Impact of design parameters on actuation voltage and response time for micro-cantilever based device

Microcantilveres are important micomachined components used in many applications. Modeling, simulation and fabrication of a microcantilever designed to achieve less actuation voltage and response time for electrostatically actuated microcantilever based device is presented in this paper. The effects of various design parameters and materials on sensitivity and response time of the microcantilever is investigated. The sensitivity of a microcantilever beam is studied by varying physical parameters of cantilever such as length, width and thickness. Results indicate that for a fixed displacement of 1um between top beam and bottom electrode, increasing microcantilever beam thickness increased the actuation voltage on the other hand an increase in the length of the microcantilever decreases the actuation voltage. Simulations were also done to study the effects of varying physical properties such as length and thickness on response time. It was observed that length and thickness of beam tends to be the most influencing parameters for actuation voltage and response time, which needs to be tightly controlled. Polysilicon microcantilever is fabricated with surface micromachining technology. The simulated values of pull in voltage and response time are experimentally validated on the fabricated device. A comparison between simulation and experimental results for response time showed close agreement.