Nannan Zhou,Nan Wang,Han Wang,Huimin Xie,Yangxi Zhang,Hongrui Ao
Piezoelectric auxetic metamaterials with microstructures hold significant promise for the design of force and tactile sensors. Here, a maskless ultraviolet (UV) lithography-based optical 3D μ-printing with high-resolution, rapid prototyping, and customized fabrication is reported to prepare polyvinylidene difluoride (PVDF)-based flexible piezoelectric sensors. With customized crosslinking for the mixture of PVDF solutions, acrylate resins, and additives, these sensors feature 2D negative Poisson’s ratio (2D-NPR) metamaterial networks and 3D microgrid structures on flexible substrates, offering optimized mechanical and electrical properties. Initially, the 2D-NPR metamaterial networks demonstrate a sensitivity of 2.09 mV/°, and a signal-to-noise ratio (SNR) of 30.87 dB for detecting bending behaviors. Additionally, further mechanical designs on 3D arrayed pyramid-shaped (AP-S) sensors with microgrid structures and electronic code locks composed of this sensor array significantly enhance their versatility in detecting vector loads and gesture codes. Notably, compared to planar PVDF sensors, the performance of this 3D microgrid structure sensor has been significantly improved by 1.53-fold, with a 4.25-fold enhancement for the limits of detection. Moreover, the proposed 2D and 3D sensors provide exceptional temperature stability and hysteresis characteristics. Leveraging machine learning algorithms, these flexible piezoelectric sensors can accurately detect human rehabilitation states, marking significant progress in advanced wearable electronics.
Zi-Rong Li,Tian-Run Lv,Zhenxu Yang,Wen-Hai Zhang,Ming-Jie Yin,Ken-Tye Yong,Quan-Fu An
Stretchable strain sensors have the potential to significantly advance electronic healthcare (E-healthcare). However, current challenges, including a limited detection range, low sensitivity, aggregation of conductive nanoparticles, and the inherent rigidity of conductive polymers within hydrogel matrices, hinder their progress. In our study, we employed a dual approach: we tailored both physical and chemical bond densities and coupled them with conductive polymer nanoparticles. As a result, we developed a stretchable hydrogel strain sensor embedded with a quick response code. This innovation achieved an impressive detection range of up to 1500% and a high gauge factor of 16.6. By modifying the hydrogen bond strength and converting conductive polymer nanoparticles into linear polymer chains, we managed to enhance the sensor's stretchability to 2100%. Moreover, the incorporation of a quick response code enabled the sensor to simultaneously monitor in real-time and encode information. Thus, our sensor emerges as a robust contender for pioneering advancements in E-healthcare, potentially supporting intricate applications like rehabilitation progression tracking.
危险品化学品经营许可证（带存储）