Novel micro torque measurement method for microdevices

Abstract

A general purpose measurement system has been developed which can measure very low torques of the order of 10-7 N m. The new method proposed here uses wind pressure to apply a load to a turbine attached to the output shaft of a device. It can therefore be used for all rotating microdevices. The use of wind pressure reduces the loss during measurements, and makes it possible to measure low levels of torque easily by simply attaching the turbine to the device. In the present study, the measurement principle of the new system has been verified. The static friction torque was measured by the traditional method of using a thread wound around the motor shaft in order to examine the validity of the proposed method, and a comparison of the two methods with the measured data is presented. In addition, a prototype micromotor, 1.6 mm in diameter, has been fabricated and used to demonstrate that the new system is able to measure torques of the order of 10-7 N m while the motor is in operation.