Blowing up Ti3C2TX MXene membrane for robust sound detection

Flexible pressure sensors have attracted great attention in health monitoring, human-machine interface, and soft robotics because of their simple device structure and easy to read signals. Two-dimensional (2D) materials (e.g., MXene) are promising candidates for constructing flexible pressure sensors due to their high conductivity and solution-based processability. Typically, during filtration, micrometer-sized MXene nanosheets are assembled into a thin membrane with plenty of wrinkles and folds in order to minimize the total energy. Herein, by taking advantage of this phenomenon, hydrazine hydrate is employed as a foaming agent to blow up the wrinkles and folds of MXene nanosheets in the membrane by gas species generated from the redox reactions, forming a porous foam. The as-prepared pressure sensor shows high sensitivity for a wide linear range (102.89 kPa(-1) for 0-0.5 kPa and 2.86 kPa(-1) for 2-10 kPa), low detection limit (1 Pa), fast response time (132 ms), and excellent durability (over 5000 cycles). As a detector, the MXene sensor can not only identify different sound signals and sound attributes by monitoring the vocal cord vibration but also distinguish various natural sounds transmitted through the air pressure waves caused by the sound transmission.

Automated summary

Flexible pressure sensors are attracting attention in various fields due to their simple structure and easy signal interpretation. MXene, a two-dimensional material, shows promise in constructing these sensors due to its high conductivity and processability. By utilizing the wrinkles and folds in the MXene nanosheet membrane, a porous foam is formed using hydrazine hydrate as a foaming agent. The resulting pressure sensor exhibits high sensitivity, low detection limit, fast response time, and excellent durability.