Studies on the stress dependence of flexible integrated capacitive pressure sensors for minimally invasive biomedicai applications

This publication presents studies on the influence of mechanical stress on the pressure output signal of thinned and by this flexible capacitive monolithically integrated pressure sensors. Mechanical stress arises when integrating the sensors into biomedical implants. A flexible and miniaturized sensor enables the positioning of the implant with minimal interference to the patient during implantation and to the pressure signals at the implantation site. First simulations and four point bending measurements with flexible unstructured silicon chips are conducted in preparation to the simulations and the pressure sensor measurements. Then the dependence of the pressure sensor signal on different chip thicknesses and bending radii at different pressures is examined. These measurements are compared to simulation results.