Stretchable materials of high toughness and low hysteresis

Abstract

Significance Many applications in engineering require stretchable materials that dissipate little energy during normal operation of cyclic loads (low hysteresis), but dissipate much energy to resist rupture (high toughness), and survive prolonged cyclic loads (fatigue resistant). However, existing stretchable materials cannot meet these requirements simultaneously. Here we present a principle to achieve this goal, and demonstrate the principle by a composite of two stretchable materials of low hysteresis, with large modulus contrast and strong adhesion. The composite retains the low hysteresis, but is much tougher and more fatigue resistant than the constituents. The same principle applies to elastomers, gels, and elastomer–gel hybrids. This class of materials provides opportunities to create high-cycle and low-dissipation soft robots and soft human–machine interfaces.