MXene-based hydrogels have received significant attention due to several promising properties that distinguish them from conventional hydrogels. In this study, it is shown that both strain and pH level can be exploited to tune the electronic and ionic transport in MXene-based hydrogel (M-hydrogel), which consists of MXene (Ti3C2Tx)-polyacrylic acid/polyvinyl alcohol hydrogel. In particular, the strain applied to the M-hydrogel changes MXene sheet orientation which leads to modulation of ionic transport within the M-hydrogel, due to strain-induced orientation of the surface charge-guided ionic pathway. Simultaneously, the reorientation of MXene sheets under the axial strain increases the electronic resistance of the M-hydrogel due to the loss of the percolative network of conductive MXene sheets during the stretching process. The iontronic characteristics of the M-hydrogel can thus be tuned by strain and pH, which allows using the M-hydrogel as a muscle fatigue sensor during exercise. A fully functional M-hydrogel is developed for real-time measurement of muscle fatigue during exercise and coupled it to a smartphone to provide a portable or wearable digital readout. This concept can be extended to other fields that require accurate analysis of constantly changing physical and chemical conditions, such as physiological changes in the human body.
|Original language||English (US)|
|State||Published - Oct 26 2021|
Bibliographical noteKAUST Repository Item: Exported on 2021-10-28
Acknowledgements: Research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST). The authors thank the Advanced Nanofabrication, Imaging and Characterization Laboratory at KAUST for their excellent support.