Stretchable alternating current electroluminescent display is an emerging form of light-emitting device by combining elasticity with optoelectronic properties. The practical implementations are currently impeded by the high operating voltages required to achieve sufficient brightness. In this study, we report the development of dielectric nanocomposites by filling surface-modified ceramic nanoparticles into polar elastomers, which exhibit a series of desirable attributes, in terms of high permittivity, mechanical deformability, and solution processability. Dielectric nanocomposite effectively concentrates electric fields onto phosphor to enable low-voltage operation of stretchable electroluminescent display, thereby alleviating safety concerns toward wearable applications. The practical feasibility is demonstrated by an epidermal stopwatch that allows intimate integration with the human body. The high-permittivity nanocomposites reported here represent an attractive building block for stretchable electronic systems, which may find broad range of applications in intrinsically stretchable transistors, sensors, light-emitting devices, and energy-harvesting devices.

The rapid expansion of electronic technology and short lifespan of consumer devices create a huge amount of electronic waste. The disposal of discarded devices represents a serious environmental challenge. Biodegradable devices are able to decompose into benign components after a period of stable operation during its service life, which represents a potential solution to reduce the environmental footprint of electronic technology. The widespread applications of biodegradable electronics are still hampered by the lack of facile manufacturing approach for high quality devices. Here, a laser sintering technique to weld naturally oxidized Zn microparticles into biodegradable conductors is reported. The sintering process is carried out under ambient conditions and compatible with various biodegradable substrates. A low‐cost fabrication procedure involving stencil printing and laser treatment is established to create conductive features with excellent conductivity and mechanical durability. The practical suitability of printed Zn conductor is demonstrated by fabricating near‐field communication tags, which are flexible and fully functional with the transient behavior modulated by the choice of packaging materials. The printed biodegradable conductor may find potential applications in eco‐friendly sensors, transient printed circuit boards, and implantable medical devices.

Electronic textiles offer exciting opportunities for an emerging class of electronic technology featuring intimate interaction with the human body. Among various functional components, a stretchable conductive textile represents a key building material to support the development of sensors, interconnects, and electrical contacts. In this study, a conductive textile is synthesized by bottom-up coassembly of silver nanowires and TPU microfibers. The conformal coverage of AgNW network over individual TPU microfibers gives rise to coherent deformations to mitigate the actual strain for enhanced stretchability and durability. The as-prepared conductive microtextile exhibits a series of desirable properties including excellent conductivity (>5000 S cm–1), exceptional stretchability (∼600% strain), soft mechanical properties, breathability, and washability. The practical implementation is demonstrated by fabricating an integrated epidermal sensing sleeve for multichannel EMG signal recordings, which supports real-time hand gesture recognitions powered by machine learning algorithm as a smart human–machine interface. The conductive textile reported in this study is well suited for garment integrated electronics with potential applications in health monitoring, robotic prosthetics, and competitive sports.

Liquid metal confined in the elastomer represents an ideal platform for stretchable electronics with ultimate deformability. To enable facile and scalable patterning of conductive features, bulk liquid metal is typically dispersed into fine particles to formulate printable inks. The presence of native oxide or organic ligands stabilizing these liquid metal particles unfortunately inhibits their direct coalescence to recover the metallic conductivity and liquid-state deformability. Here, we report a chemical sintering process that converts printed liquid metal microparticles into a highly deformable conductor. The process involves the removal of surface passivating oxide by a short exposure to acid fume and subsequent selective wetting of liquid metal microparticles onto copper nanoplates present in the ink formulation. The chemical reaction provides the basis for a facile and scalable procedure to print conductive features over a large area with exceptional conductivity (>104 S cm–1) and ultrahigh stretchability (∼1000% strain). Their practical suitability is demonstrated by the fabrication of an ultrastretchable ribbon cable and an epidermal heater.