Application of a piezo-electric actuator to tamper resistant recessless screws

Screws with a cross- or minus- shaped recess on their head are very widely used in a variety of machines because of their ease of use and very high joint force. However, their ease of use makes them unsuitable for applications requiring tamper resistant fasteners (TRF). As a way to realize a highly secure TRF, this paper proposes recess-less screws and a piezo-electric screwdriver (PZSD). The principle of the proposed screwdriver is very similar to that of the ultrasonic motor, which uses piezo-electric cells to generate rotational motion. In this paper, the performance of the PZSD is evaluated based on experiments.