Annularly Grooved Diaphragm Pressure Sensor With Embedded Silicon Nanowires for Low Pressure Application

We present a nanoelectromechanical system piezoresistive pressure sensor with annular grooves on the circular diaphragm where silicon nanowires (SiNWs) are embedded as sensing elements around the edge. In comparison with our previous flat diaphragm pressure sensor, this new diaphragm structure enhances the device sensitivity by 2.5 times under pressure range of 0-120 mmHg. By leveraging SiNWs as piezoresistors, this improvement is even remarkable in contrast to other recently reported piezoresistive pressure sensing devices. In addition, with the miniaturized sensing diaphragm (radius of 100 mu m), the sensor can be potentially used as implantable device for low-pressure sensing applications.