2000 NSF CAREER winners include three from college
Three COE electrical and computer engineering assistant professors are recipients of the 2000 Faculty Early Career Development Award (CAREER) Award from the National Science Foundation. They are Yogesh Gianchandani, Susan Hagness and Amit Lal. Hagness and Lal are also faculty members in the Department of Biomedical Engineering. NSF established the awards to help scientists and engineers develop simultaneously their contributions to research and education early in their careers.
Yogesh Gianchandani is developing a new class of electrothermal microactuators that promises a100-fold increase in force while requiring one tenth the drive voltage of other thermal actuators. The proposed actuators will leverage deformations caused by localized thermal stresses in order to produce efficiently large forces without compromising displacement. The lack of durable, low-power, high-force actuators is a limiting factor in the development of silicon-based microsystems.
The actuators might be used in a number of applications including a positioner for scanning probe microscopy; a positioner for optical elements in a micro-optomechanical system; and a sliding shunt for high-frequency telecommunication systems.
Eventually, these actuators could be used to develop haptic interfaces, e.g. for simulating microsurgery.
One of Gianchandani's educational objectives is to increase the participation of under-represented groups in the MEMS research community using early recruitment programs and interaction with student groups. Another is to facilitate interdisciplinary education using practical engineering projects. These efforts will be reinforced by interactions with industry.
Susan Hagness will develop highly accurate and efficient computational electromagnetics algorithms for modeling the propagation of light in photonic microstructures. With transmission rates moving into the terabit-per-second regime to meet the ever-increasing demand in fiber-optic communications, there has been much interest generated in micrometer-sized optical devices. Photonic microstructures -- versatile building blocks in future high-density photonic integrated circuits -- may offer unprecedented optical information processing capabilities. First-principles simulation tools will provide a virtual lab bench for exploring the novel linear and nonlinear wave propagation effects that occur on distance scales comparable to the optical wavelength. These numerical tools will also be used to conduct low-cost feasibility studies of new device designs, such as filters or wavelength converters based on linear or nonlinear photonic crystals, and to optimize designs before devices are fabricated. The primary objective of the educational component is to enhance electromagnetics education with innovative teaching approaches in two core undergraduate electromagnetics courses and developing a graduate-level course on methods in computational electromagnetics. Web-based lectures will be developed for student use outside the classroom so that more time inclass may be used for small-group problem-solving sessions. Numerical methods will be incorporated into both undergraduate and graduate-level courses to help students "visualize" electromagnetic field and wave phenomena.
Amit Lal's proposed technology integrates piezoelectric actuation with MEMS (micro electrical mechanical systems). In one example, piezoelectric materials are monolithically bonded to silicon substrates to generate ultrasonic stress pulses incident on surface micromachines. The piezoelectric plate actuators deliver momentum from the bottom of the substrate to surface micromachines, giving three dimensionality to two-dimensional surface micromachines.
The proposal focuses on using the ultrasonic pulse energy to address two challenges in making MEMS more practical. The first is to free stuck surface micromachines to solve an in-use adhesion problem. The second is to actuate hinged surface micromachines to enable massively parallel assembly and actuation.
To explore the ultimate limits of the technology, Lal will develop analytical and numerical models of pulse generation. The models will be used to design electronic circuits and actuator structures that optimize either force or velocity delivered from the substrate. The possibility of actuating MEMS structures without interconnects is a major advantage of this strategy.
Lal is promoting a plan to assimilate MEMS concepts into core microelectronics courses.
He plans to work with non-MEMS faculty to work MEMS fundamentals into department core courses to reach all electrical engineers studying microelectronics. He hopes this massive proliferation of MEMS knowledge in a broad community ultimately will allow industrial design teams to use MEMS devices more readily. In addition, a course in BioMEMS focused on fundamentals of chemistry, biology and fluid mechanics will be developed for electrical engineering students.