Contents I. Introduction
Piezoelectric miniature motors are widely presented in literature [1] –[15]. Some of them comprise a fixed part on which are fixed the piezoelectric transducers and a movable part (slider) placed in contact with the fixed part, so as to be moved by the vibration of the piezoelectric transducers. These piezoelectric motors are not adapted for moving the fixed part on which are fixed the piezoelectric transducers, in particular because the piezoelectric transducers are not suitable to generate a wave in the whole of the fixed part. Other piezoelectric miniature motors (Linear ultrasonic motors) can only move in one direction and do not allow to move objects in a plane. The proposed piezoelectric miniature robot in this paper is inspired by the linear ultrasonic motors with the difference being that there is no slider, the vibrator itself moves as an entire robot in multidirections. Our proposed robot is within the scope of robots that move on a solid substrate (smooth and flat ground) where many designs and mechanisms can be found in literature [16]– [25]. We are interested in the mechanism that uses the propagation of waves to generate motion and then uses the waves to control the direction of motion. Two types of waves are used for propulsion of piezoelectric miniature robots on a solid substrate, the standing wave and the traveling wave. A standing wave bi-directional linearly moving miniature piezoelectric robot is presented in [26]–[28]. Ferreira et al. in [29] and [30] presented a multidegree of freedom standing wave miniature piezoelectric robot. A traveling wave miniature piezoelectric robot for bi-directional motion was presented by Hariri et al. in [31]–[33]. Jones et al. in [34] presented a multidegree of freedom traveling wave miniature piezoelectric robot for an underwater propulsion. Koza et al. in [35] suggested a traveling wave Flagellar swimming using piezoelectric bimorph actuators. Abadi and Kosa in [36] presented a multidegree of freedom traveling wave miniature piezoelectric robot to control the location of the electrode in deep brain stimulation. A “flying” carpet near a horizontal surface based on piezoelectric traveling wave generation is presented by Jafferis and sturm in [37].
