A novel torsion testing technique for micro-scale specimens based on electromagnetism.

Area of Science:

• Materials Science
• Mechanical Engineering
• Electromagnetism

Background:

• Micro-scale materials require specialized testing techniques.
• Existing torsion testing methods may lack precision for minute specimens.

Purpose of the Study:

• To develop and validate a novel electromagnetic torsion apparatus for micro-scale specimens.
• To assess the performance and calibration of the new apparatus.

Main Methods:

• Utilized a coil-magnet component for actuation and torque measurement based on Ampere force.
• Employed a laser displacement sensor for precise rotation angle measurement.
• Calibrated torque measurements using a Sartorius BP211D balance.

Main Results:

• Demonstrated a perfect linear relationship between applied current and measured torque.
• Achieved a torque capacity of 4.0 × 10⁻⁴ N·m with a noise floor below 10⁻⁸ N·m.
• Attained a rotation angle capacity of 60° with a noise floor below 0.02°.

Conclusions:

• The novel torsion apparatus is effective for micro-scale specimens.
• Experimental results on copper wires showed good resolution and repeatability.
• The developed technique advances torsion testing capabilities for micro-materials.