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Description
This study explores developing and applying a linear position sensor leveraging bistable microwire technology. Bistable microwires offer a unique advantage in sensor design because they can detect multiple physical quantities with high sensitivity through simple electronic configurations. It is even possible to separate the external magnetic field’s contribution, which opens up the opportunity to measure in various magnetic environments.
Using all the advantages of bistable microwire, it is possible to design a linear position sensor with high resolution. The core of this measurement system relies on the bistable microwire, excited by an alternating magnetic field generated by an excitation coil. The microwire response signal is subsequently captured by a sensing coil, which is processed by an STM32 microcontroller.
With the presented unique approach, it is possible to transfer the linear position of the piston into the switching time and obtain high sensitivity down to 1 $\mu$m, representing a very high resolution. Additionally, it was found that the device is resistant to temperature effects, giving it an advantage over other linear displacement sensors.
Fig. 1 Theoretical current and magnetic field strength characterization depends on the distance (left), and the real characteristic of the switching time depends on the distance (right).
Acknowledgements
This work was partially supported by Slovak Grant Agencies VEGA 1/0053/19 and APVV-16-0079.
References
[1] P. Jacko, R. Jurč, L. Galdun, Ľ. Hvizdoš, D. Kováč, and R. Varga, “Linear position sensor using magnetically bistable microwire,” Sensors and Actuators A: Physical, vol. 349. Elsevier BV, p. 114017, Jan. 2023. doi: 10.1016/j.sna.2022.114017.
