Li Yida, Nayak Suryakanta, Luo Yuxuan, Liu Yijie, Salila Vijayalal Mohan Hari Krishna, Pan Jieming, Liu Zhuangjian, Heng Chun Huat, Thean Aaron Voon-Yew
Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore.
Institute of High Performance Computing, A*STAR Research Entities, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore.
Materials (Basel). 2019 May 6;12(9):1458. doi: 10.3390/ma12091458.
We report on the dual mechanical and proximity sensing effect of soft-matter interdigitated (IDE) capacitor sensors, together with its modelling using finite element (FE) simulation to elucidate the sensing mechanism. The IDE capacitor is based on liquid-phase GaInSn alloy (Galinstan) embedded in a polydimethylsiloxane (PDMS) microfludics channel. The use of liquid-metal as a material for soft sensors allows theoretically infinite deformation without breaking electrical connections. The capacitance sensing is a result of E-field line disturbances from electrode deformation (mechanical effect), as well as floating electrodes in the form of human skin (proximity effect). Using the proximity effect, we show that spatial detection as large as 28 cm can be achieved. As a demonstration of a hybrid electronic system, we show that by integrating the IDE capacitors with a capacitance sensing chip, respiration rate due to a human's chest motion can be captured, showing potential in its implementation for wearable health-monitoring.
我们报告了软物质叉指式(IDE)电容传感器的双重机械和接近感应效应,并通过有限元(FE)模拟对其进行建模以阐明传感机制。该IDE电容基于嵌入聚二甲基硅氧烷(PDMS)微流体通道中的液相镓铟锡合金(Galinstan)。使用液态金属作为软传感器的材料理论上允许无限变形而不会破坏电连接。电容传感是电极变形引起的电场线干扰(机械效应)以及人体皮肤形式的浮动电极(接近效应)的结果。利用接近效应,我们表明可以实现高达28厘米的空间检测。作为混合电子系统的演示,我们表明通过将IDE电容器与电容传感芯片集成,可以捕获由于人体胸部运动引起的呼吸速率,显示出其在可穿戴健康监测中的应用潜力。