Modeling of faulty implantable MEMS pressure sensors

Abstract

Implantable biomedical devices generally comprise MEMS-type sensors used to acquire physiological signals, as well as CMOS electronics to perform powering, signal conditioning and data transmission. Among their requirements, reliability over an extended period of time ought to be spotlighted. Thus, modeling and realistic fault injection is essential to improve their long-term results. This work targets the development of a fault model for MEMS capacitive pressure sensors, to be part of smart stents with arterial blockage detection capabilities. The deflection profile of circular and square-shaped diaphragms under fault-free conditions has been analytically modeled. However, analytical models are inaccurate to describe the behavior of diaphragms under faulty conditions, which alter the geometry or material properties of the sensor. In these cases, the use of FE analysis tools is necessary to build a realistic fault model library, together with a comprehensive MEMS testing approach.