Vibrations Drive Tiny Robots

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-11-26 11:39

Micro-robots developed by researchers at the Georgia Institute of Technology are about as small as the smallest ant in the world. The robot is so tiny that there is no space for an energy supply like batteries. That is why vibrations serve as an energy source - they can move even with the sound waves from a loudspeaker.

Tiny robot from the 3D printer

The micro-robots consist of a plastic plate to which the researchers glued a piezoelectric actuator. This converts vibrations into electrical energy that drives the robot forward. The prototype reacts to different frequencies so that it can be controlled to a certain extent. "We are working on making the technology robust," says assistant professor of electrical engineering and computer science, Azadeh Ansari. "And we have a lot of ideas for possible uses."

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The micro-bots are about two millimeters long, 1.8 millimeters wide and 0.8 millimeters thick and weigh about five milligrams. 3D printing could make even smaller robots, but with a reduced mass, the adhesive forces between the tiny devices and a surface can become very large. The problem can arise that the micro-bots are not separated from the tweezers with which they were picked up.

Moving with a tiny acoustic speaker

The vibrations by which the micro-robots move can come from a piezoelectric shaker beneath the surface on which the robots are moving, from an ultrasound / sonar source, or even from a tiny acoustic speaker. The vibrations move the springy legs up and down and thus drive the micro-robot forward. Each robot can be designed to react to different vibration frequencies, depending on the leg size, diameter, design and overall geometry.

The amplitude of the vibrations controls the speed at which the microbots move. And although the micro-robot is so tiny, it can travel four times its body length as a path within a second. Some of the robots have four legs while others have six. The lead author DeaGyu Kim made hundreds of the tiny structures to determine the ideal configuration.

Make micro-robots controllable

The robots are manufactured in a 3D printer using the TPP process, a technique that polymerizes a monomer resin material. Once the part of the resin block struck by the ultraviolet light is chemically developed, the rest can be washed away so that the desired robot structure is retained.

Ansari explains: "The manufacturing process is still quite a while away, so we're looking for ways to scale it to produce hundreds or thousands of microbots at the same time." Ansari and her team are working to control the robots by: connect two slightly different microbots. Since each of the connected bots would respond to different vibrational frequencies, the combination could be controlled by varying the frequencies and amplitudes.

robotics

When the robot parks the car

For the future, the researchers are considering developing microbots that can jump and swim. Ansari explains what else they are going to do: “For example, we can look at the collective behavior of ants and transfer what we learn from them to our little robots. The robots are doing well in a laboratory environment, but we still have a lot to do before they can go outside.”

A paper describing the micro-robots was accepted for publication in the "Journal of Micromechanics and Microengineering".

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