Assembling a robot is difficult. Creating one that can sense the environment and learn to move on its own is even more difficult.
But UCLA engineers took on an even bigger challenge. Not only did they create autonomous robots, they also 3D printed them in one step.
Each robot is the size of a fingertip. Their bodies resemble an N-shaped bamboo mat, and they glide at speeds of up to 25 feet per minute.
This feat is made possible by the invention of a new type of all-in-one material that is capable of bending, twisting, bending and stretching.
“The traditional robots you see today rely on a lot of different components,” he said. Rein Zheng, mechanical engineer and project manager. The body of the robot, its moving parts and its electronics must be built separately and then assembled together. “With 3D printed materials that can be robotized, we don’t need any of that.”
“Many times 3D printing has been used as a novelty to create hype… but that’s not the case here,” he said. Ryan SochoI am a robotics engineer at the University of Maryland who was not involved in the study.
Robert McCurdy, who designs automated robots at the University of Colorado Boulder, called UCLA’s work “a true innovation in 3D printing technology.” He said that the printing of mobile, shape-shifting material with embedded electronic components and remote sensing capabilities had not been achieved before, and this portends “robot manufacturing in the future.”
Zheng and his colleagues started the project three years ago to see if they could use 3D printing to create a material that could sense its environment — like measuring the temperature of an environment and noticing if it had been hit or crushed. .
Once they reached that goal, they added another one. “We started thinking, beyond the feel, why not make it move?” Zheng said.
And they still wanted to do it all in one step.
Conventional 3D printers work like a machine that adds icing to a cake. They create thin layers of plastic, metal, glass, or other materials to produce an endless list of products such as jewelry, tools, prosthetics, and more. even pizza. But they can only print one component at a time.
To print the entire robot at once, Zheng and his colleagues needed a versatile material. So they created one in silicon carbide that supports the structure of the robots; electrodes made of copper and gold, through which current flows; and piezoelectric ceramics, which change shape in response to an electric field.
Each part contributes to an entirely new “metamaterial” that can bend and bend, stretch and shrink, twist and turn, said Huachen Cui, a researcher in Zheng’s lab who led its development. And the metamaterial can be 3D printed in one go.
The new material required a dedicated 3D printer, so the team created a printer that takes the place of an office desk. Its principle of operation is similar to instantly freezing the design in a glass of water and draining the rest, leaving behind an intricate ice sculpture. But instead of water, the printer alternates containers of three ingredients, then uses ultraviolet light to solidify each layer of the metamaterial lattice as the robot takes shape.
The result is basically like a muscle. “It integrates everything from structural components, sensory components to motion and electronic control,” Zheng said.
In other words, according to McCurdy, it’s truly a functional object: “When it comes out of the 3D printer, it doesn’t require any additional assembly.”
Cui tested the robot by placing it on a table between a pair of pipes. A set of wires tied the robot to a power source. When powered on, the robot came to life with an uncharacteristic bright green flash, accompanied by wisps of smoke. But soon he stirred with the soft buzz of an electric razor.
The three parts of its N-shaped body form a muscle that flexes faster than the eye can see, pushing it forward with ease. It can even jump over tiny obstacles about 1 millimeter high.
The design was inspired by nature.
“I wanted to make it agile and very fast — the first thing that came to my mind was a leopard,” said Cui, lead author of the study. “You just have to hit the ground and move forward. That’s all. “
Robots rely on ultrasound to sense their surroundings, much like bats. But instead of using echolocation, the machines use a 3D-printed remote sensor that reflects radar pulses in different directions. The way they bounce alerts the robot to obstacles in its path so it can adjust accordingly.
Cars that are small enough to fit on a penny can carry 13 times their own weight. When Cui threw the bolt into the basket attached to the top of the robot, he flinched and began to move faster. The strike, designed to mimic falling debris, was the signal for a quick escape, he said.
Zheng said it wouldn’t be hard to make the robots bigger – all they need is a larger 3D printer. The real challenge is to make robots smaller and more capable of working in water.
This is what excites Sohol.
“I think biomedical applications, especially drug delivery, is an application where this can really have legitimate applications,” he said. He presented a scenario in which a tiny robot delivers a dose of a drug to a specific location in a blood vessel. Once it’s in position, doctors can “hit it with an electric field” to force it to release its payload.
Zheng’s laboratory is already equipped with a small tank on the floor for testing future generations of aquatic robots. If the leopard inspired the original version, then the new models will mimic the swimming and crawling ability of the shrimp.