Laser-Assisted Fabrication of Flexible Micro-Structured Pressure Sensor for Low Pressure Applications

A novel capacitive pressure sensor based on micro-structured polydimethylsiloxane (PDMS) was fabricated for low pressure applications. The pressure sensor was developed using PDMS and silver (Ag) as the dielectric and electrode layers, respectively, on flexible polyethylene terephthalate (PET) substrate. A set of PDMS films with pyramid shaped micro-structures were fabricated using a laser engraved acrylic mold. The electrodes (top and bottom) were fabricated by depositing Ag on PET films using additive screen-printing process. The pressure sensor was assembled by attaching the top and bottom Ag electrodes to the smooth side of the pyramid shaped micro-structured PDMS (PM-PDMS) films. The top PM-PDMS was then placed on the bottom PM-PDMS. The capability of the fabricated pressure sensor was investigated by subjecting the sensor to pressures ranging from 75-170 Pa. A sensitivity of 0.22%Pa^-1 and correlation coefficient of 0.9722 was calculated for the sensor.