Soft and Strong: Elastic Conductors with Bio‐Inspired Self‐Protection

Abstract

Abstract Skin is soft yet strong – a combination achieved by integrating compliant elastin with stiff but wavy collagen, producing non‐linear mechanical properties. Inspired by this structure, stiff conductive wires are engineered into sinusoidal patterns and mechanically interlocked them with highly elastic fibers using a reimagined woven fabric approach. The result is a highly conducting and stretchable yarn that also has high tensile strength – a combination that is attractive for wearable applications where comfort and durability are valued. With a diameter of ≈1 mm—comparable to many commercial yarns—the fabric‐based yarn exhibits low stiffness across a broad strain range (up to 270% under 2 N of force) while demonstrating a self‐protective transition to high stiffness and strength (up to 30 MPa) as it nears failure. Additionally, this yarn offers excellent flexibility, high strain tolerance (exceeding 500%), inherent breathability, and superior weavability. By tuning the number of elastic fibers and electrode fibers, it can further tailor these stretchable conductive yarns into strain‐insensitive connecting yarns (low impedance at MHz frequencies, GF = 0.0003) and mechanical sensing yarns with dual strain and proximity sensing capabilities. The integration of these functional yarns enables system‐level smart textile applications, such as wristband controllers.