i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences (CAS), 398 Ruoshui Road, Suzhou, 215123, P. R. China.
Adv Mater. 2017 Nov;29(43). doi: 10.1002/adma.201702517. Epub 2017 Sep 22.
Superhydrophobic surfaces have shown versatile applications in waterproofing, self-cleaning, drag reduction, selective absorption, etc. The most convenient and universally applicable approach to forming superhydrophobic surfaces is by coating; however, currently, superhydrophobic, smart coatings with flexibility and multiple functions for wearable sensing electronics are not yet reported. Here, a highly flexible multifunctional smart coating is fabricated by spray-coating multiwalled carbon nanotubes dispersed in a thermoplastic elastomer solution, followed by treatment with ethanol. The coatings not only endow various substrate materials with superhydrophobic surfaces, but can also respond to stretching, bending, and torsion-a property useful for flexible sensor applications. The coatings show superior sensitivity (gauge factor of 5.4-80), high resolution (1° of bending), a fast response time (<8 ms), a stable response over 5000 stretching-relaxing cycles, and wide sensing ranges (stretching: over 76%, bending: 0°-140°, torsion: 0-350 rad m ). Moreover, multifunctional coatings with thicknesses of only 1 µm can be directly applied to clothing for full-range and real-time detection of human motions, which also show extreme repellency to water, acid, and alkali, which helps the sensors to work under wet and corrosive conditions.
超疏水表面在防水、自清洁、减阻、选择性吸收等方面具有广泛的应用。形成超疏水表面最方便和通用的方法是涂层；然而，目前还没有报道具有灵活性和多种功能的超疏水智能涂层用于可穿戴传感电子设备。在这里，通过喷涂分散在热塑性弹性体溶液中的多壁碳纳米管，并随后用乙醇处理，制备了一种高度灵活的多功能智能涂层。该涂层不仅为各种基底材料赋予了超疏水表面，而且还可以响应拉伸、弯曲和扭转——这一特性对于柔性传感器应用非常有用。该涂层表现出优异的灵敏度（应变系数为 5.4-80）、高分辨率（弯曲 1°）、快速响应时间（<8 ms）、超过 5000 次拉伸-松弛循环的稳定响应以及广泛的传感范围（拉伸：超过 76%，弯曲：0°-140°，扭转：0-350 rad m）。此外，厚度仅为 1 µm 的多功能涂层可以直接应用于衣物，实现人体运动的全范围实时检测，并且对水、酸和碱也具有极强的排斥性，这有助于传感器在潮湿和腐蚀性条件下工作。
