Interdisciplinary
Research

Faculty Spotlights

Kenji Uchino

Professor Kenji Uchino brings an interesting perspective to research, having at various times in his career been a professor in physics, mechanical engineering, materials and now electrical engineering. Over his career his research interests have spanned an amazing range of phenomena and applications. He has filed 80 patents for his research, most in the area of transducers - materials that convert one type of energy to another.

Uchino originally came to Penn State as a Visiting Research Associate in 1978 from his native Japan. His background in materials meshed perfectly with the research interests of Professors Eric Cross and Bob Newnham at the Materials Research Laboratory. Uchino had been part of a group at Tokyo Institute of Technology that had serendipitously discovered a new class of ferroelectric materials. These materials were based on solid solutions of perovskites Pb(Mg,Nb)O3 and Pb(Zn,Nb)O3. The materials - accidentally produced from cross-contaminated powders in the lab - contained Mg2+ and Nb5+ cations rather than the typical Ti4+ in PbTiO3. The net result was that these materials, termed relaxor ferroelectrics, displayed properties different from existing ferroelectric materials; that is, the electric field induced strain was enormously large. His group also discovered that the electromechanical coupling factor (a measure of transducer's ability to convert electrical energy into mechanical energy) of these new materials approached 95%. Because existing materials at the time had electromechanical coupling factors approaching 70%, other researchers did not initially believe their claims. This high electromechanical transduction rate made relaxor ferroelectrics ideal candidate materials for use in a variety of actuator applications including ultrasonic imaging.

From this early work in relaxor ferroelectrics, Prof. Uchino's research has broadened to encompass photostrictive materials (transducers that convert light energy directly into mechanical motion), shape memory ceramic materials and, most recently, tiny piezoelectric motors with an eye toward the immense medical devices and consumer electronics markets. The heart of a typical motor is two small piezoelectric chips mounted orthogonally on a metal cylinder. By rapidly applying alternating fields to each chip the metal cylinder rotates. His millimeter-sized motors may eventually take over the sub-centimeter regime, where traditional electromagnetic motors become inefficient. At just over 7 mm in length (pictured below), he has produced the world's smallest four-wheel drive vehicle. One near term possibility for his motors is to replace the bulky, inefficient motors in cell phones that vibrate to silently warn of an incoming call.

Unlike many professors focused on basic research, Uchino's research has always been driven by a desire to produce practical commercial products. He is in constant contact with more than a dozen companies to keep abreast of their future requirements in the actuator markets. This insight helps him not only know what technical specifications his creations must meet but, equally as importantly to him and his industrial collaborators, what the maximum unit cost can be.

For more information about Professor Uchino visit his web site at http://www.mri.psu.edu/centers/icat/ or better yet make an appointment to visit his lab and observe his tiny machines in motion.