KAUST team develops micron-level, low-power pressure sensors

[ Instrument Network Instrument R & D ] According to foreign media reports, recently, scientists at KAUST developed a micron-level, low-power pressure sensor that has potential application prospects in a vacuum environment.

The pressure sensor designed by this group has a wide working range and high sensitivity.

Today, sensors are the interface between automation systems such as computers and robots and their environment. Sensors measure light, temperature, motion, mass, pressure, location, etc. The current market and application demand for sensors is to make them smaller so that they can be integrated into portable products. For example, pressure sensors can be used in industrial control, healthcare, medical testing, and meteorology. Depending on the application, these pressure sensors need to be sensitive to small changes, respond quickly to these changes, and be able to work over a large pressure range.

Now, Nouha Alcheikh, Amal Hajjaj, and Mohammad Younis have developed a sensitive pressure microsensor based on a silicon vibrating beam that is only 800 microns long, 25 microns wide, and 1.5 microns thick. "We have developed a scalable and sensitive micro-pressure sensor that can operate over a larger pressure range in nanosystems," Alcheikh said.

In experimental studies, the cantilever will vibrate at a resonance frequency, which is determined by its mass, length, density, and stiffness. As current passes through the vibrating beam, it becomes hotter and begins to bend. This increased curvature increases the stiffness of the vibrating beam, thereby shifting the resonant frequency. The air around the vibrating beam cools it: the higher the pressure, the more air, the better the cooling effect. Therefore, the resonance frequency of a vibrating beam that can be measured electrically is related to pressure. The device manufactured by the team works over a wide range of pressures, from 0.038 Torr to 200 Torr (atmospheric pressure is 760 Torr), and the sensitivity of the pressure sensor is 2689 x 10-6 / Torr.

The research team also showed that this pressure microsensor can be adapted to specific applications by changing the thickness of the vibrating beam. They simulated the operation of a vibrating beam to prove that for thinner micro-vibrating beams, sensitivity becomes higher, but thicker vibrating beams consume more energy. Therefore, the thickness of the sensitivity under low or high pressure can be calculated according to the target environment of the device.

"Thanks to KAUST's advanced facilities, we are fortunate to be able to explore new ideas, such as this novel pressure sensor. I hope to continue to take this opportunity to commercialize this device concept," Alcheikh said.