The ability to image pressure distribution over complex three-dimensional surfaces would significantly augment the potential applications of electronic skin. However, existing methods show poor spatial and temporal fidelity due to their limited pixel density, low sensitivity, or low conformability. Here, we report an ultraflexible and transparent electroluminescent skin that autonomously displays super-resolution images of pressure distribution in real time. The device comprises a transparent pressure-sensing film with a solution-processable cellulose/ nanowire nanohybrid network featuring ultrahigh sensor sensitivity (>5000 kPa −1 ) and a fast response time (<1 ms), and a quantum dot-based electroluminescent film. The two ultrathin films conform to each contact object and transduce spatial pressure into conductivity distribution in a continuous domain, resulting in super-resolution (>1000 dpi) pressure imaging without the need for pixel structures. Our approach provides a new framework for visualizing accurate stimulus distribution with potential applications in skin prosthesis, robotics, and advanced human-machine interfaces.

By the combination of the inkjet printing of PEDOT:PSS transfer template and selective transfer of silver nanowires (AgNW), AgNWs of customizable transparency can be patterned with high degree of freedom, without need of high equipment cost and complicated process. The AgNW‐transferred PEDOT:PSS transparent electrodes exhibit both great figure of merit and easily tunable optoelectronic properties. With maintaining the advantages and overcoming the issues of the AgNWs, the method developed by Yongtaek Hong and co‐workers in article number 2000042 can be applied to various flexible electronics.

Inkjet and transfer printing processes are combined to easily form patterned poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as top anodes of all solution-processed inverted polymer light emitting diodes (PLEDs) on rigid glass and flexible plastic substrates. An adhesive PEDOT:PSS ink is formulated and fully customizable patterns are obtained using the inkjet printing process. In order to transfer the patterned PEDOT:PSS films, adhesion properties at interfaces during multistep transfer printing processes are carefully adjusted. The transferred PEDOT:PSS film on the plastic substrates shows not only a sheet resistance of 260.6 Ω/□ and a transmittance of 92.1% at 550 nm wavelength but also excellent mechanical flexibility. The PLEDs with spin-coated functional layers sandwiched between the transferred PEDOT:PSS top anodes and inkjet-printed Ag bottom cathodes are fabricated. The fabricated PLEDs on the plastic substrates show a high current efficiency of 10.4 cd A −1 and high mechanical stability. It is noted that because both Ag and PEDOT:PSS electrodes can be patterned with a high degree of freedom via the inkjet printing process, highly customizable PLEDs with various pattern sizes and shapes are demonstrated on the glass and plastic substrates. Finally, with all solution process, a 5 × 7 passive matrix PLED array is demonstrated.

Stretchable organic light‐emitting diodes (OLEDs) have been considered as a promising technology for next‐generation free‐form and wearable displays. However, an approach to ensure both high device performance and high resolution has not yet been suggested. While introducing a wrinkled structure in the active pixel areas is a decent method, the formation of out‐of‐plane macroscopic wrinkles having a wavelength of a few hundred µm has caused distortion in the shape of the pixel, which is a critical drawback for a matrix‐configured display demanding a sharp pixel definition. Herein, microwrinkled OLEDs are fabricated to define a distortion‐free pixel by direct deposition of OLEDs on biaxially prestretched elastomeric substrate, being feasible by a low‐temperature‐based solution process. The total thickness of the device can be significantly reduced up to 350 nm, producing the imperceptible microwrinkles having a wavelength under 20 µm. The microwrinkled OLEDs show a luminance over 8000 cd m−2 and maximum current efficiency of 7.76 cd A−1, which is comparable to the device without wrinkled structure. Finally, a stretchable 4 × 4 OLED pixel array with a microwrinkled structure is demonstrated showing sharply defined square‐patterned emission, proving the potential in the future high‐resolution stretchable display.

Seamless tiling of displays is one of the key enabling technologies for the next-generation large-area electronics applications. In this paper, we propose a facile method to demonstrate a seamless display using cylindrical lens pair (CLP) fabricated by dispenser printing method. Optical properties of the printed CLP and corresponding capability of concealing seam in the display are analyzed by a set of luminance simulation and measurement in terms of geometric parameters of the lens. The seamless display with an optimized CLP features a viewing angle of the seam concealment of 40°.

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A stretchable display would be the ultimate form factor for the next generation of displays beyond the curved and foldable configurations that have enabled the commercialization of deformable electronic applications. However, because conventional active devices are very brittle and vulnerable to mechanical deformation, appropriate strategies must be developed from the material and structural points of view to achieve the desired mechanical stretchability without compromising electrical properties. In this regard, remarkable findings and achievements in stretchable active materials, geometrical designs, and integration enabling technologies for various types of stretchable electronic elements have been actively reported. This review covers the recent developments in advanced materials and feasible strategies for the realization of stretchable electronic devices for stretchable displays. In particular, representative strain‐engineering technologies for stretchable substrates, electrodes, and active devices are introduced. Various state‐of‐the‐art stretchable active devices such as thin‐film transistors and electroluminescent devices that consist of stretchable matrix displays are also presented. Finally, the future perspectives and challenges for stretchable active displays are discussed.

Facile high-resolution patterning of silver nanowires (AgNWs) is a key enabling technology for expanding their usage to flexible and stretchable electronics applications. Although various patterning methods have been proposed, only high-cost and complex mask-based methods demonstrated potential micrometer-scale pattern-ability with no design freedom of changing patterns in a facile manner. Herein, we suggest a maskless high-resolution patterning method by combining an adhesive under-layer and inkjet-printed conductive polymer patterns. AgNWs located between them are tightly bonded and thus, are resistive to a solvent-based rinsing process. AgNWs under the conductive polymer patterns remain while uncovered AgNWs are removed during the rinsing process. Our approach allows easy patterning of AgNWs on various substrates including glass, plastic, and stretchable elastomer. An excellent mechanical property of AgNWs interconnects are demonstrated in a stretchable light-emitting diode array. By introducing an electrohydrodynamic printing method, high-resolution AgNW patterns with linewidths below 20 µm are fabricated, which are used for a heater based on transparent grid AgNWs electrodes. Based on our results, we believe that our method paves the way for a convenient patterning process of high-resolution electrode circuits with a high degree of freedom even on a deformable platform.