Light-driven reconfigurable electronics utilizing laser-induced graphene electrodes and azobenzene-functionalized liquid crystal elastomer substrates

초록

In recent years, smart materials, also known as stimuli-responsive materials, have driven advancements in deformable electronic devices, enabling active shape transformations beyond the passive deformations of traditional flexible electrodes. However, existing reconfigurable electrodes based on smart materials often rely on thermal stimuli, which limit their applications in environments where precise temperature control is challenging. Additionally, these systems are typically restricted to two-dimensional film configurations, confining their deformation modes to simple in-plane bending or twisting. To overcome these limitations, here we describe a novel reconfigurable electronic system, referred to as LIG-on-PI/A-cLCE (LPAL), by integrating bilayers of electrode and substrate. The electrode layer is prepared by formation of laser-induced graphene (LIG) on a commercial polyimide film and the substrate layer is prepared by azobenzene-functionalized semi-crystalline liquid crystal elastomer (A-cLCE). LIG provides electrical conductivity to the system, while A-cLCE enables on-demand shape reconfiguration through photoisomerization under UV or visible light stimuli. LPAL eliminates reliance on thermal stimuli, allowing non-contact actuation including underwater environments, while maintaining stable electrical conductivity during repeated deformations. Furthermore, leveraging the crystallinity-assisted restructuring of A-cLCE, we fabricated a three-dimensional spiral-LPAL, achieving exceptional stretchability (similar to 200 % strain) and retaining 100 % original conductivity after 1000 cycles of tensile deformation. This spiral design introduces reversible lengthwise contraction and elongation under light stimuli, expanding deformation capabilities beyond conventional in-plane modes. Finally, we demonstrate the versatility of spiral-LPAL by implementing an untethered electrical switch functions in both ambient and underwater environments, showcasing its potential for advanced reconfigurable systems.

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