Electrostatically actuated bilayer polyimide-based microresonators

Novel all-polymer resonator microbridges with a structural layer composed of a bilayer of a blended conductive polymer and a polyimide (PI) layer are fabricated on glass substrates using surface micromachining. In this bilayer structure, the conducting polymer layer allows electrostatic actuation, and the second polymer layer is chosen to provide the mechanical properties of the microstructure. The electromechanical properties of the polymer bilayer microbridges are studied using electrostatic actuation and optical detection, and compared to those of a single layer polymer microbridge. The resonance frequency of the polymer bridges occurs in the MHz range, with quality factors ( Q ) of the order of 100 when measured in a vacuum. The effect of the length of the structure, as well as of the pressure and temperature during measurement, on the resonance characteristics of bilayer polymer microbridges is discussed.