Microelectromechanical Sensors And Measurements

Abstract

Microelectromechanical systems (MEMS) are realizing their potential in many areas of pure and applied science. This dissertation presents novel sensor designs and studies toward realization of MEMS in realistic sensor applications. A parallel plate membrane is presented whose small air gaps and megahertz resonance frequency takes advantage of the gas dynamics in squeeze films to produce a pressure sensor, thereby suggesting a means of improving the quality factor (Q) of resonance in fluid. The non-linear frequency dependence to stress in a buckled beam is used to demonstrate a sensitive generic geometry for trace vapor sensing. In the fundamental study of quality factor, the uncharacteristically low dissipation (Q[-]1 ) observed in silicon nitride resonators is shown to relate to film stress, suggesting a means of exploring the otherwise-inscrutable universal dissipation plateau observed in glasses. These studies demonstrate an interesting advance in application and development of MEMS.