Liangshutong Zhang,Yupu Zhang,Xinyu Li,Donghao Han,Wei Zhai,Jianyuan Wang
The realization of fast, simple and efficient flight attitude recognition is crucial for flight safety and control stability, but still faces challenges in new materials and technologies. Herein, a chloroplast-like selenium-doped copper sulfide@black phosphorus (CSS@BP) composite material is prepared by ultrasonic chemical synthesis using BP nanosheets to effectively absorb light energy and disperse CSS layers to promote rapid photothermal conversion, which shows the temperature change more than ≈40 °C and an excellent photothermal conversion efficiency of 68.9% at 405 nm, corresponding to the theoretical calculation results. Moreover, the CSS@BP/Bi 2 Te 3 photothermoelectric conversion array prepared by pulsed laser deposition coated Bi 2 Te 3 thermoelectric layer and laminated porous insulating polyimide film can generate rapid thermal current changes through irradiated/non-irradiated thermal gradients. Hence, a portable attitude recognition box (ARB) is assembled with a based CSS@BP/Bi 2 Te 3 array with a self-balancing laser and a current measurement chip that enables accurate attitude recognition through the bidirectional current generated by changes of irradiated area. Excitably, the ARB demonstrates over 86.47% accuracy without complex algorithms, showing excellent stability and robustness. Thus, this work offers an innovative solution for advancing photothermal materials and low-cost high-precision flight attitude sensing technologies.
Flexible piezoelectric energy harvesters (FPEHs) made of polymer-based piezoelectric composites are urgently needed for powering wearable electronics. Employing water-based freeze casting and emulsion-template method, a porous structured Barium titanate(BaTiO 3 )/PDMS composite is obtained, which combines the piezoelectric ceramics with piezoelectric electret. For the BaTiO 3 ceramic skeletons, three different pore arrangements are obtained by utilizing flat-bottomed mold, wedge-shaped mold and round-table mold. The ceramic skeletons are then encapsulated with the PDMS matrix with and without porous forming ingredient. Finite element simulation is carried out to reveal the influence of the alignment of BaTiO 3 skeleton and porous PDMS on the piezoelectric behavior. The output performance is investigated for the BaTiO 3 /PDMS composite upon a vibration exciter, as well as human motion. It is found that the BaTiO 3 skeleton with a scattered porous structure aligned in the horizontal direction, encapsulated with a porous PDMS possesses the most prominent output voltage and power, reaching 6.63 V and 26.46 μW, respectively upon a compressive load of 21 N at 8 Hz. Moreover, a smart insole based on the porous structured BaTiO 3 /PDMS piezocomposites with both energy harvesting and posture recognition functions is constructed. The open-circuit voltage of the smart insole reachs 40 V in jumping states, and can successfully power an alarm clock. The study offers a new approach for designing of the flexible piezoelectric composites for applications in energy harvesting and posture recognition.
Achieving human skin-like sensitivity and wide-range pressure detection remains a significant challenge in the development of wearable pressure sensors. In this study, we engineered and fabricated a fibrous polyimide fiber (PIF)/carbon nanotube (CNT) composite aerogel with a gradient structure using a layer-by-layer freeze casting technique, aiming to overcome the limitations of traditional pressure sensors. Finite element analysis (FEA) reveals that this innovative gradient structure mimics the unique microstructure of human skin, enabling the sensor to detect a broad spectrum of pressure stimuli, ranging from subtle pressures as low as 10 Pa to intense pressures up to 1.58 MPa with exceptional sensitivity. Moreover, the sensor exhibits extraordinary pressure resolution across the entire pressure range, particularly at 1 MPa (0.001%). Additionally, the sensor demonstrates remarkable thermal stability, operating reliably across a wide temperature range from − 150 to 200 °C, making it suitable for extreme environments such as deep space exploration. When integrated with machine learning algorithms, the sensor shows great potential for real-time physiological monitoring, fitness tracking, and motion recognition. The proposed gradient fibrous pressure sensor, with its high sensitivity and resolution over a wide pressure range, paves the way for new opportunities in human–machine interaction. Graphical abstract
危险品化学品经营许可证（带存储）