Stretchable electroluminescent device is a compliant form of light-emitting device to expand the application areas of conventional optoelectronics on rigid wafers. Currently, practical implementations are impeded by the high operating voltage required to achieve sufficient brightness. In this study, we report the fabrication of an intrinsically stretchable electroluminescent device based on silver nanowire electrodes and high-k thermoplastic elastomers. The device exhibits a bright emission with a low driving voltage by using polar elastomer as a dielectric matrix of the electroluminescent layer. Highly stretchable silver nanowire electrodes contribute to the exceptional elasticity and durability of the device in spite of bending, stretching, twisting, puncturing, and cutting. Stretchable electroluminescent devices developed here may find potential uses in wearable displays, deformable lightings, and soft robotics.

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.

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.

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To investigate the evolution of inclusions in high‐Al steel with addition of La, a series of laboratory experiments and thermodynamic calculations are performed, considering the reaction time and amount of La added. The main inclusions in the high‐Al steel without the addition of La are Al2O3, MnS, and Al2O3–MnS. The La treatment can efficiently modify Al2O3 to La–Al–O or La–O–S inclusions. For La additions less than 0.0041 wt%, the evolution route for the inclusion in high‐Al steel is Al2O3 → LaAl11O18 → LaAlO3 with an increase in reaction time. For high La additions, the evolution route for the Al2O3 inclusion is Al2O3 → LaAl11O18 → LaAlO3 → La2O2S → La2S3. The experimental results correlate with those of the thermodynamic analysis. Notably, excess La in high‐Al molten steel may consume O and S to form La oxysulfide and sulfide, respectively, which prevents the precipitation of MnS inclusion and promotes the formation of AlN inclusion during solidification.

Liquid metal represents a highly conductive and inherently deformable conductor for the development of stretchable electronics. The widespread implementations of liquid metal towards functional sensors and circuits are currently hindered by the lack of a facile and scalable patterning approach. In this study, we report a fully solution-based process to generate patterned features of the liquid metal conductor. The entire process is carried out under ambient conditions and is generally compatible with various elastomeric substrates. The as-prepared liquid metal feature exhibits high resolution (100 μm), excellent electrical conductivity (4.15 × 104S cm−1), ultrahigh stretchability (1000% tensile strain), and mechanical durability. The practical suitability is demonstrated by the heterogeneous integration of light-emitting diode (LED) chips with liquid metal interconnects for a stretchable and wearable LED array. The solution-based technique reported here is the enabler for the facile patterning of liquid metal features at low cost, which may find a broad range of applications in emerging fields of epidermal sensors, wearable heaters, advanced prosthetics, and soft robotics.

Biodegradable electronic devices are able to break down into benign residues after their service life, which may effectively alleviate the environmental impacts as a consequence of the proliferation of consumer electronic technology. The widespread adaptation to biodegradable systems is currently impeded by the lack of economic fabrication techniques for functional devices. Here, a facile approach to generate a biodegradable conductor is developed based on selective laser sintering of zinc and iron microparticle ink. The sintering process is effective to convert naturally oxidized microparticles into interconnected conductors. Arbitrary conductive features are readily created over flexible biodegradable substrates under ambient conditions, which exhibits excellent conductivity (∼2 × 106 S m–1), low sheet resistance (∼0.64 Ω □ – 1), fine feature resolution (∼45 μm), and mechanical flexibility. The practical suitability is demonstrated by fabricating a miniaturized near-field communication tag with the dimension to mount on the fingernail. The methodology is further extended to create a metallic grid as a biodegradable transparent electrode with low sheet resistance (2.5 Ω □–1) and high optical transmittance (96%), which is employed as an epidermal transparent heater for thermotherapy. Maskless patterning of biodegradable conductors may find a broad range of applications in environment friendly gadgets and implantable medical devices.

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