MXene Functionalized, Highly Breathable and Sensitive Pressure Sensors with Multi‐Layered Porous Structure

Abstract

AbstractBreathable, flexible, and highly sensitive pressure sensors have drawn increasing attention due to their potential in wearable electronics for body‐motion monitoring, human‐machine interfaces, etc. However, current pressure sensors are usually assembled with polymer substrates or encapsulation layers, thus causing discomfort during wearing (i.e., low air/vapor permeability, mechanical mismatch) and restricting their applications. A breathable and flexible pressure sensor is reported with nonwoven fabrics as both the electrode (printed with MXene interdigitated electrode) and sensing (coated with MXene/silver nanowires) layers via a scalable screen‐printing approach. Benefiting from the multi‐layered porous structure, the sensor demonstrates good air permeability with high sensitivity (770.86–1434.89 kPa−1), a wide sensing range (0–100 kPa), fast response/recovery time (70/81 ms), and low detection limit (≈1 Pa). Particularly, this sensor can detect full‐scale human motion (i.e., small‐scale pulse beating and large‐scale walking/running) with high sensitivity, excellent cycling stability, and puncture resistance. Additionally, the sensing layer of the pressure sensor also displays superior sensitivity to humidity changes, which is verified by successfully monitoring human breathing and spoken words while wearing a sensor‐embedded mask. Given the outstanding features, this breathable sensor shows promise in the wearable electronic field for body health monitoring, sports activity detection, and disease diagnosis.