A biomimetic conductive super-foldable material

The further development of flexible electronics inevitably requires conductive materials to have numerous foldable properties; however, that has not been realized. Here, inspired by silkworm cocooning processes, we prepare a super-foldable conductive carbon material with layered nanofiber network structures through an improved electrospinning/carbonization technique. It can remarkably bear 1,000,000 times repeated true-folding without structural damage and conductivity fluctuations. The root of such performance break. through is revealed through real-time SEM folding observation and mechanical simulations. Its structures featuring appropriate pores, non-crosslinked junctions, slidable nanofibers, separable layers, and a compressible network can act synergistically to generate a epsilon-like folding construction at crease under true-folding, which can completely disperse stress via bulged layers, dispersed arcs, and slidable grooves in epsilon. Consequently, each nanofiber avoids directly facing with 180 degrees folding when the whole material is true-folded. This work embodies structure innovation, performance breakthrough, and mechanism reveal, which has great scientific significance and application prospects.

Automated summary

This study presents a super-foldable conductive carbon material with layered nanofiber network structures, capable of withstanding 1,000,000 times repeated true-folding without damage and conductivity fluctuations. The unique structure of the material can disperse stress and prevent nanofibers from directly facing 180 degrees folding during true-folding.