Synergistic Resistance Modulation toward Ultrahighly Sensitive Piezoresistive Pressure Sensors

Abstract

Improvement of sensitivity of electrical piezoresistive sensors is critical for high-precision and ultrasensitive detection, which mainly depends on the modulation ability of total resistance of sensor under applied pressure. However, in most of the reported sensor devices, the contact resistance and body resistance (the key parts of total resistance of sensor) generally cannot be modulated simultaneously, which results in the limited sensitivity. In this work, an ultrahighly sensitive piezoresistive pressure sensor with an exquisitely designed structure is demonstrated, providing an uncomparable advantage of synergistic modulation of contact resistance and body resistance under applied pressure. As a result, the sensor shows excellent sensing performance, with the highest sensitivity up to 11 668.6 kPa−1, the detection limit as low as 0.425 Pa, and the great stability over 20 000 cycle measurements. In respect of practical application, the high sensitivity endows the sensor with high-precision recognition ability for detecting the weak pressure signals such as sound wave of ringtone and fluctuation of breath or pulse. These results suggest the synergistic resistance modulation to be an effective method toward piezoresistive pressure sensors with ultrahigh sensitivity and offer a new strategy for the achievement of high-performance pressure sensors.