New non-contacting torque sensor based on the mechanoluminescence of ZnS:Cu microparticles

• The use of mechanoluminescence (ML) enables us to measure the rotating shaft torque.
• ML intensity decay issue has been resolved using a new microparticle (ZnS:Cu).
• This study provides potential applications for new non-contacting torque sensor.

This paper presents a preliminary study investigating the development of a new type of non-contacting torque sensor based on the mechanoluminescence (ML) of a new microparticle (ZnS:Cu), which is intended to address the ML intensity decay present in a previous prototype torque measurement system with a conventional microparticle (SAO). An ad hoc heuristic model of hysteresis is proposed to characterize the loading rate-dependent characteristics of the ML intensity emitted from ZuS:Cu microparticle, and to estimate the torque input. The sinusoidal torque applied to a rotational shaft is successfully measured with a small error range by sensing the ML intensity without contacting. This study provides potential applications for the development of new non-contacting torque sensing technology widely used in various industrial areas such as automotives, robotics, rotors, and turbines.