The static and dynamic characteristics of micro-electro-mechanical-systems (MEMS) can be influenced through the application of an electrostatic field or thermal gradient. Both of these mechanisms will affect the performance of the MEMS device significantly. The thermal effects manifest themselves by varying the structural characteristics, Young's modulus of elasticity of the waveguide structure, and the material properties. These types of influences will affect the mechanical integrity through an increase in the flexibility leading to variations in the static deflections and also to the dynamic frequency eigenvalues, and changes to the device geometry can lead to faulty measurements where capacitive sensing is employed. Hence, thermal variations in the operating environment can result in unwanted thermal noise and degradation of signal integrity. Electrostatic fields or forces can be used to correct for thermal influences, for example, or as stand-alon microsystem performance tuners. The corrector characteristics can be achieved by the integration of a suspended electrode over the waveguide, for example where the induced electrostatic stiffness is aligned with the mechanical stiffness of the waveguide and are opposite in direction to the thermally induced "softening". The "stand-alone" characteristics of an applied electrostatic field can be used to selectively deflect the waveguide through an applied bias voltage and hence the static and dynamic performance can be trimmed or tuned by the application of an electrostatic field. This paper presents an experimental and theoretical investigation into coupled thermo-electrical influences on a microcantilever structure. These combined influences are typical of the operating characteristics and environments of microsystems currently in use.

Date Published: 11 October 2005
PDF: 12 pages
Proc. SPIE 5970, Photonic Applications in Devices and Communication Systems, 597017 (11 October 2005); doi: 10.1117/12.628601

Published in SPIE Proceedings Vol. 5970:
Photonic Applications in Devices and Communication Systems
Peter Mascher; John C. Cartledge; Andrew Peter Knights; David V. Plant, Editor(s)