Four Yale Engineers Are Honored for Skill at Melding Research and Teaching

From solar energy and mouse brain imaging to robotic assistants and tiny fuel cells that might one day power your iPhone, the research being done by Yale’s engineers today is on the cusp of becoming the technology of the future.

For four researchers in the School of Engineering & Applied Science, achieving that goal is about to get a little easier. Minjoo Larry Lee, Aaron Dollar, Michael Levene and André Taylor have each secured CAREER Awards, the National Science Foundation’s most prestigious honor for junior faculty who excel at integrating research with teaching.

The grants will fund four projects that span different areas of engineering, including electrical, biomedical, mechanical and chemical.

Minjoo Larry Lee

After a rushed proposal that was due only two months after he got his lab group up and running last summer, Lee was thrilled to find out he had won one of the coveted awards. He plans to use it to study the potential of a new semiconductor material to improve the efficiency of current solar cell technology.

With a background in materials science, the assistant professor of electrical engineering will use different layers of semiconductors in an attempt to create a solar cell that absorbs sunlight across a wider part of the spectrum. His project will focus on efficiently converting yellow-green and shorter wavelengths of light into electricity, as opposed to wasted heat.

With most commercially available solar cells today operating at between 10% and 29% efficiency, there’s a lot of room for improvement, notes Lee. He believes it might be possible to achieve up to 60% efficiency with these novel materials, which some analyses have suggested is the tipping point that would allow solar cell technology to become economically viable on large scales.

“What we’re trying to do is make contributions to the technology that will be lasting,” Lee says.

Aaron Dollar

For Dollar, the award will give him the chance to study what most of us take for granted on a daily basis: the ability to grasp and manipulate objects with our hands.

Dollar, who came to Yale from the Massachusetts Institute of Technology last year as an assistant professor of mechanical engineering, is working to design and build flexible robotic hands capable of picking up and manipulating small objects, like pens or coins, as well as powerfully grasping larger objects, such as hammers and cups.

A mechanical hand that can accomplish both kinds of tasks — those requiring “precision manipulation” as well as “power grasping” — has potential applications in prosthetics, which Dollar points out hasn’t changed much in the past 60 years, as well as domestic robotic assistance.

“Most research efforts these days are about pushing robotics to be able to deal with the sorts of unstructured environments that humans tend to find themselves in,” he says.

Michael Levene

While robots and solar cells seem right at home in engineering labs, mice might seem a little out of place. But Levene, an assistant professor of biomedical engineering, straddles the worlds of technology and neuroscience.

Levene uses needle-like lenses to probe and image the cortex of living mice. Traditionally, scientists have only been able to optically image about 5% of the mouse brain, unable to reach the deeper layers of the cortex where interesting brain processes relating to thought, memory and awareness take place.

Now Levene hopes to use the CAREER Award grant to image the other 95% of the mouse brain by improving the optics of his lenses. He’ll also use a prism-lens combination in a way similar to a periscope, allowing him to image cells that haven’t been damaged by the needle. By imaging living mice, these new techniques will allow Levene to see neural activity in real time.

“That kind of knowledge would be useful in a wide range of applications, from the design of better drug delivery systems to understanding the role genes play in diseases affecting the brain, such as Parkinson’s and Alzheimer’s,” Levene says.

André Taylor

Taylor, an assistant professor of chemical engineering, is interested in improving how electronic devices, such as laptops, cell phones and remote sensors, are powered. Using nanomaterials, he looks at ways to improve energy conversion and storage. Until now, the poor performance of micro fuel cells — an alternative to traditional batteries — has kept them from being widely used in these kinds of devices.

With his new grant, Taylor will investigate ways to combine both top-down micro/nanofabrication techniques (the way integrated computer chips are built, using lithography) with bottom-up techniques (synthesis and layer-by-layer assembly) to create a new generation of micro fuel cells. This combined approach will allow Taylor to build the fuel cells in a similar manner to other microelectronic devices, such as resistors and transistors, rather than having to build around them.

“If we can construct our micro fuel cells using high performance nanomaterials with the best nanomanufacturing techniques, we can greatly increase their power output while maintaining the capacity for mass production,” Taylor says.