Abstract
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.
Highlights
The permeability, μ, of soft ferromagnetic materials is influenced by perturbations, such as magnetic field, temperature and strain
A superconducting quantum interference device (SQUID) was used to measure characteristics were linear and the resistivity was determined by the 4-point probe method to be 1.65
The measurement results show a clear dependence of the impedance on the applied pressure
Summary
The permeability, μ, of soft ferromagnetic materials is influenced by perturbations, such as magnetic field, temperature and strain. The change in permeability can be understood by the resulting change in impedance, Z, which is measured with an alternating current The dependence of the complex impedance of a magnetic conductor on the magnetic field is called the magneto-impedance (MI) effect [2,3,4,5] This effect is strong and is widely used to create highly sensitive magnetic field sensors [6,7,8,9]. There are several models to describe this stress-impedance (SI) effect [13,14] This effect has been used to create strain gauges based on wires, ribbons, and thin films [15,16,17,18,19,20]. We present a study of a simple micro-fabricated pressure sensor using thin-film technology based on the SI effect. In contrast to conventional piezoresistive pressure sensors, its fabrication technology is very simple
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
