Superelastic, soft, stress-healable, recyclable conductive materials

Abstract

We report the design of materials with a unique combination of self-healing ability, electrical conductivity (8–150 Ohm·m), softness (G = 1 MPa), extremely low loss coefficient (tan δ ≈ 0.04) even at large deformations and linearity of resistivity dependence on strain in a broad range. The conductive material can bounce with very low energy dissipation at fast deformation, and it flows and self-heals at a large time scale and when sufficient stress is applied. The key to such properties is a combination of very stable interpenetrated networks formed by multiwalled carbon-nanotubes (MWCNT) filler and by viscoelastic polyborosiloxane (PBS) polymer matrix rendering relaxation processes and self-healing ability. We demonstrated the promise of the developed materials for the design of strain sensors with a very large linear regime and rubber-substitute as a protective coating or a sealing agent material.