Micromechanical Force Sensor Using the Stress-Impedance Effect of Soft Magnetic FeCuNbSiB

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• The stress-impedance (SI) effect in soft magnetic amorphous alloys offers potential for transducer applications.
• Investigating the SI effect in thin films is crucial for micro-device development.
• FeCuNbSiB alloys are known for their magnetic properties, but their thin-film SI behavior requires further study.

Purpose of the Study:

• To fabricate and characterize a micromachined force sensor using the SI effect of a FeCuNbSiB amorphous alloy thin film.
• To elucidate the SI effect mechanism in this specific thin-film material.
• To evaluate the sensor's performance, particularly its gauge factor, for potential tactile sensing applications.

Main Methods:

• Fabrication of a force sensor using a 500 nm sputtered FeCuNbSiB thin film.
• Characterization of magnetic and mechanical properties of the thin film.
• Measurement of the stress-impedance (SI) effect and gauge factor (GF).

Main Results:

• The sputtered FeCuNbSiB thin film exhibited a significant SI effect, attributed to stress-dependent magnetic permeability.
• The material demonstrated a high yield strength of 983 GPa.
• The fabricated sensor achieved a gauge factor (GF) of 756, substantially exceeding conventional piezoresistive sensors.

Conclusions:

• A simple fabrication process yielded a high-performance force sensor based on the SI effect in FeCuNbSiB thin films.
• The sensor's high GF indicates superior sensitivity compared to traditional transducer effects.
• The developed device shows promising potential for integration into tactile sensing systems.