Bioinspired liquid metal-spidroin (LMS) stripe microneedle actuators

Intelligent wound dressings have demonstrated significant clinical value. Among which flexible actuators dressings hold promise for real-time monitoring and on-demand treatment adjustment. Herein, we develop a novel bioinspired liquid metal-spidroin (LMS) stripe microneedle (MN) actuators for multifunctional wound management. The LMS system consists of recombinant spider silk proteins (spidroin) matrices embedded with gallium-based liquid metal droplets and patterned into asymmetric microneedle stripes by casting and programmed cutting. Benefiting from selaginella-inspired layouts, LMS composites exhibit near-infrared-triggered bending and coiling, while morphology-encoded microchannels guide interstitial fluid along predefined routes without external pumps. The liquid metal core also functions as a deformable electrode and triboelectric nanogenerator, enabling energy harvesting and self-sensing during microneedle deformation. In vitro and in vivo experiments demonstrate that epidermal growth factor-loaded LMS microneedle bandages conformally wrap cutaneous defects and significantly accelerate wound closure and re-epithelialization compared with control dressings. Histological analysis reveals no evident systemic toxicity, indicating acceptable biosafety. These findings suggest that LMS stripe microneedle actuators provide a promising platform for next-generation intelligent wound dressings.