3-D Isotropic Tactile Microprobe Based on a Silicon Parallelogram Kinematic: From Concept to Fabrication

This paper reports on a unique tactile microprobe based on a parallelogram kinematic made from monocrystalline silicon. This kinematic, made out of an orthogonal cascade assembly of three identical parallelograms, provides an isotropic behavior to the microprobe. Each parallelogram deflects in only one direction thanks to thin elastic silicon membrane hinges and their displacements are recognized using piezoresistors integrated into these hinges. Wide deflection ranges, isotropic behavior, and low mechanical stiffness of the new microprobe, as predicted by simulations, could be verified in experiments. The fabrication, the assembly, and the contacting of the first microprobe prototype was optimized to allow very compact integration into a Ø11 mm housing. This make it suitable for metrology research laboratories and industries equipped with conventional coordinate measurement machines and even for a variety of other 3-D force/displacement measurements. [2018-0157]