The skin is the largest organ of the human body and can sense pressure, temperature, and other complex environmental stimuli or conditions. The mimicry of human skin's sensory ability via electronics is a topic of innovative research that could find broad applications in robotics, artificial intelligence, and human–machine interfaces, all of which promote the development of electronic skin (e‐skin). To imitate tactile sensing via e‐skins, flexible and stretchable pressure sensor arrays are constructed based on different transduction mechanisms and structural designs. These arrays can map pressure with high resolution and rapid response beyond that of human perception. Multi‐modal force sensing, temperature, and humidity detection, as well as self‐healing abilities are also exploited for multi‐functional e‐skins. Other recent progress in this field includes the integration with high‐density flexible circuits for signal processing, the combination with wireless technology for convenient sensing and energy/data transfer, and the development of self‐powered e‐skins. Future opportunities lie in the fabrication of highly intelligent e‐skins that can sense and respond to variations in the external environment. The rapidly increasing innovations in this area will be important to the scientific community and to the future of human life.

A triboelectric sensor matrix (TESM) can accurately track and map 2D tactile sensing. A self-powered, high-resolution, pressure-sensitive, flexible and durable TESM with 16 × 16 pixels is fabricated for the fast detection of single-point and multi-point touching. Using cross-locating technology, a cross-type TESM with 32 × 20 pixels is developed for more rapid tactile mapping, which significantly reduces the addressing lines from m × n to m + n.

In this study, we report an Er-doped quaternary piezoelectric semiconductor CaZnOS:Er3+ which shows both mechanoluminescence and upconversion luminescence properties. Under mechanical stimulation, green light emission can be observed by the naked eye from a flexible film fabricated by encapsulating CaZnOS:Er3+ particles between two polyethylene glycol terephthalate substrates. The integral emission intensity is proportional to applied pressure, making CaZnOS:Er3+ suitable for dynamic pressure sensing applications. Moreover, the doped sample also shows bright visible emission with near-infrared (980 nm) excitation. The fluorescence intensity ratio between two upconversion emission bands corresponding to 2H11/2, 4S3/2 → 4I15/2 transitions of Er3+ is sensitive to the variation of temperature. As a multifunctional optical material, CaZnOS:Er3+ could be used to not only visualize two-dimensional pressure distribution, through mechanically induced emission, but also sense temperature via the upconversion (UC) luminescence. This work provides a novel kind of multifunctional luminescent material for the development of integrated and coupling devices.

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