Scientists develop new 3D printing technique to build self-driving robots in ‘one single step’

Engineers have developed a new 3D printing technique to build small autonomous robots in a single step, an advance that could lead to innovative “meta-bots” for drug delivery and rescue missions.

Researchers, including those from the University of California Los Angeles (UCLA), applied the 3D printing method to build and demonstrate an assortment of tiny robots that walk, manoeuvre, and jump.

Robots, irrespective of their size, are typically built in a series of complex manufacturing steps that integrate their limbs, electronic and active components.

In comparison, the new technique, described last month in the journal Science Advances, enables the entire mechanical and electronic systems needed to operate a robot to be manufactured all at once, scientists say.

The all-in-one method, according to researchers, is made possible by advancements in the design and printing of piezoelectric metamaterials – a class of intricate materials that can change shape and move in response to an electric field or create electrical charge as a result of physical forces.

The 3D printed materials consist of an internal array of sensory, moving, and structural elements that can move by themselves following programmed commands, scientists explain.

While typically these materials have limits in their range of motion and distance of travel, scientists say the new robotic materials – each the size of a penny – are composed of intricate structural elements that can “bend, flex, twist, rotate, expand or contract at high speeds”.

Once a “meta-bot” is 3D printed and assembled this way, they say it will be capable of propulsion, movement, sensing, and decision-making.

“We envision that this design and printing methodology of smart robotic materials will help realize a class of autonomous materials that could replace the current complex assembly process for making a robot,” study co-author Xiaoyu (Rayne) Zheng said in a statement.

“With complex motions, multiple modes of sensing and programmable decision-making abilities all tightly integrated, it’s similar to a biological system with the nerves, bones and tendons working in tandem to execute controlled motions,” Dr Zheng said.

In the study, researchers showed the integration with an on-board battery and controller for the fully autonomous operation of the 3D printed robots, each of which was the size of a fingernail.

Scientists believe the manufacturing technique could lead to new designs for biomedical robots, such as self-steering endoscopes or tiny swimming robots that can emit ultrasounds and navigate themselves near blood vessels to deliver drug doses at specific target sites inside the body.

They demonstrated three “meta-bots”, designed with the new technique, with different capabilities.

One robot could navigate around S-shaped corners and randomly placed obstacles, another could escape in response to a contact impact, and the third could walk over rough terrain and make small jumps.

Researchers say the advance could lead to the development of more novel tiny mobile robots that can actively sense and traverse different types of terrains.