Flexible pressure sensors play a vital role in advancing the Internet of Things (IoT). However, piezoelectric sensors are limited in static pressure detection and suffer in achieving high flexibility and high sensitivity simultaneously, while piezoresistive sensors typically have slow response speeds and insensitive high-frequency detection ability. Here, we select a novel basalt fiber fabric (BFF) that can withstand high temperatures exceeding 1000 °C as a new substrate to enable one-step fabrication of piezoelectric layer based on coherently grown Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin films via a simple dipping method. The high piezoelectric coefficient g 33 of 362.5 mV·m·N −1 and the unique core-sheath structure induced stress concentration on the PZT sheath enable the flexible piezoelectric layer (bending radius < 1.45 mm) to exhibit high sensitivity (voltage sensitivity of 2.766 V/kPa within the range of 0.11–11.11 kPa) and fast response speed (11 ms). The piezoresistive layer consisting of a three-dimensional porous elastic carbon nanotube-polyurethane sponge provides a detection range comparable to piezoelectric layer (0.11–66.67 kPa). A dual-mode flexible pressure sensor (DMFS) has been developed by integrating the piezoelectric layer with the piezoresistive layer. The DMFS exhibits an extended detection range compared to previous dual-mode pressure sensors, rapid response speed, and high sensitivity, which enables simultaneous detection of both dynamic and static pressures. The DMFS can be used for keyboard and movement posture recognition, which has significant application prospects in human-machine interaction.
Guangzhi Yang,Chenkai Cao,Haoran Zhong,Yu Cheng,Wenhui Zhang,Ding Wang
As a typical pollution gas , xylene poses a particularly serious threat to human health. The xylene sensors with low operating temperature, fast response speed, sufficient detection limit and satisfactory selectivity are required for safety protection. Herein, a novel xylene sensitive material (SnO 2 @MoS 2 ) was constructed by self-assembling MoS 2 nanosheets array on SnO 2 nanofibers . The response of SnO 2 @MoS 2 sensor was 23.5–100 ppm xylene vapor, which was much higher than that of single-component sensors. Additionally, the response/recovery times were 21.5/60.4 s with a limit of detection (LOD) as low as 0.5 ppm. The good sensitive was ascribed to the unique resistance characteristics of the hierarchical structure, the regulation of electronic property by heterojunctions , and the increase of adsorption sites caused by large specific surface areas and surface defects . This work enlightens a novel strategy on the construction of MoS 2 based core-shell hierarchical nanomaterials and future development of high efficiency xylene sensor.
The stimuli-responsive textiles, especially water-responsive textiles, have garnered attention owing to their environmental compatibility. Inspired by the hydrochromic behavior of Diphylleia grayi, water-rewritable structural color (WRSC) textiles exhibiting fast response speed and antispreading capability were fabricated by spraying hollow SiO2 (H-SiO2) microspheres and poly(trifluoroethyl methacrylate-butyl acrylate) [P(TFEMA-BA)]. The water-written textiles exhibited structural color changes in 0.6 s via an increase in the refractive index, driven by water penetrating the gaps between H-SiO2 microspheres. The structural color was restored to the initial state after the water evaporated, allowing multiple cycles of the write-erase-write mode. The hydrophobic P(TFEMA-BA) adhesive was used to construct a stable chromogenic array and endow WRSC textiles with antispreading properties, thereby improving structural stability and achieving clear writing patterns. The prepared WRSC textiles demonstrated high flexibility, structural stability, and water-rewritable properties, providing advanced bionic inspiration and valuable design ideas for rewritable materials and smart textiles.
危险品化学品经营许可证（带存储）