Electrostatically Actuated Nonconductive Polymermicroresonators with Amplified Quality Factor in Gaseous and Aqueous Environment

We present nonconductive microresonators made of SU-8 actuated by the Kelvin polarization force. This technique allows the direct actuation of pure and nonconductive polymer microstructures in gaseous and aqueous environment. Instead of playing the role of the functional layer in a silicon based chemical or biosensor, the sensitive polymer acts as structural material. This method allows the separation of a complete sensing system into the driving circuit and a cheap and disposable, sensitive polymer microresonator array. The relative low quality factor of polymer micro actuators is enhanced by a feedback of the velocity signal. The quality factor was enhanced to an effective quality factor, in water from Q=1 to Q_eff=33 and in air at atmospheric pressure from Q=22 to Q_eff=506.