Ultra-thin glass sheet integrated transparent diaphragm pressure transducer

This paper reports an ultra-thin glass sheet diaphragm transducer for measuring pressure. In this paper, we demonstrated the air pressure (0-800 mBar) measurement at room temperature and at high temperature (>300 °C). The proposed pressure transducer is suited for applications requiring a small size (<1 mm2), 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 6 μm 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 10.53 μm, and the response was at least faster than 10 Hz at an air pressure condition of 800 mbar. A practical sensitivity in the range of 0.0029-0.04105 μm/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.