Ultra-thin glass sheet integrated transparent diaphragm pressure transducer

Abstract

This paper reports an ultra-thin glass sheet diaphragm transducer for measuring pressure. In this paper, we demonstrated the air pressure (0–800mBar) measurement at room temperature and at high temperature (>300°C). The proposed pressure transducer is suited for applications requiring a small size (<1mm2), visibility of the measuring area and both chemical and physical stabilities. The prototype ultra-thin glass sheet (UTGS) integrated all-glass transducer was made by sandwiching a 4 or 6μm thick UTGS between a glass slide with an orifice and a glass slide with a channel. When applying pressure on the inlet of the channel, the UTGS at the orifice was deflected, and the deflection was measured through a video captured by a CCD mounted level difference measurement microscope. The maximum UTGS deflection was approximately 10.53μm, and the response was at least faster than 10Hz at an air pressure condition of 800mbar. A practical sensitivity in the range of 0.0029–0.04105μm/mbar was achieved experimentally, and that makes this transducer suitable for highly sensitive, low-pressure measurement. The pressure measurement function of our transducer was confirmed at 301°C, and after a chemical cleaning process using acetone and piranha solution, the transducer appeared to have no obvious damage. The proposed transducer offers a new method for on-chip air and liquid pressure measurement during direct observation of the measurement point.