Lignin Powered Versatile Bioelastomer: A Universal Medium for Smart Photothermal Conversion

Abstract Photothermal elastomers are recognized as smart flexible materials that can rapidly and effectively convert light energy into heat energy. However, there has been a lack of adequate focus on tackling the sustainability challenges of photothermal elastomers, particularly in terms of material selection, the integration of complex functionalities, and final disposal. A fully bio‐derived photothermal elastomer (BPTE) produced through a simple and chemical‐free approach is introduced, utilizing alkali lignin, lipoic acid, and phytic acid as bio‐derived feedstocks. The BPTE exhibits an adaptive polymeric network crosslinked by dynamic covalent disulfide bonds and multiple hydrogen bonds, endowing it with dual‐mode photothermal conversion capability, robustness, stretchability, rapidly self‐healing property, hydrophobicity, swelling resistance, self‐adhesion, full recyclability, and degradability. The BPTE is further demonstrated as a next‐generation solution for photothermal generators, light‐driven actuators, photothermal antibacterial dressings, and photothermal fibers. The versatility of BPTE opens avenues for innovative smart devices and systems with significant potential in energy conversion, soft robotics, medical treatment, and smart clothing. With outstanding photothermal performances, full recyclability, and biodegradability, these fully bio‐based elastomers present an attractive prospect for the development of the advanced smart photothermal products.