Highly Transparent and Flexible Iontronic Pressure Sensors Based on an Opaque to Transparent Transition
Highly Transparent and Flexible Iontronic Pressure Sensors Based on an Opaque to Transparent Transition
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基于不透明到透明转变的高度透明且灵活的离子电子压力传感器
DOI：
10.1002/advs.202000348
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发表时间：
2020-05-01
期刊：
影响因子：
15.1
通讯作者：
Guo, Chuan Fei
中科院分区：
文献类型：
--
作者：
Liu, Qingxian;Liu, Zhiguang;Guo, Chuan Fei
人机界面、智能眼镜、触摸屏和一些电子皮肤都需要高度透明和柔性的压力传感元件。柔性压力传感器通常应用微结构或多孔活性材料以提高其灵敏度和响应速度。然而，微结构或小孔将导致器件的高雾度和低透明度，因此在柔性压力传感器或电子皮肤中同时平衡灵敏度和透明度是具有挑战性的。在这里，对于由夹在两个透明电极之间的多孔聚偏二氟乙烯（PVDF）膜组成的电容型传感器，通过用与PVDF具有相同折射率的离子液体填充孔隙来解决挑战，并且膜的透射率在可见光范围内从0大幅提高到94.8%。除了光学匹配之外，由于在介电-电极界面处形成双电层，离子液体还显著提高了信号强度以及灵敏度，并且受益于增塑效应，提高了活性材料的韧性和拉伸性。这种透明和柔性的传感器将在智能窗户、隐形带等方面非常有用。
Human-computer interfaces, smart glasses, touch screens, and some electronic skins require highly transparent and flexible pressure-sensing elements. Flexible pressure sensors often apply a microstructured or porous active material to improve their sensitivity and response speed. However, the microstructures or small pores will result in high haze and low transparency of the device, and thus it is challenging to balance the sensitivity and transparency simultaneously in flexible pressure sensors or electronic skins. Here, for a capacitive-type sensor that consists of a porous polyvinylidene fluoride (PVDF) film sandwiched between two transparent electrodes, the challenge is addressed by filling the pores with ionic liquid that has the same refractive index with PVDF, and the transmittance of the film dramatically boosts from 0 to 94.8% in the visible range. Apart from optical matching, the ionic liquid also significantly improves the signal intensity as well as the sensitivity due to the formation of an electric double layer at the dielectric-electrode interfaces, and improves the toughness and stretchability of the active material benefiting from a plasticization effect. Such transparent and flexible sensors will be useful in smart windows, invisible bands, and so forth.