A novel piezoresistive sensor with rectification properties

Flexible piezoresistive sensors with high sensitivity, low cost, and good durability have been studied for widely use in automatic testing, control technology, and wearable devices. Most piezoresistive sensors can be regarded as varying resistances under different pressures, which do not have current directionality. Here, we report a novel piezoresistive sensor with rectification characteristic by doping reduced graphene oxide (rGO) powder into graphene oxide (GO) film. This piezoresistive sensor exhibits good rectification characteristic for rectifying low-frequency alternating current (AC) signals, coupled with an increase in resistance change rate in response to increased pressure within approximately 24 kPa. When the applied pressure exceeds the threshold, the resistance change rate tends to saturation, reaching up to 99.9 %. The sensor has a high peak sensitivity of 9.65 kPa−1, and a great stability in durability, remaining stable piezoresistive performance under 5500 cycles of pressure test. The piezoresistive sensor also has a fast response time of 72 ms and recovery time of 26 ms. Our work provides a simple way to fabricate a novel piezoresistive sensor with rectification characteristic for next-generation diode and high performance sensor.