon, New Possibilities

Zengyi Shao and Jean-Philippe Tessonnier
Zengyi Shao (left) and Jean-Philippe Tessonnier

Cyclone engineers Zengyi Shao and Jean-Philippe Tessonnier created a new type of biobased nylon that outperforms nylon created from petroleum chemicals. Shao and Tessonnier, both assistant professors of chemical and biological engineering, combined their expertise in biocatalysis and chemical catalysis to design a hybrid biomass-to-nylon process that integrates fermentation and downstream upgrading. This hybrid process offers many advantages: the entire conversion is performed under near-ambient conditions, the fermentation broth is converted directly without any purification and the fermentation broth provides the reagents for the second step of the process.

What’s more, the final product, bio- advantaged nylon-6,6, has an extra double chemical bond in its backbone, which can be used to tailor the material’s properties in all kinds of useful ways. The double bond is an anchoring point to add extra molecular chains that can make the biobased nylon hydrophobic, antistatic, antimicrobial, flame retardant and more.

“We’re making new molecules that will enable development of new products not possible before using traditional petroleum- based nylon,” says Tessonnier.



Bubbling With Renewable Fuel: Nanoscale Catalyst Splits Hydrogen From Water Quickly and Efficiently

iron-nickel phosphide nanoparticle
An iron-nickel phosphide nanoparticle catalyst splits hydrogen from water.

At the macroscale, rust is a common, everyday material. But at the nanoscale, it might hold the promise of sustainable clean energy. Shan Hu, an assistant professor of mechanical engineering, is developing new catalysts made of rust nanostructures that convert light into fuel faster and cheaper than other leading catalysts.

“Rust, or iron oxide, is an excellent example of how seemingly ordinary materials show very unusual, useful properties when we make them into nanostructures,” says Hu. “At the nanoscale, iron-oxide becomes photosensitive, able to absorb sunlight and convert it into electrons. That opens up the door to many new possibilities.”

One such possibility is using iron-oxide nanostructures to drive hydrogen out of water in a process called water splitting. Driving, or “cranking,” hydrogen from water is a first step in using hydrogen as a renewable fuel source, but the process comes with many challenges.

“Typically, these types of reactions happen really slowly, reducing how many electrons transfer from the iron-oxide to the water and crank out the hydrogen,” says Hu. “So, we developed a new type of nanoparticle catalyst to speed up and improve the reaction.”

Hu and her research team found that their new nanoscale iron-nickel catalyst can beat the performance of ruthenium, a benchmark water splitting catalyst material. And, replacing the scarce and expensive ruthenium with abundant and cheap iron and nickel helps reduce costs.

Hu’s catalyst also requires less voltage to activate the reaction than other water-splitting processes. “Usually this type of reaction requires 1.5 or 1.6 volts to crank the hydrogen, but our new catalyst does the job with only 1.2 volts, a huge energy savings,” says Hu.

After making the breakthrough in water splitting, Hu has now turned her attention to harnessing the potential of nanostructures in other areas.

“We have a lot of big challenges facing society – energy needs, illnesses – just to name two. The never-seen-before abilities of nanostructures may be the new piece of the puzzle we need to solve our pressing problems,” says Hu.



Jump-starting battery advancements

Steve Martin
Steve Martin of materials science and engineering has won a grant to study new and safter materials for batteries.

Solid electrolytes are key to making batteries more powerful and safer

For more than 30 years, Steve Martin has been studying and characterizing different materials to identify properties that would allow for optimal energy transfer and storage in batteries. He says ceramic-like sulfide glasses may hold the solution, and now he’s working on a project to scale up his fundamental research and ultimately assemble and test batteries with this technology.

Martin, an Anson Marston Distinguished Professor in Engineering in Iowa State University’s Department of Materials Science and Engineering and an associate of the U.S. Department of Energy’s Ames Laboratory, says his life’s work is inspired by the need to reduce the world’s reliance on fossil fuels.

“We’ve realized the negative consequences of burning oil, and we need to find ways to improve batteries to better support alternative energy sources and applications, like wind energy and electric automobiles,” he adds.

Martin’s latest project aims to create a new type of electrolyte based on solids instead of the liquid electrolyte we see in today’s lithium-ion batteries.

“The electrolyte’s job is to separate a battery’s electron-producing anode from its electron-accepting cathode. Because liquid electrolytes are highly flammable, batteries have been purposely designed with 10 times less energy density than is actually possible to avoid catching fire,” he explains.

