Corrugated Glass Diaphragm Differential Pressure Sensor Using Sampling Moiré Method

Various types of pressure sensors have been developed because pressure monitoring is essential in a variety of fields. Among these, optical methods have attracted attention due to their high sensitivity and low drift; however, they often require complex setups. Recently, the sampling Moiré (SM) method has emerged as an optical measurement technique, offering both simplicity and high resolution. In this letter, we propose a vision-based differential pressure sensor using the SM method. The proposed sensor consists of a corrugated glass diaphragm with a stripe pattern, a right-angle prism, and a microcontroller-based board camera. From the images of the stripe pattern captured before and after diaphragm displacement, the applied differential pressure is calculated using the SM method. We designed and fabricated a corrugated glass diaphragm with a thickness of 50 µm using laser processing. A stripe pattern with a pitch of 0.4 mm was formed at the center of the diaphragm. Then, the sensor was fabricated by assembling the corrugated glass diaphragm, the prism, and the camera. The pressure calibration experiments were conducted to evaluate the sensor response. When a differential pressure of −200 to +200 Pa was applied to the sensor, the measured displacement was linear, with a resolution of less than 10 Pa. These results suggest that the proposed vision-based sensor can effectively measure differential pressure with a simple setup.