A Facile and Rapid Approach to Lotus‐Seedpod‐Structured Electronic Skin for Monitoring Diverse Physical Stimuli

Abstract

AbstractAlthough the burgeoning Internet of Things has created soaring demand for electronic skin (e‐skin), a facile and eco‐friendly approach towards the scalable fabrication of the hierarchical active layer for such a system is still limited in the stage of development. Herein a sensing layer with lotus‐seedpod‐like structures is reported that is readily prepared by multi‐melt multi‐injection molding (M3IM). Because of the shear flow and thermodynamic factors in M3IM, silica microspheres in the core layer of the polyethylene/silica composite are inclined to migrate to the interface between the skin layer of ethylene‐α‐octene block copolymer/carbon nanotube composite and core layer, resulting in lotus‐seedpod‐like structures consisting of micro‐pits and asperities formed on the surface of the peeled skin layer. The sensitivity of the fabricated e‐skin is significantly affected by the number of micro‐pits on the lotus‐seedpod‐like structure, which mainly depend on the silica mass fraction in the composites. For instance, the e‐skin made from the composites with 66.67 wt% silica exhibits a sensitivity of 19.87 kPa−1 over a wide linear range of 0.017–11.5 kPa and demonstrates excellent durability and reproducibility, enabling multiple signal detection. This work sheds light on the rapid and scalable fabrication of sensors using a polymer melt processing strategy.