Title :
Polysilicon microstructures to characterize static friction
Author :
Lim, M. ; Chang, J. ; Schultz, D. ; Howe, R. ; White, R.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of California, Berkeley, CA, USA
Abstract :
The design, fabrication process, and initial experiment results for a test microstructure for measuring static friction are described. A normal force is applied to a displaced suspended structure by an underlying electrode. The tangential force to measure the frictional force is produced by a restoring force from the displaced suspension. The spring constant is found empirically by resonating the structure. The μ for coarse-grained polysilicon-polysilicon interfaces is found to be 4.9±1.0. Silicon nitride-polysilicon surfaces exhibit less friction with a μ of 2.5±0.5. Friction is found to be independent of apparent area. Tests were conducted on a piezoelectric crystal resulting in a reduction of friction and improved reliability of data extraction
Keywords :
friction; materials testing; silicon; silicon compounds; Si-Si; Si3N4-Si; apparent area; coarse-grained polysilicon-polysilicon interfaces; displaced suspended structure; fabrication process; frictional force; normal force; piezoelectric crystal; restoring force; spring constant; static friction; tangential force; test microstructure; Displacement measurement; Electrodes; Fabrication; Force measurement; Friction; Microstructure; Process design; Silicon; Springs; Testing;
Conference_Titel :
Micro Electro Mechanical Systems, 1990. Proceedings, An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots. IEEE
Conference_Location :
Napa Valley, CA
DOI :
10.1109/MEMSYS.1990.110254
