Soft while strong mechanical shock tolerable e-skins

Abstract

Mechanical shock tolerance is of significance in developing high-performance e-skins. Herein, we report mechanical shock tolerable (MST) e-skins that spontaneously mimic the protection and sensing functions of natural skin. The MST e-skin was prepared using the conductive collagen fiber sponge (CFS) embedded with the elastic non-Newtonian gel (ENG). The MST e-skin is soft under relaxing conditions to provide a sensory capability, while it becomes stiff when engaged with mechanical shock to prevent mechanical failure. Upon engaged with mechanical shock, the conductive CFS plays the role as a fibrous load-bearing scaffold to dissipate mechanical energy, which also serves as pathways for efficient transmission of mechanical energy to reach the entire ENG surrounding the scaffold of CFS rather than the localized ENG in direct contact with the mechanical shock for energy dissipation via shear strengthening. The MST e-skins prolong the buffer time by 455% upon engaged with mechanical shock, with the peak force significantly reduced by 76.5%. Synergistically enhanced mechanical strength and consumption to mechanical shock energy exist between the conductive CFS and the ENG, which prevents the mechanical failure of MST e-skins after mechanical shock, allowing for retaining the sensory capability. Our investigations demonstrate a new conceptual strategy for developing mechanical shock tolerable e-skins.