A submersible piezoresistive MEMS lateral force sensor for a diagnostic biomechanics platform

A submersible lateral force sensor has been developed as part of an integrated microelectromechanical system (MEMS) on a 4 mm by 4 mm chip for the study of cell biomechanics. The development of an integrated platform that combines both force sensing and actuation in order to determine cell stiffness could provide a useful scientific tool for the search for mechanical biomarkers that are related to disease. The piezoresistive elements in this force sensor are defined in a unique geometry by a single etch step on a silicon-on-insulator (SOI) wafer without the need for a patterned doping step. This fabrication strategy is especially beneficial for integration of multiple MEMS components onto a single SOI platform. Characterization results from fabricated devices are presented, and a fully characterized force sensor is used to measure the reaction force of a single cell during compression.