▎ 摘　　要

Graphene sponge (GS) with microscale size, high mechanical elasticity and electrical conductivity has attracted great interest as a sensing material for piezoresistive pressure sensor. However, GS offering a lower limit of pressure detection with high gauge factor, which is closely dependent on the mechanical and electrical properties and determined by the fabrication process, is still demanded. Here, gamma-ray irradiation reduced GS is reported to possess a gauge factor of 1.03 kPa(-1) with pressure detection limit of 10 Pa and high stress retention of 76% after 800 cycles of compressing/relaxation at strain of 50%. Compared with the carbon nanotube (CNT) reinforced GS, the improved lower limit of pressure detection and gauge factor of the GS prepared by gamma-ray irradiation is due to the low compression stress (0.9 kPa at stain of 50%). These excellent physical properties of the GS are ascribed to the mild, residual free, and controllable reduction process offered by gamma-ray irradiation.