Tendon‐Inspired Defect‐Tolerant Hybrid Elastomers for Customizable, Ultra‐Sensitive Strain Sensing

ABSTRACT Flexible strain sensors have attracted widespread attention in fields such as industrial inspection and medical monitoring. However, the low intrinsic fracture toughness of elastomers widely used in flexible electronics cannot accommodate customized designs for strain transduction structures, thus limiting the synchronous enhancement of transduction stability and strain sensitivity. Here, inspired by the high toughness and tear resistance of biological tendons, a bionic hybrid elastomer design concept with defect tolerance properties is proposed. The hybrid elastomer reveals a fracture toughness as ∼11.5 kJ/m 2 and a tear toughness as 115.7 kJ/m 2 , ensuring sensing stability in designed transduction structures. Capitalizing on this, we engineered separate strain transduction structures targeting tensile strain and bending compressive strain monitoring. Strain‐mediated contact‐separation kinetics enable remarkable sensitivity in small strain and impressive electrical performance (including the capability to detect subtle frequency/strain variations and high overload resistance). Finally, applications for monitoring various small and local strains are explored, which results indicate that customized strain sensors can provide a sensing platform for fields such as structural deformation assessment and human gait analysis.