Sujeesh Vishnu, Ponraj Godwin, Ren Hongliang
Department of Biomedical Engineering, National University of Singapore, Singapore 117575, Singapore.
Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong.
Micromachines (Basel). 2022 Jan 18;13(2):146. doi: 10.3390/mi13020146.
Ionic pressure sensors are made of ionic compounds suspended in a suitable solvent mixture. When external pressure is exerted on them, it is reflected as a change in electrical parameters due to physical deformation and a redistribution of ions within the sensing medium. Variations in the composition and material of the sensing medium result in different pressure sensors with varying operating ranges and sensitivity. This work presents the design and fabrication procedure of a novel soft-pressure sensor for a very low-pressure range (<20 mm Hg) using Aloe vera gel and Glycerin as the solvent for the ionic sensing medium. We also provide a comparative study on the performance of sensor prototypes with varying solvent concentrations and geometric parameters based on a series of characterization experiments. Maximum sensitivity (7.498×10-4 Ω/mmHg) was observed when using 40% glycerin in the sensing medium, filled in a toroidal geometry with outer and inner channel diameters of 8 mm and 7 mm, respectively. The proposed sensor is entirely soft and can be designed to conform to any desired geometry.
离子压力传感器由悬浮在合适溶剂混合物中的离子化合物制成。当外部压力施加于其上时，由于物理变形以及传感介质内离子的重新分布，它会表现为电参数的变化。传感介质的成分和材料变化会导致不同的压力传感器，其工作范围和灵敏度各异。这项工作展示了一种新型软压力传感器的设计与制造过程，该传感器用于极低压力范围（<20毫米汞柱），使用芦荟凝胶和甘油作为离子传感介质的溶剂。我们还基于一系列表征实验，对具有不同溶剂浓度和几何参数的传感器原型的性能进行了比较研究。当在传感介质中使用40%的甘油，填充到环形几何结构中，其外通道直径和内通道直径分别为8毫米和7毫米时，观察到了最大灵敏度（7.498×10-4Ω/mmHg）。所提出的传感器完全柔软，并且可以设计成符合任何所需的几何形状。
