Next Article in Journal
Two-Color Pixel Patterning for High-Resolution Organic Light-Emitting Displays Using Photolithography
Previous Article in Journal
A 3D-Printed Modular Microreservoir for Drug Delivery
Open AccessArticle

Simple Device to Measure Pressure Using the Stress Impedance Effect of Amorphous Soft Magnetic Thin Film

1
Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
2
Department of Robotics, Tohoku University, 6-6-01, Aza Aoba, Aramaki Aoba-ku, Sendai 980-8579, Japan
*
Author to whom correspondence should be addressed.
Micromachines 2020, 11(7), 649; https://doi.org/10.3390/mi11070649
Received: 8 June 2020 / Revised: 25 June 2020 / Accepted: 25 June 2020 / Published: 30 June 2020
(This article belongs to the Section E:Engineering and Technology)
A simple micro-machined pressure sensor, based on the stress-impedance (SI) effect, was fabricated herein using typical micro-fabrication technologies. To sense pressure, a 1-µm thin, soft magnetic metallic film of FeSiB was sputtered and used as a diaphragm. Its electrical response (impedance change) was measured under pressure in a frequency band from 5 to 500 MHz. A lumped-element equivalent electric circuit was used to separate the impedance of the soft magnetic metal from other parasitic elements. The impedance change clearly depended on the applied pressure. It was also shown that the impedance change could be explained by a change in relative permeability, according to the theory of the SI effect. The radial stress in the diaphragm and the relative permeability exhibited a linear relationship. At a measurement frequency of 200 MHz, the largest sensor response, with a gauge factor of 385.7, was found. It was in the same order as the conventional sensors. As the proposed device is very simple, it has the potential for application as a cheap pressure sensor. View Full-Text
Keywords: magnetic thin film; pressure sensing; stress impedance effect; micro device magnetic thin film; pressure sensing; stress impedance effect; micro device
Show Figures

Figure 1

MDPI and ACS Style

Froemel, J.; Akita, S.; Tanaka, S. Simple Device to Measure Pressure Using the Stress Impedance Effect of Amorphous Soft Magnetic Thin Film. Micromachines 2020, 11, 649.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop