Fabrication of fluidic based capacitive pressure sensor using printed circuit board and soft lithography process

Abstract

This paper describes the process of developing a device with planar electrode sensor using capacitance measurement. The project investigate the feasibility and characterization of planar pressure sensor integrated on a polydimethylsiloxane (PDMS) channel. A 2-planar electrodes, with each dimension of the electrode, 50 mm × 4 mm (length x width) and the gap between 2 electrodes was 0.4 mm was fabricated using a printed circuit board (PCB) technology due to its low cost advantage. The PDMS channel was bonded on the PCB with cured to create a rectangular shape sensing for loading the pressure. The mold of PDMS channel was develop by designed using Autodesk Inventor 2017 and was fabricated using a 3D printer. Capacitance measurement of the planar electrodes was carried out using water and ethanol as the sample that inside the channel. Experimental result shows that the measured electrodes are ethanol and water, linear proportional to the capacitance value. The value of ethanol is higher that the water which was the range was 11 pF to 13pF for ethanol and for the water was 9 pF to 10pF. The result shows that the planar sensors are able to provide capacitance measurement within the device platform where, the ethanol value provide larger output as compared to the water value.