This Novel Thin-Film Sensor Measures High-Speed Airflow — Without Disturbing It

Researchers at the Tokyo University of Science, Iwate University, and Mitsubishi Heavy Industries have developed a new sensor which could help improve machinery used in the energy generation and transport sectors — by flexing across curved surfaces, like fan blades, to measure high-speed airflow accurately.

"Sensing the shear stress and its direction on curved surfaces, where flow separation easily occurs, has been difficult to achieve in particular without using a novel technique," explains Masahiro Motosuke, professor at the Tokyo University of Science, of the problem his team sought to solve.

The team's proposed solution: a microelectromechanical system (MEMS) sensor, built on a soft substrate, which is thin and flexible enough to be applied to curved surfaces. Integrating a micro-heater and six temperature sensors arranged in an array around it, the sensor is capable of measuring wall shear stress and flow angle — and by adjusting the position of the circuits surrounding the sensor, disruption to the measured flow is kept to a minimum.

The researchers are hopeful that the sensor could find a use for improving the efficiency of industrial-scale fluid machinery used in energy generation and transportation — though it needs additional work first. "Although this sensor is designed for fast airflows, we are currently developing sensors that measure liquid flow and can be attached to humans based on the same principle," Motosuke explains. "Such thin and flexible flow sensors can open up many possibilities."

The team's work has been published under open-access terms in the journal Micromachines following its presentation at the 12th Symposium on Micro-Nano Science and Technology.

Main article image courtesy of Masahiro Motosuke, TUS.