Composite bilayer films with organic compound-triggered bending properties

Organic compounds are widely used in both industry and daily life, and composite bilayer films with organic compound-triggered bending properties are promising for applications of transducers, soft robotics, and so on. Here, a universal and straightforward strategy to generate composite bilayer films with organic compound-triggered bending properties is demonstrated. The composite bilayer films with organic compound-triggered bending properties are designed with bilayer structures, in which one layer is a porous polymeric membrane with appropriate solubility parameter that matches the value of organic solvents in order to produce prominent affinity to the solvent molecules, and the other layer is reduced graphene oxide membrane stacked on the porous polymeric membrane as an inert layer for restraining the swelling of the polymeric membrane on one side. Guided by matching the solubility parameters between solvent and polymer, a significant bending curvature of 27.3 cm−1 is obtained in acetone vapor. The results in this study will provide valuable guidance for designing and developing functional composite materials with significant organic compound-triggered bending properties.