Development of a novel microforce-generating machine based on a force generation method using electromagnetic force

Abstract

Herein, we report the development of a microforce-generating machine using electromagnetic force based on the principles of a Kibble balance to establish microforce traceability for ensuring the reliability of microforce measurements. We proposed a rotary-type microforce-generating machine using a combination of a balancing arm, a coil, and magnets. The microforce was generated through the balancing arm from the electromagnetic torque acting between the coil and magnets. The device eigenvalue, which served as the proportionality factor associated with the magnetic and geometric properties, was evaluated experimentally. The relationships between the eigenvalue and the temperature of the neodymium magnets, the rotation direction of the neodymium magnets, and the inclination of the balancing arm were discussed. The repeatability and reproducibility of the realized microforce were evaluated at force steps of 10 and 20 mN, and they were in the range of 3.8 × 10−5–3.9 × 10−4. We demonstrated that a microforce transducer could be calibrated using the proposed machine.

Micro-force sensing techniques and traceable reference forces: a review

“…There are many micro-force-generating methods based on electromagnetic force. For example, Zhu et al [149] proposed a rotary-type micro-force-generating machine based on the principle of a Kibble balance. An electromagnetic torque generated a traceable micro force via a balancing arm; in a range of 100 µN-20 mN, the repeatability and reproducibility were in the range of 3.8 × 10 −5 -3.9 × 10 −4 .…”

Design of a Linear-Motion Type Microforce Generating Machine Using Electromagnetic Force

“…However, there is a limitation in precise force generation due to mechanical factors such as manufacturing technology and calibration of small weights. Therefore, the Kibble balance [2], [3], initially to measure the Planck constant for the redefinition of the kilogram, opens a new path for microforce measurement [4], [5], [6].…”