Wide-range linear piezoresistive pressure sensing synergistically enabled by black phosphorus/MXene van der Waals heterostructure and corrugated structure

Flexible pressure sensors hold significant promise for wearable health/sports monitoring, object recognition and human–machine interactions (HMIs). However, the balancing between sensitivity and sensing range remains a challenge. Sustaining high sensitivity throughout a wide range poses great difficulties, and perfectly linear response output is difficult to realize accordingly. Herein, we propose a flexible piezoresistive sensor with van der Waals-assembled metal (MXene)–semiconductor (black phosphorus, BP) heterostructure (vdWMSHs) supported on corrugated paper. Benefiting from its vdWMSHs and corrugated structure, the sensing layer showcases typical tunneling behavior among heterostructure, undergoes large-scale hierarchical deformation and maintains progressively evolution of interfacial contacts when subjected to external applied loads. Therefore, the sensor achieves a superior linear response (R²=0.995) with a high sensitivity of 4.43 kPa^–1 within a wide range of 2.9–287.5 kPa, as well as fast response and recovery times of 6/33 ms. And the sensor reveals a consistent sensing performance over 11000 loading-unloading cycles under the pressure of 49 kPa. This outstanding performance boosts diverse in real–time monitoring of human motions across a broad pressure range, as well as the mapping of spatial pressure recorded by sensor arrays. This work provides an opportunity to resolving the longstanding challenge in linear response output over a wide detection range, and holds a promising application in e-skin, and health monitoring technologies of the piezoresistive sensors.