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.

Polymeric materials are emerging as an important component for organic electronics due to their combined features of soft materials and organic semiconductor/conductor. Different from solid-state bulk materials, polymers are synthesized and modulated with a facile method, with their controllable properties. Therefore, polymers have been recently used in Schottky junction devices that demonstrate features of enhanced performances, flexibility, and easy processing. Polymer-based Schottky junctions have drawn a lot of interest in several prototype applications like photodetectors, energy harvesters, and gas sensors. With this review, we summarize recent progress in synthesis and modulation of polymers and fabrication of polymer-based Schottky junction devices. Designs of applications of sensory devices like photodetectors, energy harvesters, and gas sensors are also presented.

Flexible pressure sensors that emulate the sensation and characteristics of natural skins are of great importance in wearable medical devices, intelligent robots, and human–machine interfaces. The microstructure of the pressure-sensitive layer plays a significant role in the sensor’s overall performance. However, microstructures usually require complex and costly processes such as photolithography or chemical etching for fabrication. This paper proposes a novel approach that combines self-assembled technology to prepare a high-performance flexible capacitive pressure sensor with a microsphere-array gold electrode and a nanofiber nonwoven dielectric material. When subjected to pressure, the microsphere structures of the gold electrode deform via compressing the medium layer, leading to a significant increase in the relative area between the electrodes and a corresponding change in the thickness of the medium layer, as simulated in COMSOL simulations and experiments, which presents high sensitivity (1.807 kPa⁻¹). The developed sensor demonstrates excellent performance in detecting signals such as slight object deformations and human finger bending.

Pressure sensors are widely used in intelligent systems. With the extension of application conditions, pressure sensors with energy-sustainable, large-area, and high-density are urgently needed to be designed. In this article, we proposed a polymer/metal Schottky junction structure to achieve flexible self-powered pressure sensors (SPSs), in which the Schottky junction has the capability of converting mechanical energy to direct current (DC) without external rectifier. The constructed pressure sensor holds a sandwich structure simply made up of an Au layer, a p-type semiconductor polypyrrole layer, and an Al layer. Test results show that this pressure sensor has the ability of self-power supply with output 0.79 V DC voltage which is almost independent of the area of pressure sensor, and has an outstanding output power density of 33.4 μ W cm ⁻² , a high response speed with 33 ms, and a good sensitivity of 0.0143 V kPa ⁻¹ in the pressure range of 0–60 kPa. Furthermore, it can sense both the dynamic and static forces. This work provides a simple but efficient method to develop SPSs, which show potentials in electronic skin with tactile function and artificial intelligence.