Abstract Despite the remarkable progress in the development of sweat sensors, self‐powered sweat‐responsive sensing displays that detect sweat in electric signals with simultaneous and direct visualization of the sweat is rarely demonstrated. Here, a self‐powered sweat‐responsive structural color (SC) display enabled by ionomer‐doped block copolymer (BCP) photonic crystals (PCs) is presented. The sweat‐responsive BCP PC is developed by employing a cross‐linking single‐mobile ionomer (SMI) with mobile anions anchored to immobile polycations to a 1‐D BCP PC. The hydrophobic SMI‐doped BCP PC is mechanically robust as well as water and temperature‐resistive, exhibiting ionomer concentration‐dependent full visible SCs. Moreover, the mobile anions periodically confined in the SMI‐doped BCP PC harvest triboelectric energy, giving rise to a high‐power density of ≈0.774 Mw cm −2 . Cation‐sensitive SC variation is observed in the SMI‐doped BCP PC, allowing the visualization of sweat containing various cations. A skin‐patchable self‐powered sweat‐responsive display is demonstrated in which kirigami‐patterned SMI‐doped BCP PC incorporated in the display can withstand up to 50% strain during exercise. Sweat from the exercise is visualized via SC display and measured using both ionic resistance changes and triboelectric signals. In addition, the integration of sweat sensing membrane into SMI‐doped BCP PC enables the quantification of sweat.

The development of human-interactive sensing displays (HISDs) that simultaneously detect and visualize stimuli is important for numerous cutting-edge human-machine interface technologies. Therefore, innovative device platforms with optimized architectures of HISDs combined with novel high-performance sensing and display materials are demonstrated. This study comprehensively reviews the recent advances in HISDs, particularly the device architectures that enable scaling-down and simplifying the HISD, as well as material designs capable of directly visualizing input information received by various sensors. Various HISD platforms for integrating sensors and displays are described. HISDs consist of a sensor and display connected through a microprocessor, and attempts to assemble the two devices by eliminating the microprocessor are detailed. Single-device HISD technologies are highlighted in which input stimuli acquired by sensory components are directly visualized with various optical components, such as electroluminescence, mechanoluminescence and structural color. The review forecasts future HISD technologies that demand the development of materials with molecular-level synthetic precision that enables simultaneous sensing and visualization. Furthermore, emerging HISDs combined with artificial intelligence technologies and those enabling simultaneous detection and visualization of extrasensory information are discussed.

Structural colors (SCs) of photonic crystals (PCs) arise from selective constructive interference of incident light. Here, an ink-jet printable and rewritable block copolymer (BCP) SC display is demonstrated, which can be quickly written and erased over 50 times with resolution nearly equivalent to that obtained with a commercial office ink-jet printer. Moreover, the writing process employs an easily modified printer for position- and concentration-controlled deposition of a single, colorless, water-based ink containing a reversible crosslinking agent, ammonium persulfate. Deposition of the ink onto a self-assembled BCP PC film comprising a 1D stack of alternating layers enables differential swelling of the written BCP film and produces a full-colored SC display of characters and images. Furthermore, the information can be readily erased and the system can be reset by application of hydrogen bromide. Subsequently, new information can be rewritten, resulting in a chemically rewritable BCP SC display.

Abstract Despite the remarkable progress in the development of sweat sensors, self‐powered sweat‐responsive sensing displays that detect sweat in electric signals with simultaneous and direct visualization of the sweat is rarely demonstrated. Here, a self‐powered sweat‐responsive structural color (SC) display enabled by ionomer‐doped block copolymer (BCP) photonic crystals (PCs) is presented. The sweat‐responsive BCP PC is developed by employing a cross‐linking single‐mobile ionomer (SMI) with mobile anions anchored to immobile polycations to a 1‐D BCP PC. The hydrophobic SMI‐doped BCP PC is mechanically robust as well as water and temperature‐resistive, exhibiting ionomer concentration‐dependent full visible SCs. Moreover, the mobile anions periodically confined in the SMI‐doped BCP PC harvest triboelectric energy, giving rise to a high‐power density of ≈0.774 Mw cm −2 . Cation‐sensitive SC variation is observed in the SMI‐doped BCP PC, allowing the visualization of sweat containing various cations. A skin‐patchable self‐powered sweat‐responsive display is demonstrated in which kirigami‐patterned SMI‐doped BCP PC incorporated in the display can withstand up to 50% strain during exercise. Sweat from the exercise is visualized via SC display and measured using both ionic resistance changes and triboelectric signals. In addition, the integration of sweat sensing membrane into SMI‐doped BCP PC enables the quantification of sweat.

