Biocompatible, stretchable, and compressible cellulose/MXene hydrogel for strain sensor and electromagnetic interference shielding

With the booming growth of flexible human-computer interactions and telecommunications, it is desirable to fabricate a high-sensitivity strain sensor to monitor human movement and develop an electromagnetic interference (EMI) shielding materials to protect modern microelectronics and humans from electromagnetic damage. Herein, the biocompatible, stretchable, and compressible cellulose/MXene hydrogel has been prepared to first realize the dual-functional applications in strain sensor and EMI shielding. Two-dimensional MXene nanosheets serve as conductive sensing materials and fillers to construct conductive networks. The hydrogen bond interaction between them enhances the mechanical property of hydrogel. Benefiting from the excellent electrical conductivity and good mechanical property of the cellulose/MXene hydrogel, the resultant strain sensor displays excellent tensile strain (~144.4%), high sensitivity (gauge factor ~ -6.97), adjustable detection range (0-68.7%), fast response time (~100 ms), and great stability (~1000 cycles). It can monitor human motion, including pulse beating, speech recognition, writing sensing and pressure distribution induction of 4 × 4 sensor array platform. Moreover, the cellulose/MXene hydrogel presents an absorption-predominant EMI shielding performance in the frequency of X-band. This work provides a new inspiration for the development of multifunctional hydrogel in artificial intelligence, human-computer interaction, and EMI shielding technique.