Construction of a new flat force sensor using the resonant frequency shift by axial force

A new structure of flat force sensors using the resonant frequency shift of a flexurally vibrating bar by the axial force is proposed in this paper. The sensor structure is composed of only one flexurally vibrating bar called a central arm and two short arms flatly arranged on both sides at both ends. As the displacements at the base ends can be extremely reduced by balancing these arms, the structure is not affected by a support. The dimensions of the force sensor are determined by the finite-element analysis when using the out-of-plane modes.. The resonant frequency changes with application of the axial force to the both base ends. The rate of chan-e for the first mode is larger than that for the second mode. This structure is suitable for mass production, and therefore will be expected as a low-cost force sensor with high stability and sensitivity.