Self-contracting, battery-free triboelectric wound healing strip with strong wet adhesion.

Abstract

Conventional wound closure techniques, such as suturing and stapling, often cause infection, delayed healing, and tissue damage, particularly in fragile or compromised tissues. A sutureless, battery-free adhesive strip (SBF strip) is developed to integrate shape-memory-assisted mechanical approximation with impedance-matched electrical stimulation for enhanced tissue repair. The device incorporates a shape memory polymer (SMP) responsive at near-body temperature and a robust wet-adhesive interface (> 200 J m^-2), enabling rapid attachment and uniform closure under mild heating (40 °C). A built-in ultrasound-driven triboelectric system achieves optimal skin-impedance matching (~50 kΩ), generating electric fields up to 0.59 kV m^-1 under 0.5 W cm^-2 to promote cellular migration and proliferation. Finite element simulations reveal that SMP-induced contraction redistributes local mechanical strain, reducing scarring. In vivo rat studies demonstrate a 61.7% reduction in scar area compared to sutures, along with improved epithelial regeneration, collagen deposition, and angiogenesis. This mechanically and electrically synergistic platform offers a scalable, battery-free wound therapy strategy, reducing dependence on external power and disposable components while enabling precision-guided healing.