Segment-structured diamond-like carbon films for friction surface of surface acoustic wave linear motor

A surface acoustic wave (SAW) linear motor is a kind of ultrasonic motor, which has many merits such as thin structure, easy installation and so on. The motor, however, has a problem with wear of contact surface due to its driving principle. Diamond-like carbon (DLC) film has been recognized as a wear resistance material. In our research, segment-structured DLC (S-DLC) films were applied to the stator transducer surface. However, exfoliations of the S-DLC films and insufficient driving performance were observed. This paper proposes a new preparing method for the segment structure on the stator transducer and describes the prepared surface. Driving surface abrasion test result and increased driving characteristics are also reported. The reason why the driving performance was improved but not same as that of a conventional SAW linear motor is discussed. Friction coefficients are focused for the discussion.