UNLV faculty member Woosoon Yim recently received the university’s most prestigious research honor, the Harry Reid Silver State Research Award, which was created in 2001 as a tribute to the U.S. senator for his support of UNLV. The award, which recognizes research that is both highly regarded and responsive to the needs of the community and state, provides recipients with a $10,000 stipend funded with private donations from the UNLV Foundation.
Woosoon Yim
Professor of Mechanical Engineering
Woosoon Yim is at home exploring the world around him and probing the properties of materials.
But ask him about the source of his inspiration or how he first became interested in engineering, and that will take a little time. He’d rather talk about the future – and his research on robotic fish.
Robotic fish? Yes, he has developed an undulating, eel-like device, powered remotely, that has some surprising – and very useful – applications.
Yim, who won the 2011 Harry Reid Silver State Research Award, is exploring biomedical applications for his research. It was for this type of creative and innovative work that he received the campus’s most prestigious research honor.
“I always wanted to receive the Silver State Research Award, but didn’t think I could get it,” says Yim, who hoped his National Science Foundation funding would help his case.
The long road to the Silver State Research Award began years ago when a colleague from another university introduced Yim to an electroactive polymer (EAP) that changes shape when electrically stimulated. Yim, who was fascinated with robotics, immediately saw an application for the polymer.
Electroactive polymers are a class of soft actuators that change shape when subjected to electrical stimulation. (An actuator is a type of motor for moving or controlling a mechanism or system.) Yim thought to employ the EAPs to develop small-scale robots that mimic the movement of swimming creatures.
The EAPs were a good fit for this application, as their smooth, wave-like motion recreates eel-like movement. Yim used the EAPs to create a robot that could be used to propel tiny vehicles through fluids.
Yim was awarded his first NSF grant in 2003 for this research; the second grant, awarded in 2007, helped him develop a microwave-based power supply for the EAPs to create a wireless link between the remote mobile units and a power source. This provided a continuous power supply to the robotic units, eliminating the need for the heavy battery and complex internal wiring typically needed for bioinspired robots. It also makes the mobile units more adaptable, as they can use different types of locomotion in response to changing environments.
Yet, the novelty of a fish-like robot alone wasn’t enough to hold Yim’s interest. He recently began work on his third NSF grant, which involves developing a robotic catheter for medical uses; it will be designed to employ the EAPs as a source of movement through the fluid in lumen (tubular tissue, such as intestine or blood vessels) inside the human body.
Catheters need a source of energy for their movement, and this EAP device would provide it. Because the catheter can sense human tissue, there is little risk of the robotic device puncturing lumen during catherization procedures through complex, small passages of the body.
Though the catheter idea is still in the conceptual stage, Yim and his team are seeking an application where it will work more effectively than a traditional catheter. They are currently working on the prototype, and then it must be tested. If it’s successful, it may one day improve the efficiency and safety of catheterizations and could even spawn commercialization opportunities.
According to Mohamed Trabia, the associate dean of the engineering college, Yim’s research has been instrumental in providing insight into the modeling and control of electroactive polymers.
“His work in this area elegantly combines abstract concepts and uses them to address many practical problems,” Trabia says, noting that it has been cited by many of the leading researchers within and outside the U.S. in his field.
Yim’s enthusiasm for robotics grows out of his belief that they will eventually come to play even more important roles in our lives than they already do; he sees them as freeing us from laborious, repetitive activities so that human beings can spend more time developing their creativity.
Yim received his bachelor of science degree in mechanical engineering at Hanyang University, Seoul, Korea in 1981. Just after his undergraduate study, he went on to the University of Wisconsin-Madison for his master’s degree and Ph.D. in mechanical engineering. It was his dissertation research, tracking moving objects in 3-D space, that sparked his interest in robotics.
After receiving his doctorate, he headed west and joined the UNLV faculty in 1987 as an assistant professor in the department of mechanical engineering.
“I figured I would get work experience before going back to Korea – and now it is 24 years later!” he says.
From the late 1980s through the early 1990s, his research involved a robotic arm with a flexible link. This arm, lightweight and elongated, was used for repair work outside the space shuttle.
“If you make the arm long, you make it flexible; also, there is less material in the arm,” he says, adding that the drawback of a long, flexible arm is that it’s subject to shaking. His research involved mitigating the shaking and vibration of this flexible arm to obtain better performance.
In addition to receiving the Silver State Award this past year, Yim became a Fellow of the American Society of Mechanical Engineers (ASME) in 2010; he received the Eminent Engineer Award in 2009 from Tau Beta Pi, the Engineering Honor Society. At UNLV, he was honored with the Outstanding Faculty Award in the department of mechanical engineering in 2005 and the department’s Teacher of the Year award in 2000.
This coming year Yim, who also serves as chair of his department, will continue his work on the NSF grant; his team is already planning their proposal for the next phase of development. He is grateful for the opportunity his grants have provided him.
“These monies allow faculty the time and space needed to experiment and to imagine,” he says, noting that his research wouldn’t have happened without time for imagination.
Julie Longo contributed to this article.
