College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering , Sichuan University , Chengdu 610065 , P. R. China.
ACS Appl Mater Interfaces. 2018 Sep 19;10(37):31655-31663. doi: 10.1021/acsami.8b11766. Epub 2018 Sep 6.
Stretchable and wearable sensors with active response to various environmental stimuli possess numerous potential applications in stretchable electronics, motion sensors, environmental monitoring, and so on. Herein, we report a new method to realize control on the local conductive networks of strain sensors, thus, their sensing behavior. These multifunctional crack-based sensors were prepared via spray coating a mixture of carbon nanotube (CNT) and 3-aminopropyltriethoxysilane (KH550) with various ratios onto polydimethylsiloxane (PDMS). The conductive CNT/KH550 layer exhibits brittle mechanical behavior which triggers the formation of cracks upon stretching. This is thought to be responsible for the observed electromechanical behavior. These sensors exhibit adjustable gauge factors of 5-1000, stretchability (ε) of 2-250%, linearity (nonlinearity-linearity) and high durability over 1000 stretching-releasing cycles for mechanical deformation. Washable, wearable, and water-repellent sensors were prepared through such a method to successfully detect human physiological activities. Moreover, the variation in temperature or the presence of solvent can also be detected due to the thermal expansion and swelling of the PDMS layer. It is expected that such a concept could be used to prepare sensors for multiple applications, thanks to its multifunctionality, adjustable and robust performance, simple and low-cost fabrication strategy.
具有对各种环境刺激主动响应的可拉伸和可穿戴传感器在可拉伸电子产品、运动传感器、环境监测等方面具有众多潜在应用。在此，我们报告了一种新方法，可实现对应变传感器局部导电网络的控制，从而控制其传感行为。这些基于裂纹的多功能传感器是通过喷涂 CNT 和 3-氨丙基三乙氧基硅烷（KH550）以不同比例混合的混合物到聚二甲基硅氧烷（PDMS）上来制备的。导电 CNT/KH550 层表现出脆性机械行为，在拉伸时会引发裂纹的形成。这被认为是导致观察到的机电行为的原因。这些传感器表现出可调节的应变系数为 5-1000，拉伸性（ε）为 2-250%，线性度（非线性-线性）和超过 1000 次拉伸-释放循环的高耐用性，用于机械变形。通过这种方法制备了可水洗、可穿戴和防水的传感器，成功地检测了人体生理活动。此外，由于 PDMS 层的热膨胀和溶胀，还可以检测温度变化或溶剂的存在。由于其多功能性、可调节和稳健的性能以及简单而低成本的制造策略，预计这种概念可用于制备多种应用的传感器。
