On-skin devices that show both high performance and imperceptibility are desired for physiological information detection, individual protection, and bioenergy conversion with minimal sensory interference. Herein, versatile electrospun micropyramid arrays (EMPAs) combined with ultrathin, ultralight, gas-permeable structures are developed through a self-assembly technology based on wet heterostructured electrified jets to endow various on-skin devices with both superior performance and imperceptibility. The designable self-assembly allows structural and material optimization of EMPAs for on-skin devices applied in daytime radiative cooling, pressure sensing, and bioenergy harvesting. A temperature drop of ~4 °C is obtained via an EMPA-based radiative cooling fabric under a solar intensity of 1 kW m–2. Moreover, detection of an ultraweak fingertip pulse for health diagnosis during monitoring of natural finger manipulation over a wide frequency range is realized by an EMPA piezocapacitive-triboelectric hybrid sensor, which has high sensitivity (19 kPa−1), ultralow detection limit (0.05 Pa), and ultrafast response (≤0.8 ms). Additionally, EMPA nanogenerators with high triboelectric and piezoelectric outputs achieve reliable biomechanical energy harvesting. The flexible self-assembly of EMPAs exhibits immense potential in superb individual healthcare and excellent human-machine interaction in an interference-free and comfortable manner.

A heart-like micro-nanofiber based wearable HMN-TENG with mutually matched friction layers possesses great output performances.

No abstract

The utilization of nanoporous materials is an extremely effective approach to enhance the electrical performance of triboelectric nanogenerators (TENGs). However, existing methods for preparing nanoporous tribo-materials are not only complicated, costly and time-consuming, but also waste a lot of material. Meanwhile, fabricated nanoporous tribo-materials that have low roughness by nature possess poor surface hydrophobicity, causing low output stability in humid environments. Here, a bio-inspired petiole-like micron fiber-based tribo-material with inner nanopores, rough surface nanostructures and superhydrophobicity is first designed that uses an extraordinarily simple, ultralow-waste and efficient single-component electrospinning process. The petiole-like structures and superhydrophobicity endow the assembled triboelectric nanogenerator (PMF-TENG) with outstanding electrical performance and superior output stability under humid conditions. With a giant power density of 56.9 W m–2 and a high peak-to-peak output voltage of 2209 V, the optimized PMF-TENG can not only be used as a biomechanical energy harvester to directly drive 833 light-emitting-diodes and small electronics, but also serve as a self-powered sensor to detect body motions. Moreover, under a high relative humidity of 80%, the output retention rate of the optimized PMF-TENG is 1.7 and 2.2 times higher than the TENG assembled with the traditional smoother solid nanofiber-based tribo-material and the monolithic nanoporous tribo-material-based TENG, respectively. This work provides an easy-to-fabricate high-performance nanoporous material-based TENG with ultralow material waste and extends its potential for application in humid conditions.

No abstract

No abstract

Flexible electronic devices to obtain accurate and efficient information interactions between humans and machines have gained increasing attention in recent years. A series of soft materials for flexible electronics have been developed to improve device performance in terms of electrical and mechanical properties. Among them, conductive polymer-based hydrogels (CPHs), which combine the tunable electronic properties of conductive polymers and the soft mechanical properties of hydrogels, are promising candidates for nextgeneration wearable electronic devices. This review summarized the material design and preparation of CPHs, and presented the properties of CPHs, including tunable conductivity, outstanding mechanical performance, biocompatibility, self-healing capability, resistance to freezing, and solution processability.In particular, their emerging applications in flexible electronics devices including flexible supercapacitors, flexible sensors, and biomedical electronics are highlighted. Furthermore, perspectives on existing challenges and opportunities in this field are discussed.

Electronic skin is the flexible and wearable electronic system mimicking the functions and mechanical properties of the biological skin, which received increasing interest in recent years. Although efforts have been made to implement skin-like electronics in applications from everyday healthcare to advanced robotics, tremendous challenges in terms of immatual material selection and unbalanced device performances hinder its commercialization process. This Perspective covers the typical design difficulties of electronic skins, including effect of deformation on electrical properties, challenges in measuring precision and stability, integrating multisensories cooperatively, and manufacturing skills and process for large-scale production. In each section, works committed to solving such challenges from aspects of material modification, device preparation, and system design, together with potential research directions are highlighted.