Inspired by the microstructure of gecko toes, a drivable bionic gecko toe adhesion surface with double-layer structure was designed and fabricated. The driving ability is derived from the volume shrinkage of the dehydrated hydrogel after the driving hydrogel layer is irradiated by near-infrared light (808 nm) (the temperature of the single-layer hydrogel can be increased from 17.9 °C to 107 °C within 30s, and the curling angle can be curled by 0°–180°, similar to the folded state.), and another layer with a microstructure similar to gecko toes can withstand a maximum shear force of 22.4N/cm −2 . The different properties of the two layers are combined together to achieve a reversible transition of adhesion/desorption similar to the gecko walking process. The double-layer structure of the drivable bionic gecko toe adhesion surface was structurally optimized to prepare a four-arm gripper that could grasp/release only by unilateral irradiation. This bilayer-structured bionic gecko toe adhesion surface has great design potential, and in the future, it is hoped that it can provide insights into the preparation of large-actuated remote-controlled robots and fast-actuated soft robots .
Lei Zhou,Cong Dai,Lei Fan,Yuhe Jiang,Can Liu,Zhengnan Zhou,Pengfei Guan,Yu Tian,Jun Xing,Xiaojun Li,Yian Luo,Peng Yu,Chengyun Ning,Guoxin Tan
Biocompatible hydrogel adhesives with multifunctional properties, including injectability, fast self-healing, and suitable on-demand detachment, are highly desired for minimally invasive procedures, but such materials are still lacking. Herein, an injectable self-healing biocompatible hydrogel adhesive with thermoresponsive reversible adhesion based on two extracellular matrix-derived biopolymers, gelatin and chondroitin sulfate, is developed to be used as a surgical adhesive for sealing or reconnecting ruptured tissues. The resulting hydrogels present good self-healing and can be conveniently injected through needles. The strong tissue adhesion at physiological temperatures originates from the Schiff base and hydrogen bonding interactions between the hydrogel and tissue that can be weakened at low temperatures, thereby easily detaching the hydrogel from the tissue in the gelation state. In vivo and ex vivo rat model show that the adhesives can effectively seal bleeding wounds and fluid leakages in the absence of sutures or staples. Specifically, a proof of concept experiment in a damaged rat liver model demonstrates the ability of the adhesives to act as a suitable laparoscopic sealant for laparoscopic surgery. Overall, the adhesive has several advantages, including low cost and ease of production and application that make it an exceptional multifunctional tissue adhesive/sealant, effective in minimally invasive surgical applications.
危险品化学品经营许可证（带存储）