Flexible films with wrinkled micro-nano hierarchical structures having stable superhydrophobicity under external loading

Flexible films possessing stable superhydrophobicity under external loading have great application potential in the emerging flexible electronics field. The effects of stretching and cyclic bending on superhydrophobicity and conductivity of the flexible films with wrinkled micro-nano hierarchical structures (W-FF) were investigated. Wrinkled micro-nano hierarchical structures were fabricated on a flexible film by pre-stretching, dipping and heating. Owing to that the interwoven network structures were always kept on the upper of the generated cracks and dendritic structures remained unchanged, the W-FF possessed stable superhydrophobicity and conductivity under stretching and cyclic bending. Effects of reaction time on the micro-nano hierarchical structures and superhydrophobicity were investigated. The formation mechanism of stable superhydrophobicity and conductivity of the W-FF under stretching and cyclic bending was studied by the characterization and comparison of the corresponding morphologies. The W-FF showed good motion sensing property when used as a real-time monitoring human motion sensor, such as monitoring facial muscle, wrist and finger movements. This superhydrophobic and conductive flexible film is expected to be applied in flexible electronics field.