The solid electrolyte Martin is developing is stronger and non-flammable compared to liquid electrolytes. These two factors alone will allow the researchers to create a battery that can store more energy at a higher voltage and that is safer for a wider range of temperatures, both hot and cold.

Finding the right chemistry for these electrolytes has taken Martin and several other researchers years to discover, but it’s been worth the wait. The new batteries will essentially be thin film, manufactured in such a way that they will be denser and more durable, and they will help improve a range of alternative energy technologies.

Martin’s work is most recently supported by a three-year, $2.5 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency – Energy and its new Integration and Optimization of Novel Ion-Conducting Solids (IONICS) program. There’s additional, cost-share funding from Iowa State and the Iowa Energy Center.

The funding also supports the work of Jing Xu, a newly hired assistant professor of materials science and engineering, three postdoctoral researchers, two doctoral students and three undergraduates.

“With Dr. Xu’s expertise in assembling and testing batteries and my understanding of making electrolytes, we’re going to see some significant advancements through this project,” Martin says. “It’s great to see momentum picking up around battery research, because I know progress in this area will bring tremendous value to society.”

FactBoard: Visualizing Data

Guiping Hu
Guiping Hu, associate professor of
industrial and manufacturing
systems engineering

Creating a real-time data-driven visual decision support system for the factory floor

Guiping Hu has set out to make manufacturing production more efficient. The associate professor of industrial and manufacturing systems engineering is working on a project for the Digital Manufacturing and Design Innovation Institute (DMDII) to develop a shop floor decision support system called FactBoard.

DMDII is a federally-funded research and development organization of UI LABS focused on projects that demonstrate and apply digital manufacturing technologies to increase the competitiveness of American manufacturing. Hu says FactBoard fits the bill because it will help manufacturers respond to changes in real  time.

The project aims to convert thousands of existing, real-time data inputs into a collection of visual dashboards, creating a record of transactional data that can be used to make informed decisions about production.

“Each manufacturing floor is different – there may be a logistics problem or a production process that needs adjusted,” Hu says. “With FactBoard, we can use information based on data that is already available, set up parameters and organize data based on the needs of each shop.”

At Iowa State, four faculty members, five graduate students and several undergraduate research assistants are helping Hu with the project. Hu’s also working with Boeing, John Deere, Proplanner and Factory Right to develop the technology.

The group has been surveying manufacturing floors to identify 5-10 key problems that are common across industries. Narrowing that list down hasn’t been an easy task, but it’s why Hu says having a range of companies involved at the beginning of the project is so important.

She adds that because she has such a wide audience for FactBoard, the team is creating a system that can be incorporated within individual IT frameworks through XML integration methods.

Once FactBoard is implemented, Hu says manufacturing facilities can use it to improve how they manage inventory and on-time delivery methods as well as the efficiency and effectiveness of production equipment.


Ecosystems of support

Joe Zambreno
Joe Zambreno, associate professor of electrical and computer engineering

Promoting an accessible, responsive approach to engineering education

A new initiative in the Department of Electrical and Computer Engineering will help a pool of talented students pursue a degree in engineering.

The project, called ECSEL: Electrical, Computer, and Software Engineers as Leaders, is part of the National Science Foundation’s Scholarships in Science, Technology, Engineering, and Mathematics (S-STEM) program, which provides financial support to help low-income, academically talented students obtain STEM degrees and enter the workforce or graduate study.

The program will fund 582 scholarships over the next five years for students majoring (or preparing to transfer) in electrical engineering, computer engineering and software engineering.

“We’re also creating what we are calling an ecosystem of academic and co-curricular support for these students, providing them with an experience that will not only encourage them to stay in their STEM field of choice but also give them the tools to excel,” says Joe Zambreno, associate professor of electrical and computer engineering and principal investigator of the project.

The program is a multi-institutional, collaborative partnership between the Department of Electrical and Computer Engineering, Program for Women in Science and Engineering, Des Moines Area Community College and Kirkwood Community College, and Zambreno says the group will leverage the individual successes of each partner as the program grows.

“We are looking at the entire process of earning a degree in STEM and identifying ways to make it better, whether it’s making sure classes transfer from community college to Iowa State or offering leadership development opportunities that keep the students engaged in their learning and growth,” he adds.

