Intrinsically stretchable electronics represent an attractive platform for next-generation implantable devices by reducing the mechanical mismatch and the immune responses with biological tissues. Despite extensive efforts, soft implantable electronic devices often exhibit an obvious trade-off between electronic performances and mechanical deformability because of limitations of commonly used compliant electronic materials. Here, we introduce a scalable approach to create intrinsically stretchable and implantable electronic devices featuring the deployment of liquid metal components for ultrahigh stretchability up to 400% tensile strain and excellent durability against repetitive deformations. The device architecture further shows long-term stability under physiological conditions, conformal attachments to internal organs, and low interfacial impedance. Successful electrophysiological mapping on rapidly beating hearts demonstrates the potential of intrinsically stretchable electronics for widespread applications in health monitoring, disease diagnosis, and medical therapies.

Stretchable and wearable sensors allow intimate integration with the human body for health and fitness monitoring. In addition to the acquisition of various physical parameters, quantitative analysis of chemical biomarkers present in sweat may provide vital insights into the physiological state of an individual. A widely investigated system utilizes electrochemical techniques for continuous monitoring of these biomarkers. The required supporting electronics and batteries are often challenging to form a deformable system. In this study, an intrinsically stretchable sensing patch is developed with compliant mechanical properties for conformal attachment to the skin and reliable collection of sweat. In these patches, superhydrophilic colorimetric assays consisting of thermoplastic polyurethane nanofiber textiles decorated with silica nanoparticles are assembled over a styrene− ethylene−butylene−styrene-based superhydrophobic substrate, thereby generating a large wettability contrast to efficiently concentrate the sweat. The system supports multiplexed colorimetric analysis of sweat to quantify pH and ion concentrations with images acquired using smartphones, in which the influence of ambient lighting conditions is largely compensated with a set of reference color markers. Successful demonstrations of in situ analysis of sweat after physical exercises effectively illustrate the practical suitability of the sensing patch, which is attractive for advanced health monitoring, clinical diagnostics, and competitive sports.

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.