Abstract: A clutch based on voltage-controlled friction phenomenon was designed and manufactured to examine the clutch characteristics and the response of the friction torque of a brass/silicon nitride rubbing pair to the external potential. Thus the effect of the external potential on the friction behavior of the brass/silicon nitride pair was examined under the lubrication of saturated sodium laurylsulfonate, with the brass plate to be the cathode and four graphite plates connected to the brass plate as the anodes. It was found that the output torque and friction coefficient of the frictional pair was changed by a factor of 2 upon the applying of 20 V external voltage. The response time of the friction to an external square-wave voltage was about 2~5 s at the rising stage and about 3~8 s at the dropping stage. It was therefore supposed that the voltage-controlled friction technology could be applied to friction transmission.