Bio-inspired adhesion enhanced MXene-decorated fabric for strain sensing performance in human fitness exercise monitoring

Flexible fabric strain sensors based on MXene hold huge potential for wearable human motion monitoring; however, their practical application is severely hindered by the poor oxidation stability of MXene and weak interfacial adhesion between the conductive coating and elastic fabric substrates. Herein, we developed a bio-inspired dual-enhancement strategy to construct a robust bio-inspired MXene-based adhesive composite coated fabric (BMAC-fabric) for high-performance fitness exercise monitoring. Inspired by the adhesive nature of snail slime and the interlocked micro/nano-structures of tree frog toe pads, a functional copolymer (HE-co-SV) containing hydroxyl and sulfonate groups was selected as an interfacial binder. This HE-co-SV not only formed the ionic hydrogen bonds, electrostatic anchoring, and widespread van der Waals interactions with the fiber to significantly enhance the adhesion strength between MXene nanosheets and the super-elastic fabric skeleton but also provided intrinsic antioxidant protection to the conductive MXene network. Consequently, the as-prepared BMAC-fabric sensor exhibited greatly enhanced sensing performance compared to traditional MXene-coated fabric, including a wider strain sensing range (0–150%), a lower detection limit (2% strain) and fast response/recovery time (120/180 ms). In addition, it achieved remarkable oxidation resistance and mechanical durability, maintaining stable surface resistance after 72 h of UV irradiation and 2000 cyclic stretching. Benefiting from these merits, the BMAC-fabric sensor enabled accurate and real-time monitoring of both joints bending (large deformation) and muscles contraction (subtle deformation) behaviors. This work presents a promising biomimetic approach for developing durable and sensitive fabric-based electronics, paving the way for next-generation personalized fitness training and humanoid robot interaction.