The development of human-interactive sensing displays (HISDs) that simultaneously detect and visualize stimuli is important for numerous cutting-edge human-machine interface technologies. Therefore, innovative device platforms with optimized architectures of HISDs combined with novel high-performance sensing and display materials are demonstrated. This study comprehensively reviews the recent advances in HISDs, particularly the device architectures that enable scaling-down and simplifying the HISD, as well as material designs capable of directly visualizing input information received by various sensors. Various HISD platforms for integrating sensors and displays are described. HISDs consist of a sensor and display connected through a microprocessor, and attempts to assemble the two devices by eliminating the microprocessor are detailed. Single-device HISD technologies are highlighted in which input stimuli acquired by sensory components are directly visualized with various optical components, such as electroluminescence, mechanoluminescence and structural color. The review forecasts future HISD technologies that demand the development of materials with molecular-level synthetic precision that enables simultaneous sensing and visualization. Furthermore, emerging HISDs combined with artificial intelligence technologies and those enabling simultaneous detection and visualization of extrasensory information are discussed.

Structural colors (SCs) of photonic crystals (PCs) arise from selective constructive interference of incident light. Here, an ink-jet printable and rewritable block copolymer (BCP) SC display is demonstrated, which can be quickly written and erased over 50 times with resolution nearly equivalent to that obtained with a commercial office ink-jet printer. Moreover, the writing process employs an easily modified printer for position- and concentration-controlled deposition of a single, colorless, water-based ink containing a reversible crosslinking agent, ammonium persulfate. Deposition of the ink onto a self-assembled BCP PC film comprising a 1D stack of alternating layers enables differential swelling of the written BCP film and produces a full-colored SC display of characters and images. Furthermore, the information can be readily erased and the system can be reset by application of hydrogen bromide. Subsequently, new information can be rewritten, resulting in a chemically rewritable BCP SC display.

An ink-jet printable and re-writable full color reflective mode display is developed by the position and concentration controlled deposition of a single, colorless, water base ink containing a reversible cross-linking agent, ammonium persulfate onto a transparent block copolymer photonic crystal film, as described in article number 1700084, by Edwin L. Thomas, Cheolmin Park and co-workers. The information is quickly written and erased over 50 times with resolution equivalent to that obtained with a commercial office ink jet printer.

This study quantitatively validated the applicability of the Global Product Classification for Korea(GPCK), developed for product safety management in online distribution markets, to government safety management policies. A database was constructed by separating and reorganizing raw accident data from the Consumer Injury Surveillance System of the Korea Consumer Agency into morpheme units. Using nominal-scale statistical analysis methods—Cramer's V coefficient and the chi-square test—the effect sizes and homogeneity among six categories of children’s products were analyzed. The results showed that the effect size between injury body parts and injury types was high(p<0.01), and that statistically significant differences were observed in the distribution of injury body parts among products classified within the same subcategory under the standard product classification system(p<0.05). These findings indicate that the GPC structure, which is primarily designed for the classification of distributed products, has limitations in adequately reflecting the detailed criteria required for domestic product safety policies aimed at safety management. Therefore, the study confirms that, in order to effectively apply the standard product classification system to the domestic product safety management framework, it is essential to introduce an attribute system at a level below the Brick level.

Despite the significant progress in the development of ionic junctions of two types of ionic conductors for ionic current rectification, reminiscent to electronic p- and n-type junctions, stimuli-responsive ionic junctions wherein stimuli reversibly control current rectification are seldom demonstrated. Here, we present a near-infrared (NIR)-responsive ionic junction and its application as a switchable logic gate. The NIR- responsive ionic junction is developed with a bilayer of ionoelastomers: liquid-free ionic conductors with mobile cations (p-type) and anion counterions (n-type) mixed with NIR-responsive 2D MXene (Ti₃C₂T_<i>x</i>) nanosheets sandwiched between two liquid metal electrodes. The study revealed that two types of MXene with positive and negative surface potentials incorporated into p- and n-type ionoelastomers, respectively, facilitated the diffusion of mobile ions. This resulted in an enhanced current rectification of an ionic diode. The rectification of an ionic junction is further increased upon NIR exposure to the device due to the photothermal energy conversion of MXene. A facile control of the rectification ratio with both exposure time and power of NIR enabled the development of a switchable ionic logic gate. Herein, the AND-to-OR gate transition was reversibly manipulated by NIR exposure and device cooling programmed to the two ionic junctions in series.

Correction for ‘Water-in-salt hydrogel electrolyte for dendrite-free Zn deposition’ by Varsha Joseph et al. , Energy Adv. , 2025, 4 , 1167–1178, https://doi.org/10.1039/D5YA00169B.