Piezoresistive ring-shaped MEMS resonator

We have previously reported a new class of MEMS resonators based on the piezoresistive readout principle and extensional vibration mode. Those devices suffer from unwanted mode-coupling at large vibration amplitudes, giving rise to problems such as beat patterns in the time signal. In this paper, we present a novel type of piezoresistive resonator that has a shape of a ring and operates in a flexural in-plane mode shape. The new resonators can be operated at larger excitation forces without having the mode-coupling problem, as compared to the conventional piezoresistive resonators.