▎ 摘　　要

Recently, macroporous graphene monoliths (MGMs), with ultralow density and good electrical conductivity, have been considered as excellent pressure sensors due to their excellent elasticity with a rapid rate of recovery. However, MGMs can only exhibit good sensitivity when the strain is higher than 20%, which is undesirable for touch-type pressure sensors, such as artificial skin. Here, an innovative method for the fabrication of freestanding flexible graphene film with bubbles decorated on honeycomb-like network is demonstrated. Due to the switching effect depended on "point-to-point" and "point-to-face" contact modes, the graphene pressure sensor has an ultra-high sensitivity of 161.6 kPa(-1) at a strain less than 4%, several hundred times higher than most previously reported pressure sensors. Moreover, the graphene pressure sensor can monitor human motions such as finger bending and pulse with a very low operating voltage of 10 mV, which is sufficiently low to allow for powering by energy-harvesting devices, such as triboelectric generators. Therefore, the high sensitivity, low operating voltage, long cycling life, and large-scale fabrication of the pressure sensors make it a promising candidate for manufacturing low-cost artificial skin.