An important aspect of the project will be the team’s research studies of the ecosystem of supports that will accompany the project. Zambreno says the group will investigate how underrepresented minorities, including women, in STEM fields develop their professional and career identity using both qualitative and quantitative metrics.

“Knowing what motivates individuals can help us make adjustments to the learning environment we offer,” he adds. “The more we can do to encourage diversity in thought and culture in STEM, the better the fields will be.”

Characterizing antimicrobial resistance

Adina Howe, Heather Allen, Tom Moorman, and Michelle Soupir
Adina Howe, assistant professor of agricultural and biosystems engineering, Heather Allen and Tom Moorman from USDA’s Agricultural Research Service, and Michelle Soupir, associate professor of agricultural and biosystems engineering.

Interdisciplinary team uses systems approach to sequence microbial genes

Historically, treatments for disease-causing microorganisms have relied heavily on the use of antimicrobial drugs.

Adina Howe says this very practice (both when it’s used properly and when it’s misused), along with naturally occurring phenomena, has accelerated how quickly microorganisms are evolving into resistant strains.

“If we continue to see bacteria, fungi, viruses and parasites increasingly becoming resistant to antimicrobial drugs, common treatments for infections and minor injuries will become ineffective,” explains Howe, an assistant professor of agricultural and biosystems engineering.

She adds that other factors, like poor infection control practices, inadequate sanitary conditions and inappropriate food handling, can encourage the spread of antimicrobial resistance.

To better understand antimicrobial resistance and how it enters the environment and food chain, Howe is leading a research team that is studying the phenomenon in agricultural environments.

The multidisciplinary group, which includes Michelle Soupir, an associate professor of agricultural and biosystems engineering at Iowa State, Heather Allen and Tom Moorman from USDA’s Agricultural Research Service, and Shannon Hinsa, an associate professor of biology at Grinnell College, recently received a nearly $1 million, three-year grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

The group will be using a systems approach in its research, adding insight from engineering, microbiology, soil science and health experts.

Iowa State’s team is working to improve a technology that Howe designed to efficiently sequence the genes of microbes. The tool, called DARTE-QM, will allow the group to hone in microbial resistant gene reservoirs in the environment.

To begin its work, the team is studying manure, soil and water samples gathered from swine operations.

“Using DARTE-QM, we can take DNA from the environment and look at its fingerprint to identify bacteria and which genes might allow antimicrobial resistance to develop. We can target hundreds of resistant genes at the same time,” Howe explains.

The group will also consider environmental factors, like production practices or weather-related occurrences, as it studies where antimicrobial resistance occurs and why it continues.

Howe says the group also studies various strategies to mitigate the emergence, spread and persistence of antimicrobial pathogens, and that this endeavor absolutely requires input from multiple disciplines and perspectives. Currently, the team is evaluating the effectiveness of various manure storage strategies and their impact on reducing resistant bacteria.

“If everyone on this team wasn’t participating in this project, there’s no way we would be able to accomplish our goals,” Howe says. “It’s a whole team of dedicated, hardworking people who bring their expertise to solve a very challenging problem. The end result will be a better understanding of how resistance develops and how we might reduce it.”

Safer, more sustainable aviation

Des Moines International Airport pavement testing area
Halil Ceylan’s research team has built the world’s first electrically conductive heated pavement test site at an airport. This photo shows the technology performing well during a snow event on Dec. 10, 2016, at the Des Moines International Airport.

Iowa State’s partnership in FAA program advances airport runways, operating technology

Engineers from Iowa State are part of a collaborative partnership to help navigate and improve the complex, ever-changing aviation industry with innovative ideas and new research projects.

“When you look at addressing any problem in the field, from the weather to security to operational efficiencies, you know it’s going to take a community of minds coming together to create solutions,” says Halil Ceylan, professor of civil, construction and environmental engineering and director of the Program for Sustainable Pavement Engineering and Research at Iowa State’s Institute for Transportation.

Ceylan also serves as a site director for the Federal Aviation Administration’s Center of Excellence Partnership to Enhance General Aviation Safety, Accessibility and Sustainability, or PEGASAS.

The partnership, which was established in 2012, is led by researchers at Purdue University and includes Iowa State, The Ohio State University, Georgia Institute of Technology, Florida Institute of Technology and Texas A&M University as core members.

Together, the researchers are working with the federal government and industry to study a variety of general aviation issues.

