In this paper, we developed a kinematic model for a legged piezoelectric miniature robot driven by standing wave. The robot consists of a piezoelectric bending actuator with rigidly attached legs. The kinematic model allows us to compute the velocity analytically so that the robot motion can be predicted. To construct the kinematic model, the behavior of the robot at the contact instances with the ground during the up and down stages is studied. A prototype is fabricated so as to verify our kinematic model experimentally, measured using a motion capture system. The result shows that the measured speed was in close agreement with what was predicted by our model.

In this paper, the operation principles of a traveling wave piezoelectric beam robot are presented. A prototype consisting of an aluminum beam structure, with two non-collocated piezoelectric patches bonded on its surface, was fabricated and tested to demonstrate the generation of a traveling wave on the beam based on the one mode excitation and the two mode excitation operation principles for propulsion. A numerical model was developed and used to study and optimize the generated motion of the piezoelectric beam robot. Experimental characterization of the robot for the two types of operation has been carried out, a comparison between them is made and results are given in this paper.

In this paper, a concept design of a novel Traveling Wave Driven Piezoelectric Plate Robot (TWDPPR) for planar motion is presented. The TWDPPR consists of an aluminium plate structure, with four non-collocated piezoelectric patches bonded on its surface. A two dimensions modeling of non-collocated piezoelectric patches bonded on thin structures developed and validated in previous work is used in this paper to model the TWDPPR based on the “two modes excitation” method for propulsion. A preliminary design is presented and the model is then used to verify the generation of the 2D traveling wave on the plate for planar motion. A prototype is fabricated and a forward, backward, & steering motions are experimentally achieved. An experimental characterization of the TWDPPR is given in this paper.

Inspired from linear traveling wave ultrasonic motors, a dual piezoelectric beam robot is presented. It consists of an aluminum beam structure, with two non-collocated piezoelectric patches bonded on its surface. The aim of this article is to study the effect of the piezoelectric patches’ positions on the performance of the robot. For a given robot dimension, a finite element model developed in a previous work for the robot structure is verified experimentally here and then used to determine the optimal piezoelectric patches’ position. It has been found that locating the piezoelectric patches near the ends of the beam will lead to best performance, and that the traveling wave is mainly generated between the two patches. Two prototypes have been manufactured for this aim and have shown good agreement with simulation results.

This paper describes the design and evaluation of a Legged Piezoelectric Miniature Robot (LPMR) propelled by standing wave vibrations at the legs, which are biologically inspired by the bounding gait locomotion of animals. The LPMR comprises of a single piezoelectric patch, a metal beam, two contact joints, two rigid legs and is able to achieve tether-less remote controlled operation. Through analysis of the bending modes of vibrations and driving frequency, a forward and backward motion of the underactuated system is achieved by choosing specific positions for the legs. At 100 V amplitude, the LPMR with the weight of 6.27 g, length of 50 mm, width of 10 mm and height of 1.5 mm achieves a maximum linear speed of 246.5 mm/s for forward motion and 302 mm/s for backward motion. The LPMR is also able to carry a payload of 100 g at a speed of 49.6 mm/s for forward motion and 87.9 mm/s for backward motion when applying 100 V amplitude. The corresponding maximum force generated by the LPMR is 9.8 mN during forward motion and 12 mN during backward motion at the same applied voltage. An experimental characterization for the LPMR in terms of speed versus applied voltage, speed versus embedded mass and blocking force for different applied voltages is explored and evaluated in this study.

This paper presents the design and development of a new type of piezoelectric-driven robot, which consists of a piezoelectric unimorph actuator integrated as part of the structure of a four-bar linkage to generate locomotion. The unimorph actuator replaces the input link of the four-bar linkage, and motion is generated at the coupler link due to the actuator deflection. A dimensional synthesis approach is proposed for the design of four-bar linkage that amplifies the small displacement of the piezoelectric actuator at the coupler link. The robot consists of two such piezo-driven four-bar linkages, and its gait cycle is described. The robot's speed is derived through kinematic modeling and experimentally verified using a fabricated prototype. The robot prototype's performance in terms of its payload capability and nominal operating power is also characterized experimentally. These results will be important for developing a motion planning control strategy for a autonomous robot locomotion, which will be part of future work.