Nanocellulose intercalation to boost the performance of MXene pressure sensor for human interactive monitoring

The advent of smart and wearable electronics endows flexible pressure sensors with promising potentiality. Ti3C2Tx-based MXene is considered as one of attractive sensing materials for its metallic conductivity and adjustable interlayer. However, existing flexible MXene pressure sensor still requires a technical breakthrough that simultaneously possessing high sensitivity, fast response, and durability in low-pressure regime and excellent mechanical strength. Herein, a Ti3C2Tx-based pressure sensor with distinctly enhanced sensing functionality and mechanical strength is demonstrated though inserting high-strength of bacterial cellulose nanofibers to control the interlayer of MXene. By optimizing the bacterial cellulose content and MXene interlayer space, the resultant sensor device exhibits high mechanical strength (225 MPa), wide-sensing range with low detective limit (0.4 Pa), high sensitivity (up to 95.2 kPa−1, in < 50 Pa region), fast response (95 ms) and outperformed repeatability (25,000 cycles), as well as low operation voltage of 0.1 V. For practical application demos, the sensor can monitor multiple human biologic activities, including subtle pressures (e.g., swallow, heartbeat and pulse), acoustic vibrations and gesture motions, and serve as electronic skin for mapping pressure distribution, elucidating the potential application in medical diagnosis, smart robotics and human-machine interfacing.