Ceylan is using his expertise in pavement engineering to lead a project that aims to create a hybrid heated pavement system. The system includes electrically conductive concrete, nanostructured superhydrophobic coatings and hydronic heated pavements that will keep airport pavement surface temperature above freezing during winter weather operations and reduce airport incidents related to unfavorable conditions.

Iowa State researchers are contributing to several other projects, including developing an FAA pavement marking presence tool, analyzing and processing data regarding airport safety, and testing how LED lighting performs under extreme conditions.

Ceylan says he’s also excited about the student outreach component of PEGASAS. Two Ph.D. students from Iowa State were able to travel to FAA’s William J. Hughes Technical Center for two months to learn and apply their skills in a real-world setting.

“I participated in a similar fellowship as a graduate student, and I can honestly say it changed the trajectory of my career in such a positive way. It’s programs like these that will help shape the future of the aviation field. We have so many brilliant minds with so much to offer, we just need a way to get them involved, and PEGASAS is a great way to do just that.”

Increasing electric steel performance

Jun Cui
Jun Cui, associate professor of materials science and engineering and senior scientist at the Department of Energy Ames Laboratory

Materials research will make electric motors more efficient, cost effective

Can electric steel, a popular material that’s already a key functional material for modern society, get better? Jun Cui, an associate professor of materials science and engineering and a senior scientist at the U.S.  Department of Energy Ames Laboratory, says it can.

That’s why he’s leading a team of researchers who want to increase the amount of silicon in electric steel to 6.5 percent. If the group succeeds, the new steel can be used as the stator material to create an efficient, sustainable, non-rare-earth electric motor.

The team is currently working on a project that would advance electric steel to be used in the motors of electric vehicles. The work is supported by a three-year, $3.8 million grant from the DOE’s Vehicle Technologies Program.

Cui says using electric steel to develop the magnetic stator core of a motor can reduce eddy currents and heat and power loss in the motor. The motor would then be able to run at higher frequencies and have a higher power density, resulting in a smaller, more efficient motor.

To get to this point, the team has to overcome an issue with electric steel – it becomes brittle once you reach more than 4 weight percent silicon.

“When iron atoms are being mixed with a large number of silicon atoms, the brittleness comes from the silicon atoms having time to find each other and pair up,” Cui explains. “To bypass this brittleness, we are rapidly cooling the alloy so the silicon atoms have no time to pair.”

The work combines modeling and experimentation, and brings in research partners from the United Technologies Research Center in East Hartford, Connecticut; and the University of Delaware in Newark.

Experts from Iowa State and the Ames Laboratory will also contribute to the project, including Scott Chumbley, a professor of materials science and engineering and scientist for the Ames Laboratory;

Peter Collins, the Alan and Julie Renken associate professor of materials science and engineering and an associate scientist of the Ames Laboratory; Iver Anderson, a senior metallurgist for the Ames Laboratory and an adjunct professor of materials science and engineering; Valery Levitas, a Schafer 2050 Challenge Professor of aerospace engineering and an associate scientist of the Ames Laboratory; Frank Peters, an associate professor and associate chair of operations in industrial and manufacturing systems engineering; and Matthew Kramer, director of the Ames Laboratory’s Division of Materials Sciences and Engineering and an adjunct professor of materials science and engineering.

Self-destructing batteries

Reza Montazami with graduate students
Reza Montazami (center) with graduate students, Reihaneh Jamshidi (left) and Yuanfen Chen.

A practical solution for powering transient electronics

Researchers at Iowa State have made significant progress in an effort to make transient electronic devices completely autonomous.

Reza Montazami, an assistant professor of mechanical engineering and an associate of the U.S. Department of Energy’s Ames Laboratory, is leading a team that has developed a transient lithium-ion (Li-ion) battery that offers nearly the same voltage as commercial products and can disintegrate in 30 minutes.

These transient batteries, and the materials research and structural design behind them, will be crucial as the field of transient
electronics continues to grow.

“Devices that operate for short, defined periods of time and then self-destruct can be used in a range of applications, from healthcare to military and homeland security,” Montazami explains. “They offer a great deal of promise, but they currently still rely on an outside, non-transient, power source. If we can change that, we can make the devices even more beneficial.”

And that’s exactly what Montazami has set out to accomplish.

