On the optimization of compliant force amplifier mechanisms for surface micromachined resonant accelerometers

The present work deals with the optimization of a compliant force amplifier mechanism in a surface micromachined resonant accelerometer. Figures of merit including noise floor and scale factor are critically dependent on the gain of the force amplifier mechanism, and hence optimization of the force amplifier mechanism is necessary. The optimization is constrained by limitations imposed by the manufacturing process and the device geometry. The force amplifier mechanisms in this work are initially designed using continuum topology optimization. The results of topology optimization are seen to depend strongly on the size of the design space, output and input stiffnesses and boundary conditions. The results of the topology optimization are converted to beam element models that are used for a further shape and size optimization. Single-stage force amplification factors greater than 100 are obtained from the results of the optimization process.