Highly stretchable liquid metal/polyurethane sponge conductors with excellent electrical conductivity stability and good mechanical properties.

An all-soft, highly stretchable liquid metal (LM) conductor with high electrical conductivity, excellent electrical conductivity stability under various mechanical deformations and good mechanical properties was achieved. The stretchable conductor was prepared by infiltrating Gallium-indium-tin (GIT) LM into porous polyurethane sponge (PUS) with large porosity and small pores using a vacuumizing method followed by encapsulation with Polydimethylsiloxane (PDMS) to prevent the leakage of GIT-LM and to improve the mechanical properties. The as-made PDMS/PUS/LM composite shows a high tensile strength (1.11 MPa), high elongation at break (419%), excellent electrical conductivity (104 S/cm) and electrical conductivity stability under various mechanical deformations. The normalized resistance is of highly repeatability in stretch-release and bend-release cycle experiments. Image 1 • A highly stretchable liquid metal/polyurethane sponge conductor was prepared. • A dense LM network was formed due to the large porosity and small pores of PUS. • The conductor shows high conductivity stability under mechanical deformations. • A good interfacial interaction between PUS and LM was achieved. • The conductor shows relatively high tensile strength and high elongation at break. [ABSTRACT FROM AUTHOR]