Standard CMOS piezoresistive sensor to quantify heart cell contractile forces

A MEMS force transducer system, with a volume less than one cubic millimeter, is being developed to measure forces generated by living, isolated cardiac muscle cells. Cell attachment and measurement of contractile forces have been demonstrated with prototype hinged polysilicon devices. A new transducer system has been fabricated using a standard CMOS process with a post-processing XeF/sub 2/ etch step. The system consists of a three dimensional oxide structure with aluminum hinges, polysilicon piezoresistive sensor, and CMOS amplifier. System response is 0.45 mV//spl mu/N. This MEMS force transducer will permit improved resolution of the mechanisms of muscle contraction.