School of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Polymer Materials, South China University of Technology, Guangzhou 510640, China.
School of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Polymer Materials, South China University of Technology, Guangzhou 510640, China.
J Colloid Interface Sci. 2022 Nov 15;626:554-563. doi: 10.1016/j.jcis.2022.06.171. Epub 2022 Jun 30.
In recent years, flexible strain sensors have attracted considerable attention for the great application potential in the emerging fields of wearable devices, electronic skin and health monitoring. However, most of flexible strain sensors are nondegradable, and the produced numerous electronic wastes after uselessness will seriously threaten environment and ecology. Herein, we propose a new strategy to fabricate degradable and stretchable bio-based strain sensor using candle soot (CS) particles to construct conductive pathways and chitosan, potato starch (PS), and polyvinyl alcohol (PVA) to form stretchable matrix in the presence of Fe ions. Owing to the formation of multiple hydrogen bonding constructed by chitosan, PS and PVA as well as coordination bonding by Fe ions, the obtained strain sensor showed high elongation at break up to 200% and good fatigue resistance. Furthermore, the firm embedding of the CS particles into the surface of the stretchable matrix endowed the strain sensor with steady sensitivity (gauge factors of 1.49 at 0-60% strain and 2.71 at 60-100% strain), fast response (0.22 s) and good repeatability even after 1000 stretching-releasing cycles. In addition, the strain sensor was successfully applied to detect various human motions including finger and wrist bending, swallowing and pronunciation. Interestingly, after connecting to an Arduino microcontroller circuit with a Bluetooth module, the strain sensor was able to wirelessly detect real-time movements of index finger joints. Different from most previously reported sensors, the prepared strain sensor in this work was completely degraded in 2 wt% CHCOOH solution at 90 °C only within 10 min, thus effectively avoiding the production of electrical waste after the updating and upgrading of the sensors. The findings conceivably stand out as a new methodology to prepare environmental-friendly sensors in the field of flexible electronics, which is very beneficial for the sustainable development of environment and society.
近年来，柔性应变传感器因其在可穿戴设备、电子皮肤和健康监测等新兴领域的巨大应用潜力而引起了广泛关注。然而，大多数柔性应变传感器是不可降解的，而且无用之后产生的大量电子垃圾将严重威胁环境和生态。在此，我们提出了一种使用烛黑（CS）颗粒构建导电通路、壳聚糖、马铃薯淀粉（PS）和聚乙烯醇（PVA）在 Fe 离子存在下形成可拉伸基质的新策略来制备可降解和可拉伸的生物基应变传感器。由于壳聚糖、PS 和 PVA 形成的氢键和 Fe 离子形成的配位键的多重作用，所制备的应变传感器具有高达 200%的断裂伸长率和良好的耐疲劳性。此外，CS 颗粒牢固地嵌入到可拉伸基质的表面，使应变传感器具有稳定的灵敏度（在 0-60%应变时的灵敏度系数为 1.49，在 60-100%应变时为 2.71）、快速响应（0.22s）和良好的可重复性，即使在 1000 次拉伸-释放循环后也是如此。此外，该应变传感器成功应用于检测各种人体运动，包括手指和手腕弯曲、吞咽和发音。有趣的是，将应变传感器连接到带有蓝牙模块的 Arduino 微控制器电路后，它能够无线检测食指关节的实时运动。与大多数以前报道的传感器不同，在 90°C 的 2wt%CHCOOH 溶液中，本工作中制备的应变传感器仅在 10 分钟内完全降解，从而有效地避免了传感器更新和升级后产生的电子废物。这一发现为在柔性电子领域制备环保型传感器提供了一种新的方法，这对环境和社会的可持续发展非常有益。
