Soft materials can mimic a salient feature of life: movements in response to stimuli. For example, an electric field can cause an elastomer to stretch several times its length. As another example, a change in pH can cause a gel to swell many times its volume. These soft active materials are being developed for diverse applications, including soft robots, adaptive optics, self-regulated fluidics, and programmable haptic surfaces. This talk describes recent work in my group on the mechanics of soft active materials. We formulate theories to answer commonly asked questions. How do mechanics, chemistry, and electricity work together to generate large deformation? What is the maximal energy that can be converted by a soft material? How do molecular processes affect material response? The theories are illustrated with phenomena arising in applications, drawing on recently reported experimental observations, and focusing on large deformation and instability.

Zhigang Suo is the Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials at Harvard University. He earned a bachelor degree in Engineering Mechanics from Xi'an Jiaotong University in 1985. Upon earning a Ph.D. degree in Engineering Science from Harvard University in 1989, Suo joined the faculty of the University of California at Santa Barbara and established a group studying the mechanics of materials and structures. The group moved to Princeton University in 1997 and to Harvard University in 2003. His research centers on the mechanical behavior of materials and structures. Basic processes include fracture, deformation, polarization, and diffusion, driven by various thermodynamic forces (e.g., stress, electric field, electron wind, chemical potential). With Teng Li, Suo co-founded iMechanica, the web of mechanics and mechanicians which now has over 15,500 registered users. He is a member of the Executive Committee of the Applied Mechanics Division (2005-2010), of the American Society of Mechanical Engineers (ASME), and is a member at large of the US National Committee on Theoretical and Applied Mechanics (2006-2010). Suo is a recipient of the Humboldt Research Award. He won the Pi Tau Sigma Gold Medal and the Special Achievement Award for Young Investigators in Applied Mechanics, both from ASME. He was elected as a member of the US National Academy of Engineering in 2008 for “fundamental and applied contributions to the thermo-mechanical performance of electronic materials systems, actuator materials, and composites.”

For more information, e-mail dsantoni@jhu.edu.