Elastic thermoelectric generators

Recent advances in flexible flow sensors and applications

<p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="first" dir="auto" id="d10035796e161">Drawing inspiration from natural creatures that utilize flow fluctuations to evade predators and track prey, our human beings harness insights into flow dynamics through the development of flow sensors. The past few decades have witnessed a significant development in such sensors, evolving from bulky catheters designed for industrial settings to miniaturized, versatile and flexible devices tailored for wearable scenarios. This work presents a comprehensive overview of recent advances in flexible and thin-film-based flow sensors. First, the primary working mechanisms of these sensors, including thermal, piezoresistive, piezoelectric, and acoustic principles, are introduced, highlighting their challenges and alternative solutions. Subsequently, applications are categorized and demonstrated based on the type of flow including airflow, blood flow, breath, and water flow. Finally, future trends in flexible flow sensors are explored, indicating their pivotal roles in wide research and industry fields such as underwater robotics, human-machine interfaces, and bioelectronics. </p>

Self-confined electrohydrodynamic printing on micro-structured substrate for flexible transparent electrodes with embedded metal mesh

<p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="first" dir="auto" id="d10034240e234">Flexible transparent electrodes (FTEs) have attracted much attention due to their advantages of excellent optical/electrical conductivities and good mechanical fatigue strength. However, their fabrication presents several challenges, including fabricating wires with a high aspect ratio and sufficient tensile resistance. In this study, an embedded Ag/Cu metal-mesh FTE with a high figure of merit 24,708 (sheet resistance 0.08 Ω/sq and 83.4% optical transmittance) is fabricated through the proposed method called self-confined electrohydrodynamic printing and selective electroplating of Cu. This method employs structured surfaces and patterned hydrophilic/hydrophobic properties to enable highly controllable deposition of solutions (e.g., positioning, line width, consistency), allowing the complete filling of imprinted microgrooves with a high aspect ratio of 2 (e.g., 4 μm width and 8 μm depth) with Ag/Cu metal. Moreover, the resulting FTEs demonstrate good resistance stability under repetitive bending and stretching and exhibit excellent performance in flexible transparent heaters and electromagnetic shielding films. </p>