Shrinkage-transfer-assisted printing of microcircuits on fibers.

Fiber represents a transformative architecture for next-generation wearable electronics, owing to its intrinsic flexibility, spatial compactness, and manufacturing adaptability. However, the geometric incompatibility between curved fiber substrates and conventional planar photolithography/printing techniques has hindered the fabrication of high-density microcircuits on fibers. Here, we introduce a shrinkage-transfer-assisted printing (STAP) strategy that bridges 2D planar circuit fabrication and 1D fiber device construction by shrinking fluidic eutectic gallium-indium (EGaIn) circuits and transferring them onto curved fiber surfaces. This approach achieves a shrinkage ratio of up to 80% with a resolution of 60 μm via scalable screen printing, and employs a capillary-driven transfer process to realize 360° conformal coverage of circuits on fibers. The resulting fiber devices exhibit mechanical robustness over 16,000 bending cycles. As a proof of concept, we demonstrate an electroluminescent fiber display system with individually addressable pixels. This work provides a versatile strategy for manufacturing microcircuits on curved fiber surfaces, opening a route toward scalable and multifunctional fiber electronics.