title: Highly stable liquid metal-based pressure sensor integrated with a microfluidic channel.
abstract: Pressure measurement is considered one of the key parameters in microfluidic systems. It has been widely used in various fields, such as in biology and biomedical fields. The electrical measurement method is the most widely investigated; however, it is unsuitable for microfluidic systems because of a complicated fabrication process and difficult integration. Moreover, it is generally damaged by large deflection. This paper proposes a thin-film-based pressure sensor that is free from these limitations, using a liquid metal called galinstan. The proposed pressure sensor is easily integrated into a microfluidic system using soft lithography because galinstan exists in a liquid phase at room temperature. We investigated the characteristics of the proposed pressure sensor by calibrating for a pressure range from 0 to 230 kPa (R2 > 0.98) using deionized water. Furthermore, the viscosity of various fluid samples was measured for a shear-rate range of 30-1000 s(-1). The results of Newtonian and non-Newtonian fluids were evaluated using a commercial viscometer and normalized difference was found to be less than 5.1% and 7.0%, respectively. The galinstan-based pressure sensor can be used in various microfluidic systems for long-term monitoring with high linearity, repeatability, and long-term stability.
authors.affiliation: Department of Medical System Engineering, GIST, Gwangju 500-712, Korea. taekeonjung@gist.ac.kr.
authors.forename: Taekeon
authors.initials: T
authors.lastname: Jung
authors.affiliation: Department of Medical System Engineering, GIST, Gwangju 500-712, Korea. syang@gist.ac.kr.|School of Mechatronics, GIST, Gwangju 500-712, Korea. syang@gist.ac.kr.
authors.forename: Sung
authors.initials: S
authors.lastname: Yang
mesh_terms: D000497:Alloys / Q000737:chemistry*; D002138:Calibration; D004867:Equipment Design; D019216:Metals, Heavy / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D011312:Pressure; D014783:Viscosity
chemical_list: D000497:Alloys; D019216:Metals, Heavy; C400133:galinstan
keywords: galinstan; liquid metal; microfluidic; pressure sensor; viscosity