Variable response of a thermally tuned MEMS pressure sensor

A typical microelectromechanical systems (MEMS) pressure sensor consists of a thin, deformable membrane and sensing element such as a piezoresistive element which is used to measure the amount of deflection in response to an applied pressure. Previous efforts demonstrated that buckled membranes, from silicon on insulator (SOI) wafers, can be thermally tuned via joule heating. By applying heat to the membrane through a resistive heating element, compressive stress is induced in the membrane causing it to buckle further out of plane and increasing its overall stiffness response. It is demonstrated that by increasing the stiffness of the membrane, the response to an increase in pressure can be varied and its overall sensitivity to pressure can be reduced by up to 62%.