Single Crystal Silicon Actuator Arrays
Massively Parallel Micro Manipulation (1992-1996)
Karl F. Böhringer, Bruce Donald, Noel MacDonald, Robert Mihailovich
The design of our actuators is based on microfabricated torsional resonators.
They consist of rectangular grids suspended by two rods that act as torsional
springs. They are fabricated in a SCREAM process (Single Crystal Silicon
Reactive Etching And Metallization). When an AC voltage is applied between
the grid and adjacent electrodes, the grid oscillates at resonance frequencies
in the high kHz range. The edges of the grid reach deflections of several
micrometers out of the substrate plane.
By introducing asymmetries into the resonator grid (such as placing the
torsional rods off the center of the grid, or adding poles on one side
of the grid) anisotropic lateral forces are generated, thus achieving
a motion bias for the object on top of the actuator.
Each actuator can generate motion in one specific direction if it is
activated; otherwise it acts as a passive frictional contact. The combination
and selective activation of several actuators with different motion bias
allows us to generate various motions in the plane. The figure shows such
a motion pixel.
|Figure 1: Small section of a SCS
micro actuator array.
||Figure 2: Actuator grid with 5 µm
||Figure 3: Micro motion pixel
with 4 actuators.
- K. F. Böhringer, B. R. Donald, N. C. MacDonald, "Programmable
Vector Fields for Distributed Manipulation, with Applications to MEMS
Actuator Arrays and Vibratory Parts Feeders." International Journal
of Robotics Research, 18(2):168-200, February 1999. Paper.
- Karl F. Böhringer, Bruce R. Donald, Noel C. MacDonald, "Single-Crystal
Silicon Actuator Arrays for Micro Manipulation Tasks." IEEE Workshop
on Micro Electro Mechanical Systems (MEMS), pp. 7-12, San Diego,
California, February 11-15, 1996. Paper.
- Karl F. Böhringer, Bruce R. Donald, Robert Mihailovich, and Noel
C. MacDonald, "A Theory of Manipulation and Control for Microfabricated
Actuator Arrays." IEEE Workshop on Micro Electro Mechanical Systems
(MEMS), p. 102-107, Oiso, Japan, January 25-28, 1994. Paper.
A complete list of our publications
(many of them available online) can be found here.
- NSF IRI-8802390, IRI-9000532, IRI-9201699, IRI-9530785, and CISE/CDA
98-05548 IRI-9896020, and by a Presidential Young Investigator award
to Bruce Donald, NSF/ARPA SGER IRI- 9403903
- AFOSR, the Mathematical Sciences Institute, Intel Corporation, and
AT&T Bell Laboratories
- ARPA under contract DABT 63-69-C-0019
© Karl F. Böhringer, Department of Electrical Engineering, Box
352500, Seattle, WA 98195-2500, USA