A novel computer-assisted design tool for implantable MEMS pressure sensors

Nowadays, implantable biomedical devices generally join together MEMS-based sensors and CMOS electronics in order to perform the measurement and transmission of physiological signals, respectively. This work focuses on the analytical modelling of capacitive MEMS pressure sensors, along with the development of a MEMS design tool, which provides a sensor design proposal based on the fulfilment of a user-specified input constraint set. Two separate folders are generated as outputs by the tool, containing all the files required to perform both electromechanical and electromagnetic analyses of the sensor in Ansys®, as well as to create a sensor layout cell ready to be included in Cadence® designs. Several MEMS capacitive pressure sensors have been fabricated in PolyMUMPS technology with the assistance of the proposed design tool. Sensor responses, with and without injected defects, have been studied in order to quantify the influence of fabrication defects on their capacitance vs. pressure sensitivity.