The piezoresistive behavior of a novel device for the mechanical stress measurement is presented. The sensor consists of ntype, p-type or micro-compensated amorphous silicon thin film with a sensitive area of 300X300 mum(2). It can measure the bending force and torsion force with good electrical properties, as good linearity of its response. Due to low temperature fabrication process the sensor element can be deposited directly on the stressed materials without additional packaging and fixing procedures. These are very interesting properties for its use in advanced robotic systems.