Chinese Scientists Develop Tiny Sensor That Redefines Vacuum Pressure Measurement

A research team from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences has unveiled a revolutionary microsensor that dramatically improves the accuracy and range of vacuum pressure measurement—key to applications in semiconductor manufacturing, space missions, and high-precision engineering.

Led by Professors CHEN Deyong and WANG Junbo, the team developed a novel micro-electromechanical systems (MEMS) pressure sensor that operates seamlessly across six orders of magnitude (from 0.3 Pa to 100,000 Pa) using just a single sensing element. Their findings were published in Microsystems & Nanoengineering.

"This sensor breaks through a long-standing barrier in vacuum measurement," said Prof. Wang Junbo. "We have not only achieved a wide measurement range in a miniature device, but also ensured high accuracy and stability even under extreme temperatures."

Wide-range vacuum sensors are essential in many high-tech environments. In the semiconductor industry, for example, precise pressure control is critical for processes like chemical vapor deposition and plasma etching. Current sensor technologies, however, are forced to trade off between range and accuracy. Pirani gauges can measure a wide range but lack precision, while capacitance diaphragm gauges (CDGs) are highly accurate but limited in range. Composite sensors combine both but are large, complex, and sensitive to the type of gas being measured.

The MEMS sensor developed by the AIR team avoids these trade-offs by integrating two operating modes of resonators into a single chip. At low pressures (0.3 Pa–1,000 Pa), it uses a "mode-localizatio" mode that amplifies tiny changes in pressure into easily detectable signals. At higher pressures (1,000 Pa–100,000 Pa), it automatically switches to a traditional resonance mode, which is highly accurate and stable.

This dual-mode approach results in exceptional performance. The sensor achieves a resolution of approximately 0.1 Pa in low-pressure environments and 2.0 Pa at higher pressures. Calibration errors are minimal—just 1.99% relative deviation at 120 °C in low pressure, and as low as 0.01% full scale in high pressure. It also performs reliably across a broad temperature range from –20 °C to 120 °C and is unaffected by different gas types.

All of this functionality is housed in a compact MEMS chip just 27.2 mm³ in size—dramatically smaller than conventional commercial sensor chips, which can be over 200 times larger. That compactness, combined with its high performance and gas-type independence, makes the new sensor a powerful alternative to traditional technologies.

"This innovation is more than a new sensor—it's a paradigm for the next generation of precision measurement," added Prof. Wang.