Dr. Yoseph Bar-Cohen is a senior research scientist and a supervisor of the Advanced Technologies Group at the Jet Propulsion Laboratory, Pasadena, California. He received his PhD in physics (1979) from the Hebrew University, Jerusalem, Israel. Dr. Bar-Cohen discovered the ultrasonic wave phenomena polar backscattering (1979) and leaky lamb waves (1983) in composite materials. In his Nondestructive Evaluation and Advanced Actuators (NDEAA) lab, he led the development of novel methods and mechanisms related to electromechanics that are actuated by electroactive materials as well as ultrasonic nondestructive evaluation methods. Dr. Bar-Cohen initiated the SPIE conference on artificial muscles, which he has chaired since 1999. He challenged engineers and scientists worldwide to develop a robotic arm driven by artificial muscles to wrestle with humans and win, and organized the first arm-wrestling contest in 2005. For his contributions to the field of artificial muscles, Business Week named him one of five technology gurus who are "Pushing Tech's Boundaries" (April 2003). His accomplishments have earned him two NASA Honor Award Medals and two SPIE's Lifetime Achievement Awards, among many other honors and awards. For more information about Dr. Bar-Cohen and his work at the Jet Propulsion Laboratory, see Dr. Bar-Cohen's website.