School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Nanoscale. 2017 Nov 16;9(44):17396-17404. doi: 10.1039/c7nr05106a.
Nanocomposite strain sensors composed of compressed honeycomb-like reduced-graphene-oxide (RGO) foam embedded in polydimethylsiloxane are facilely fabricated via unidirectional freeze-drying and simple mechanical compression. The microstructural characteristics of the nanocomposites endow the sensors with excellent flexibility, high stretchability and sensing sensitivity, as well as anisotropic mechanical and sensing performance when stretched along directions vertical and parallel to the aligned RGO cell walls (defined as transverse and longitudinal directions, respectively). In particular, the compression of the aligned RGO foam into a thinner film results in more conductive pathways, greatly increasing the sensing sensitivity of the nanocomposite sensors. The sensors stretched along the transverse direction show an outstanding combination of high stretchability over 120%, wide linear sensing region of 0-110% and high strain sensing sensitivity with a gauge factor of around 7.2, while even higher strain sensitivity and lower sensing strain are exhibited along the longitudinal direction. Sensitive and reliable detection of human motions is also successfully demonstrated using these light-weight thin-film nanocomposite sensors.
由压缩的蜂窝状还原氧化石墨烯（RGO）泡沫嵌入聚二甲基硅氧烷制成的纳米复合应变传感器可通过单向冷冻干燥和简单的机械压缩轻松制造。纳米复合材料的微观结构特征赋予传感器出色的柔韧性、高拉伸性和传感灵敏度，以及在垂直和平行于定向 RGO 细胞壁（分别定义为横向和纵向）拉伸时的各向异性机械和传感性能。特别是，将定向 RGO 泡沫压缩成更薄的薄膜会导致更多的导电通路，从而大大提高纳米复合传感器的传感灵敏度。沿横向拉伸的传感器具有出色的综合性能，拉伸率超过 120%，线性传感区域为 0-110%，应变传感灵敏度高，其灵敏系数约为 7.2，而沿纵向则表现出更高的应变灵敏度和更低的传感应变。使用这些重量轻的薄膜纳米复合传感器还成功地演示了对人体运动的敏感可靠检测。