He and his team have combined Li-ion battery technology with a new physical–chemical hybrid transiency approach that breaks down a battery and dissolves its electrodes.

transient battery
ISU scientists have developed a working battery that dissolves and disperses in water. Illustration by Ashley Christopherson.

“The casing for the battery uses polymers that swell when immersed in a liquid, causing the nanocomposite electrodes to break and  disperse,” he explains. “Because the battery is designed to disintegrate both chemically and physically, it is very difficult to trace back to the owner even if the device were still physically present.”

At this point, the batteries are 5 mm by 6 mm, and 1 mm thick and can power a desktop calculator for approximately 15 minutes. And while they don’t completely disappear, Montazami says he will continue experimentation to advance the technology because of the value it could bring to even mainstream electronics.

“If we look at the bigger picture, we could see a consumer battery that could be dissolved once a person was done using it instead of that battery ending up in a landfill,” he adds.

The team is continuing to study the physical–chemical hybrid transiency platform to improve understanding of what interactions are at play. The group is also working to improve the performance of the battery for devices that use more power. That could mean making electrodes with higher area density or finding ways to connect several batteries.

The road to biorenewable asphalt

a new $5. 3 million Bio-Polymer Processing Facility located at Iowa State’s BioCentury Research Farm
A new $5. 3 million Bio-Polymer Processing Facility located at Iowa State’s BioCentury Research Farm

Researchers scale-up plans to use soybean oil to produce bio-polymers

A new Bio-Polymer Processing Facility located at Iowa State University’s BioCentury Research Farm gives researchers a broader understanding of what it would take to commercialize bio-polymers so they can be added to materials like asphalt.

Eric Cochran, associate professor of chemical and biological engineering, and Chris Williams, the Gerald and Audrey Olson Professor of civil, construction and environmental engineering, have been working together since 2010 to develop bio-polymers with soybean oil.

The professors originally set out to create a soybean based styrene-butadiene rubber. Early in their research, a member of Cochran’s team figured out how to polymerize soybean oil into a thermoplastic. “A thermoplastic can be solid at room temperature, but if you heat it up you can make new shapes or dissolve it into another material such as asphalt. This is something that has not been feasible until now,” Cochran says.

Using the fundamental Flory-Stockmayer theory, the team can predict when a polymer system will gel. “The gelation is the point in which the individual polymer chains connect and form a giant molecule,” explains Cochran. “The goal is to stop the process right before the gelation point to achieve a thermoplastic.”

Discovering thermoplastics has fueled several projects over the years, including working with Argo Genesis Chemical LLC, a sister company to Seneca Petroleum Co. Inc., of Crestwood, Illinois. Williams, who manages the Institute for Transportation’s Asphalt Materials and Pavements Program, has partnered with Seneca for more than 20 years. He says the shared knowledge and resource has led to significant advancements.

The partnership also made the Bio-Polymer Processing Facility at Iowa State a reality. Argo Genesis Chemical built the pilot plant and turned it over to Iowa State last summer.

The plant, which was designed specifically to produce bio-polymers from soybean oil, contains several industrial tanks all connected through a series of tubes, pipes, wires and hoses. The sensors on the equipment must be extremely precise due to the sensitivity of the polymer and chemicals involved.

Cochran and Williams are working to get enough of the polymer into asphalt so it can be viable as an asphalt modifier, resulting in a more sustainable approach to paving roadways.

A new model of engineering education

Diane Rover, professor of electrical and computer engineering, promotes new educational approaches in the classroom through a new interdisciplinary project
Diane Rover, professor of electrical and computer engineering, promotes new educational approaches in the classroom through a new interdisciplinary project

Collaborative course design will transform education and develop the next generation of engineers

Electrical and computer engineering technologies have evolved from simple electronics and computing devices to complex systems that profoundly change the world in which we live.

Designing these complex systems requires a new way of thinking, including developing social, professional and ethical responsibility.

As these advancements continue, faculty members at Iowa State are transforming the way they educate and prepare the field’s future workforce.

A team from the Colleges of Engineering, Human Sciences, Design, and Liberal Arts and Sciences are working together to create a new instructional model for course design in electrical and computer engineering.

The project, “Reinventing the Instructional and Departmental Enterprise (RIDE),” received a $2 million National Science Foundation grant to transform approaches to teaching and learning in electrical and computer engineering, especially in relation to design and systems thinking, professional skills such as leadership and inclusion, contextual concepts, and creative technologies.

