Graphene/MXene Composite Aerogels Reinforced by Polyimide for Pressure Sensing

Abstract

Here, polyimide (PI) was introduced as a binder and enhancer of graphene oxide (GO) and MXene sheets to prepare robust rGO/MXene/PI (GMP) composite aerogels with good mechanical elasticity, high conductivity, excellent thermal stability, and reliable heat insulation ability. The unique physical and chemical interactions among GO, MXene nanosheets, and the PI precursor enhance the three-dimensional network framework of aerogels. As a sensing material, the GMP aerogel with a layer-strut network structure prepared by directional freezing has a low density (8.97–12.71 mg/cm3), high conductivity (3.08 S/m), significant reversible compression (90%), and excellent fatigue resistance (10,000 cycles). The piezoresistive sensor based on the GMP composite aerogel can quickly detect a tiny strain, which could be further used for pulse beating, breathing, vibration, finger bending, and other human health monitoring. With the assistance of PI, the aerogel also presents high thermal insulation performance (0.022 W/(m·k)) and excellent low-temperature tolerance (−196 °C), showing wide application potential in many fields.