Fall 2001

ME/IE 8773-8774

Parallel Micro Self-Assembly on Electrochemically Modulated Surfaces

by

Karl F. Böhringer, Ph.D
MEMS Laboratory
Department of Electrical Engineering
University of Washington, Seattle

Wednesday, November 28, 2001
3:30-4:30 p.m.
Room 108 ME
Broadcast on UNITE Channel A
Coffee and cookies will be available in 152 ME following the seminar

In next generation microelectromechanical systems (MEMS), sensors and actuators will be integrated with electronic, optical, and fluidic components onto a variety of substrates to create powerful microsystems. Massively parallel micro self-assembly is an efficient, low-cost alternative to complex, monolithic fabrication processes or robotic pick-and-place micro-assembly. Fluidic self-assembly is driven by hydrophobic-hydrophilic surface patterning and capillary forces. We demonstrate a method for multi-batch parallel micro-assembly via electrochemical modulation of the surface hydrophobicity. In each assembly step, micro-parts can be assembled onto selectively activated hydrophobic sites. The ability to repeatedly apply this technique allows different batches of micro-components to be organized onto the same substrate. Micro self-assembly relies on energy minimization as its driving force, and proceeds completely open-loop. This gives rise to a multitude of challenges in system design and modeling. We present recent experimental results and discuss a simple, efficient computational model to predict the behavior of self-assembly systems and to optimize the shape of binding sites.

Karl Böhringer is currently an assistant professor in Electrical Engineering and an adjunct assistant professor in Computer Science & Engineering at the University of Washington, Seattle. He received both his M.S. and Ph.D. degrees in Computer Science from Cornell University and his Diplom-Informatiker degree from the University of Karlsruhe, Germany. During his dissertation work on distributed micromanipulation he designed, built, and tested multiple micro actuator arrays at the Cornell Nanofabrication Facility. He also spent a year as a visiting scholar at the Stanford Robotics Lab and Transducer Lab where he collaborated on research in MEMS distributed cilia arrays. From 1996 to 1998 he investigated techniques for parallel micro self-assembly at the University of California, Berkeley. His current interests as a member of include microelectromechanical systems (MEMS), micromanipulation and microassembly, and integrated biologically active microsystems. His Ph.D. thesis was nominated for the ACM doctoral dissertation award. He received an NSF postdoctoral associateship in 1997 and an NSF CAREER award in 1999.

Informal Faculty Luncheon: Wednesday, November 28, 2001, 12:00 noon. Prof. Böhringer will be able to attend.