A Wireless Passive Pressure-Sensing Method for Cryogenic Applications Using Magnetoresistors.
Ziqi Zhao1, Michitaka Yamamoto1, Seiichi Takamatsu1
1Department of Precision Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
Sensors (Basel, Switzerland)
|February 10, 2024
Summary
We developed a new wireless, passive pressure sensor for cryogenic temperatures. This robust, low-cost sensor uses a magnetoresistor and backscattering antenna for reliable remote pressure monitoring at -196 °C.
Area of Science:
- Cryogenic Engineering
- Wireless Sensor Technology
- Materials Science
Background:
- Traditional cryogenic pressure sensors face challenges due to poor low-temperature tolerance and complex wiring for power and data.
- Existing methods require cumbersome setups, limiting their application in extreme cold environments.
Purpose of the Study:
- To develop a novel wireless, passive pressure-sensing method specifically for cryogenic temperatures (-196 °C).
- To overcome the limitations of conventional sensors in extreme cold environments.
- To enable simple, robust, and cost-effective pressure monitoring in cryogenics.
Main Methods:
- Integration of a low-temperature-tolerant magnetoresistor (MR) onto a backscattering antenna.
- Utilizing the pressure-induced displacement between the MR and a magnet to modulate antenna return loss.
- Employing a wireless backscattering technique for passive data acquisition.
Main Results:
- The fabricated sensor successfully detected varying pressures at both room temperature (24 °C) and cryogenic temperature (-196 °C).
- Achieved high sensitivities of 4.3 dB/MPa (room temperature) and 1.3 dB/MPa (cryogenic temperature).
- Demonstrated the capability for simultaneous wireless readings of multiple sensors by frequency band separation.
Conclusions:
- The developed method offers a low-cost, simple, robust, passive, and wireless solution for pressure measurement at -196 °C.
- This technology is highly desirable for various cryogenic applications requiring reliable pressure monitoring.
- The sensor's design overcomes the limitations of existing technologies in extreme cold environments.
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