In the past several years, wearable pressure sensors have engendered a new surge of interest worldwide because of their important applications in the areas of health monitoring, electronic skin, and smart robots. However, it has been a great challenge to simultaneously achieve a wide pressure-sensing range and high sensitivity for the sensors until now. Herein, we proposed an innovative strategy to construct multilayer-structure piezoresistive pressure sensors with an in situ generated thiolated graphene@polyester (GSH@PET) fabric via the one-pot method. Taking advantage of the spacing among the rough fabric layers and the highly conductive GSH, the sensor realized not only a wide pressure range (0–200 kPa), but also high sensitivity (8.36 and 0.028 kPa–1 in the ranges of 0–8 and 30–200 kPa, respectively). After 500 loading–unloading cycles, the sensor still kept high sensitivity and a stable response, exhibiting great potential in long-term practical applications. Importantly, the piezoresistive pressure sensor was successfully applied to accurately detect different human behaviors including pulse, body motion, and voice recognition. Additionally, the sensing network integrated by the sensors also realized mapping and identifying spatial pressure distribution. Our method to construct the wide-range and high-sensitivity piezoresistive pressure sensor is facile, cost-effective, and available for mass production. The findings provide a new direction to fabricate the new-generation high-performance sensors for healthcare, interactive wearable devices, electronic skin, and smart robots.

A lot of attention has recently been focused on wearable strain sensors because of their promising applications in the rising areas of human motion detection, health monitoring, and smart human−machine interaction. However, the design and fabrication of self-healable strain sensors with superior overall properties including stretchability, sensitivity, response ability, stability, and durability is still a huge challenge. Herein, we report an innovative self-healable strain sensor with exceptional overall performance constructed with three-dimensional binary-conductive-network silver nanowire-coated thiolated graphene foam (AgNWs@TGF) and room-temperature self-healing functionalized polyurethane (FPU) elastomer. Taking advantage of the good ductility and continuity of the AgNWs@TGF binary structure and the excellent resilience of the FPU, the strain sensor exhibits good stretchability (up to 60% strain), high sensitivity [gauge factor (GF) of 11.8 at 60% strain and detection limit of 0.1% strain], fast response ability (response/recovery time of 40/84 ms), and exceptional durability for 800 cycles of fatigue test. Besides, the highly flexible polydimethylsiloxane chains, strong intermolecular hydrogen bonding, and dynamic exchange reaction of aromatic disulfides ensure the sensor excellent recovery property of electrical conductivity, and the GF of sensor after self-healed only increases slightly. More importantly, the sensor is successfully applied for detecting a variety of human motions including pulse beats, voice recognitions, various joint movements, and handwriting. The method for preparing room-temperature self-healable strain sensor is facile, scalable, and cost-effective. The finds provide a new perspective on fabricating new-generation high-performance and functional strain sensors for health monitoring, wearable electronics, and intelligent robots.

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Conductive smart hydrogels with several virtues such as similar characters to biological tissues, sensitive response to ambient variations, have shown their excellent talents in the field of flexible electrical sensors, biomedical devices and directional transportation. However, complex preparing approaches or the instable inner structures have not only been time‐consuming, but also broken up the performance and reliability of the smart hydrogel‐based devices. In this work, a facile one‐step method is put forward to synthesize a kind of conductive poly(N‐isopropylacrylamide) (PNIPAM) hydrogel doped by a new green solvent of deep eutectic solvent (DES) containing choline chloride (ChCl) and acrylic acid (AA). Through the copolymerization of AA and NIPAM, the mechanical strength of the DES‐doped PNIPAM hydrogels is drastically improved compared to the pure PNIPAM gels, and some doped hydrogels lost the typical phase transition temperature of PNIPAM. Moreover, due to the ionic property of DES, the hybrid hydrogels also present the thermal‐depending conductivity as well as sensitive deformation response, which can be used as a smart switch in a circuit or a sensing element with environmental response ability. The cost‐effective preparation and the attractive performance of the DES‐doped hydrogels offer a new avenue to construct multi‐functional materials.

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