Towards development of a one-port resonant sensor for robotic-based microassembly force measurement

A basic analytical and simulation model of a novel integration of a double-ended tuning fork (DETF) resonant force sensor into a compliant, passive microgripper is presented. The proposed design consists of three main parts: a microgripper, a microlever system, and a one-port, parallel-plat DETF force sensor. A stress relief spring is utilized as a passive temperature compensation method, which reduces the force sensor sensitivity to the ambient temperature change by 86%. DETF sensitivity to a change in the ambient temperature is numerically evaluated. On the other hand, the frequency dependence on forces, less than 120 μN, is also studied. In particular, the sensor is specifically designed to be only sensitive to the normal forces (i.e., microgripping forces) in the microgripper jaw. This condition reduces unnecessary model complexity. However, this approach works for microgripping forces larger than 100 μN. The simplicity of the force sensor, however, provides strong motivation and feasibility for their use in microgripping and microassembly applications.