Fully printed wearable electronics for superhuman sensing in augmented reality

Wearable electronics increasingly demand circuit architectures that combine intrinsic softness with high-level functionality, yet most printed soft systems remain constrained to single-layer, low-complexity layouts. Here we introduce two complementary, fully printed platforms that address this gap: an intrinsically soft, liquid metal–based composite ink for rapid multilayer overpass routing, and a flexible silver nanoparticle (AgNP) system on thermally stable acrylic-coated biaxially-oriented polyethylene terephthalate (AC-BOPET) for solderable, mechanically robust patches. The first approach employs a styrenic block copolymer matrix loaded with eutectic gallium–indium droplets, silver microflakes, and a percolating carbon nanotube network, yielding a shear-thinning ink that supports high-fidelity multilayer direct ink writing, vapor-induced repair, and digital circuits incorporating microcontrollers, memory, wireless modules, and CMOS imaging. The second approach establishes a direct ink write process using low temperature solder and thermally treated flexible substrates to yield scalable, robust, and rapid circuit manufacturing. Together, these results outline a materials and process framework for rapidly fabricating conformal, multilayer wearable patches that span from highly customizable, intrinsically soft systems to scalable and highly manufacturable soldered flexible electronics.