The changes in educational approaches will be driven by RIDE’s cross-functional, collaborative instructional model for course design and will lead to different department structures and a more agile environment able to respond quickly to industry and social needs–and ultimately serve as a model for electrical and computer engineering departments across the country.

Another impact of the RIDE project will be broadening the participation of underrepresented students, especially undergraduate women, in the field of electrical and computer engineering. Project activities will emphasize inclusive teaching practices and learning experiences.

The RIDE project began this summer by developing strategies for managing change processes. During the first year, the project strategies will get underway, and by the second year, new versions of selected courses will be piloted. The electrical and computer engineering department will continually develop and refine department and curricular practices.

The College of Engineering is currently in the process of hiring a new chair for the Department of Electrical and Computer Engineering. This individual will serve as the principal investigator for the RIDE project, joining 14 current members of the team that includes the College of Engineering’s Dean Sarah Rajala.

The project was awarded under an NSF activity known as “RED,” which was created to help universities transform department structures, policies, practices and curricula to enable groundbreaking changes in undergraduate engineering education.

Making progress toward invisibility cloaks

Liang Dong
Liang Dong, associate professor of electrical and computer engineering

Meta-skin suppresses scattering microwaves, hides objects from radar detection

Two professors in electrical and computer engineering have made significant headway in an innovative stealth technology.

Liang Dong, an associate professor who researches micro-nanofabrication, liquids and polymers, and Jiming Song, a professor who studies electromagnetics, have combined their areas of expertise to create a flexible, stretchable meta-skin material that can render an object virtually undetectable by radar.

The meta-skin is made of metamaterials, or man-made materials that have properties not found in nature. These materials include an array of split ring resonators (SRRs) embedded in layers of silicone sheets. The resonators are filled with the liquid metal alloy galinstan and create small, curved segments of liquid wire that can absorb radar waves.

The researchers stretched multiple layers of the meta-skins along the surface of an object in a planar direction while also changing the spacing between the meta-skin layers in a vertical direction to trap microwaves and reduce the reflected portion of the waves.

“Within our microwave testing chamber, we have successfully demonstrated a cloaking effect when we wrapped the meta-skin around a dielectric cylindrical rod,” says Dong. “We saw a suppressed scattered field, which is an improvement from the more traditional technologies in place that only reduce backscattering.”

These tests showed radar suppression was about 75 percent in the frequency range of 8–10 gigahertz.

While these advancements have fairly obviously applications for the military, the researchers also want to look at how to put this technology to use within different fields such as biomedical devices. They say they may be able to improve implanted medical devices that should not be exposed to microwaves or other electromagnetic waves.

Not to mention the possibility of creating a true invisibility cloak.

“We’ve seen that we can suppress microwaves, so we are now focusing on how to apply that same understanding to manipulate shorter wavelengths such as terahertz electromagnetic waves,” Dong said.

The current resonators can be tuned to absorbed different frequencies up to 9.15–12.38 GHz. Setting sights on shorter wavelengths could bring about more exciting cloak applications. “While this sort of technology would require new structures and design elements, we realize the potential is there to create it,” Dong says.

“This project started as a conversation about doing something interesting with wearable films, and we are excited about the results we’ve seen so far. We are looking forward to taking this concept to the next level.”

Nanostructures and Lego® Bricks

Ludovico Cademartiri (right foreground), assistant professor of materials science and engineering, and his research team use an interdisciplinary approach to tackle a wide range of challenges in materials science
Ludovico Cademartiri (right foreground), assistant professor of materials science and engineering, and his research team use an interdisciplinary approach to tackle a wide range of challenges in materials science

Advancing technology through practical and radical materials science

Materials science, chemistry, physics and life. These are the driving forces behind the research in Ludovico Cademartiri’s laboratory at Iowa State.

Cademartiri, assistant professor of materials science and engineering and associate scientist with the U.S. Department of Energy Ames Laboratory, says he and his graduate students work to go beyond understanding materials to exploring what’s happening at the edge of the discipline.

“The general approach of our lab is that we try to use our skills at making materials to answer fundamental questions, whether they are related to materials science, another discipline, or some space between,” Cademartiri explains.

The result is a good mix of interesting scientific problems, each with its own potential.

One project involves a big breakthrough but is also facing significant experimental challenges. The group wants to create a ceramic that behaves like a plastic. Combining the properties of these two classes of materials typically requires mixing them together in composites, which are difficult to process. No single material combines the properties of ceramics and plastics. Cademartiri says that while it’s considered fundamentally impossible, the group has evidence to the contrary.

