A novel of fluidic based one side electrode type pressure sensor

Abstract

This paper presents the development of the novel fluidic based one side electrode pressure sensor. The structure of the sensor consists of container and an electrode. For the container, the membrane and microchannel were combined in one structure. Meanwhile, the design of the electrode was extended from the pattern of coplanar electrode based on the previous study. The microfluidic technology by using a small amount of liquid as a sensing element was proposed to measure the external pressure. When the external pressure was applied to the sensor, the membrane was deflected and the liquid displaced inside the microchannel. The sensing electrode measured the changes using electrical double layer concepts and gave the output in capacitance. The sensor was successfully fabricated for electrode using printed circuit board (PCB) process and the container using polymer fabrication process. The polymer such as PDMS was chosen because it was suitable to be implemented as a membrane. The methanol was used as a liquid due to its dielectric constant. The data experiment was recorded and measured using LCR meter for different applied pressure. The capacitance response was demonstrated for pressure 2kPa until 30kPa. The sensitivity of the sensor was 0.06pF/kPa. Also, the standard deviation of output capacitance equaled to 0.04.