One-pot molten strategy to synthesize tough bio-derived lignin-based photothermal elastomers for photoelectric driven and programmable shape memory

Utilizing renewable biomass as an alternative to petroleum-based products for the development of smart materials emerges as a pivotal strategy for sustainable development. However, the straightforward, rapid, and cost-effective deployment of biomass for novel smart material synthesis remains a formidable challenge. Herein, we employ a facile solvent-free one-pot strategy to develop a multifunctional smart biomass photothermal elastomer, which synthesized from the natural small molecule of α-lipoic acid (LA) and renewable lignin biopolymer without any chemical modification. The incorporation of lignin confers to the obtained elastomers superior mechanical strength, photothermal responsiveness, photothermal self-healing, and adhesive capabilities. Notably, the photothermal elastomers can be fully recycled and reused by simple thermal remodeling. As a proof of concept, the temperature difference generator can be driven to generate electricity utilizing the excellent photothermal effect of elastomers, highlighting its excellent light-heat-electricity conversion capability. Intriguingly, the photothermal elastomers exhibit light-driven shape memory effect, enabling to grasp objects by shape-programmed four-arm soft gripper under selective irradiation. This pioneering work not only demonstrates significant progress in high-value utilization of bio-derived lignin, but also opens up a new avenue for sustainable and innovative applications in advanced energy management devices and soft actuators.