▎ 摘　　要

The advancement in the applications of wearable and smart devices stimulated the investigation for flexible electronic sensor. However, the efficient operation of these sensors at low temperature is a big challenge due to the inactivation of material microstructure. To address this point, we prepared a piezoresistive pressure sensor based on a three-dimensional porous reduced graphene oxide film with microvoids, which endowed the film's excellent mechanical property, and thus the sensor still kept enough sensitivity at 77 K. At room temperature, the sensitivity of the pressure sensor was 0.009 kPa(-1) (0-10 kPa), and the response time and recovery time were 13 ms and 25 ms, respectively. In liquid nitrogen, the sensitivity of the pressure sensor was 0.05 kPa(-1) (0-5 kPa), and the response time and recovery time are 16 ms and 22 ms, respectively. The sensor showed excellent performances in real-time monitor of breathing, finger bending, frowning, and other human physiological signals. In addition, the sensor is assembled into a 3-pixel array to provide a 3D pressure mapping for various forces under different temperature.