3D-Printed Miniature Robots with Piezoelectric Actuation for Locomotion and Steering Maneuverability Applications

Abstract

The miniaturization of robots with locomotion abilities is a challenge of significant technological impact in many applications where large-scale robots have physical or cost restrictions. Access to hostile environments, improving microfabrication processes, or advanced instrumentation are examples of their potential use. Here, we propose a miniature 20 mm long sub-gram robot with piezoelectric actuation whose direction of motion can be controlled. A differential drive approach was implemented in an H-shaped 3D-printed motor platform featuring two plate resonators linked at their center, with built-in legs. The locomotion was driven by the generation of standing waves on each plate by means of piezoelectric patches excited with burst signals. The control of the motion trajectory of the robot, either translation or rotation, was attained by adjusting the parameters of the actuation signals such as the applied voltage, the number of applied cycles, or the driving frequency. The robot demonstrated locomotion in bidirectional straight paths as long as 65 mm at 2 mm/s speed with a voltage amplitude of only 10 V, and forward and backward precise steps as low as 1 µm. The spinning of the robot could be controlled with turns as low as 0.013 deg. and angular speeds as high as 3 deg./s under the same conditions. The proposed device was able to describe complex trajectories of more than 160 mm, while carrying 70 times its own weight.

Multidirectional Planar Motion Transmission on a Single‐Motor Actuated Robot via Microscopic Galumphing

“…Drawing on the galumphing and slipping motions, we propose a lightweight multimodal crawling robot. Within the realm of small‐scale planar crawlers, the key performance metrics include mass, speed, and power source, as depicted in Figure 5I 1‐8,10‐13,17,19,22‐44 . Soft‐crawling robots are predominantly externally powered and can weigh as little as 0.9 g. [ 19 ] Conversely, many rigid crawling robots utilize battery power and can weigh as little as 1.7 g. [ 2 ] The GASR possesses a light weight of 1.2 g and an average speed of 1.1 BL s −1 , nearly rivaling externally powered robots.…”

“…Within the realm of small‐scale planar crawlers, the key performance metrics include mass, speed, and power source, as depicted in Figure 5I . 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 10 , 11 , 12 , 13 , 17 , 19 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 Soft‐crawling robots are predominantly externally powered and can weigh as little as 0.9 g. [ 19 ] Conversely, many rigid crawling robots utilize battery power and can weigh as little as 1.7 g. [ 2 ] The GASR possesses a light weight of 1.2 g and an average speed of 1.1 BL s −1 , nearly rivaling externally powered robots. Furthermore, robots employing unstable galumphing and vibration‐based slipping are located within the red and blue regions of the performance space, respectively.…”

Developments and Challenges of Miniature Piezoelectric Robots: A Review

“…However, the CNC machining method is difficult to process some special microstructures, which cannot meet the further miniaturization and special design requirements of MPRs. Then, some new fabrication methods are applied to MPRs with miniature and special structure designs, mainly including additive manufacturing (AM) method [ 219 , 220 , 221 ] and smart composite microstructure (SCM) method, [ 222 , 223 , 224 ] as shown in Figure 11 a . The AM method, also referred to as 3D printing method, has the unique advantages for the cost‐effective fabrication of complicated 3D geometries with multiple materials at multiple scales.…”

Texturing to Dramatically Increase Thermal Deformation of Bilayer Film and Application to Actuator

“…These actuators require smaller, lighter, and larger deformations. Many types of actuators exist, e.g., piezoelectric actuators using the inverse piezoelectric effect [6,7], shape memory alloy actuators using the shape memory effect [8,9], and bimetallic actuators using the difference in thermal deformation [10]. In all these, it is difficult to obtain a large self‐generated deformation.…”