“We’ve seen similarities between plastics and crystals when crystals are very thin, 50 thousand times thinner than a human hair. Plastics are composed of an entangled mess of thin strands, molecules specifically. These strands are very flexible in plastics, which allows them to behave the way they do. We have clear evidence that some extremely thin crystal strands are similarly flexible. Determining exactly how similar they are is important to apply these materials but is also extremely challenging.”

In another research program, the group has made significant headway in controlling microstructures in ceramics. The team has helped resolve an issue that had previously prevented making materials by selecting their individual components and then assembling and processing those components to create a material.

Cademartiri says in the past building a material from the bottom up has resulted in the material disintegrating during processing, making it hard to apply in devices. His team has found a new approach to avoid this issue entirely, thereby enabling an entirely new way of manufacturing materials with nearly complete control over their composition and structure. The findings will be published soon in two back-to-back articles in the journal Advanced Materials.

In a less traditional project, Cademartiri’s team has been working to use LEGO® bricks to simulate an ecosystem in the lab to study how plants interact with their environment. “We can control and understand pretty well a plant in isolation, but there’s so much more involved when you include the ecosystem wherein the plant exists,” he says. “If we can simulate this environment, and understand and predict how plants will respond to it, we should be able to improve the reliability of our food supply.”

While the group’s overall focus is to provide solutions for global problems (like improving food supply) and to resolve issues at the foundation of modern materials engineering (such as programming material properties, replacing extremely rare elements in materials, translating materials and processes from the lab to the outside world, and understanding what happens at the interface of two materials), Cademartiri says he encourages his team to think outside the box.

“Materials are, in most cases, the bottleneck in the development of new technology and new solutions,” he says. “Therefore, controlling materials or, in other words, knowing how to build things atom-by-atom, is one of the safest ways to have an impact on the world.”

Engineering better health

Surya Mallapragada, Carol Vohs Johnson Chair in Chemical and Biological Engineering
Surya Mallapragada, Carol Vohs Johnson Chair in Chemical and Biological Engineering

Polymeric biomaterials combined with nanoscale delivery devices can improve preventative medicine

Surya Mallapragada knows the value an engineering perspective can add to advancing the biomedical field.

For years, Mallapragada, the Carol Vohs Johnson Chair in Chemical and Biological Engineering, has been researching the best ways to synthesize copolymers and nanoscale delivery devices to treat illnesses. Now, she’s looking at ways to prevent disease.

“When we were focused on treatment technologies, we wanted to minimize the immune response to the drugs that were being delivered to a patient, creating an environment that would allow the medicine to be effective in fighting against a disease,” she explains.

Shifting her focus to preventative medicine like vaccines, Mallapragada says her team wants to maximize immune responses to different drugs so the patient is protected against a variety of diseases and stays healthy. “We have a good understanding of which chemistries will elicit the right response given the different applications,” she adds.

That information is being put to use within nanoscale drug-delivery devices Mallapragada’s team is designing. Her group is focusing on vaccines that carry just the proteins or DNA from pathogens, a change from traditional vaccines that have been created using live, or attenuated, pathogens.

“When we use attenuated pathogens, we have to consider a number of factors, including growing a virus somewhere like chicken eggs and transporting and storing the virus,” she says. “Since our work is using only part of a pathogen in a nanoscale delivery device made of a polymer, we can design materials that are more robust without having to worry about the disadvantages of working with live viruses.”

Mallapragada’s work is part of the polymers and materials research going on within the Nanovaccine Initiative at Iowa State. The initiative includes several researchers who are developing nanoparticle platforms that can be used in disease prevention.

“The platform technologies we are creating aren’t necessarily disease specific. It’s a bigger picture plan to improve both the effectiveness and accessibility of vaccines,” Mallapragada adds. One example would be having a team look at using proteins or pieces of pathogens to create a combination vaccine that fights both influenza and pneumonia since those diseases can often occur together.

The projects involve interdisciplinary teams that include researchers and medical professionals both on and off campus. “Immunologists are learning about materials science, and students and post docs in engineering are learning about cell cultures and animal models,” Mallapragada says. “The collaborative environment has allowed us to thrive, and we’re looking forward to seeing these projects eventually head to human clinical trials.”