Water-responsive Contraction for Shape-adaptive Bioelectronics

Water-responsive adaptive contraction represents a pivotal advancement in bioelectronics, offering unparalleled advantages over traditional swollen hydrogels and actuator-based systems. This review explores mechanisms including phase transition, hydrogen bond disruption, and hierarchical hybridization to enable rapid and substantial shape adaptability upon moisture exposure without external control and highlights various component modulation and porous and heterostructure engineering strategies to provide directional control and multifunctionality. Additionally, recent advances in supercontractile films, achieved through cold-drawing processes that disrupt hydrogen bonds in aligned polymer chains are overviewed for wearable and implantable biomedical applications where seamless tissue interfacing is essential. These advances address long-standing challenges in device integration with biological tissues, such as rigidity and inflammation, by creating electrodes that naturally conform to tissue shapes. This review delves into water-responsive adaptive contraction in bioelectronics, emphasizing its potential to revolutionize medical implants, wearable health monitors, and soft robotics by naturally conforming to tissue shapes upon moisture exposure. They promise significant improvements in chronic electronic integration and patient care, paving the way for next-generation medical devices, soft robotics, and smart textiles that adapt dynamically to biological environments.