Pressure-stamped stretchable electronics using a nanofibre membrane containing semi-embedded liquid metal particles

Abstract

Stretchable electronic devices are of use in the development of bioelectronics, wearable devices and healthcare monitoring. Liquid-metal-based stretchable devices are of particular interest for such systems but typically require complex manufacturing processes and suffer from poor interfacial adhesion between the liquid metal and polymeric substrates. Here we show that a membrane of electrospun polymer fibres containing semi-embedded liquid metal particles can be used to make stretchable electronics. The liquid metal particles within the fibre network rupture under pressure and fill the gaps in the fibre mesh to form conductive regions. This enables the creation of circuits with high resolution (minimum linewidths of 50 µm) and stability (over 30,000 cycles of 100% strain) using circuit-patterned stamps. The circuits can be integrated with various electronic components to achieve different functions, including square wave signal output, light emission and wireless charging. We used this approach to create sensors for bioelectrical signal monitoring, thus illustrating the biocompatibility and permeability of the membranes. We also show that the liquid-metal-containing fibre membranes can be separated into their individual components and recycled. A membrane of polymer fibres containing semi-embedded liquid metal particles can be selectively ruptured with a patterned stamp to produce stretchable circuits with high resolution and interfacial adhesion between the liquid metal and the polymer.