To date, manufacturing a robot usually involves a series of often-complicated steps, integrating a variety of high-tech components in precise configurations. But not anymore. At least not for a group of engineers at UCLA who have been creating robots in a single step. And “single step” isn’t hyperbolic; nearly all the elements needed for an operational robot, including its electronic and mechanical systems, are constructed all at once using a cutting-edge 3D printing process. The only post-printing addition is a small battery to provide power.

It’s made possible through a 3D printing technique that involves piezoelectric metamaterials, which are a distinct class of intricate lattice materials that can change shape and shift when acted on by an electric field, as well as create an electrical charge in response to physical force. The structural and piezoelectric elements of the mini-robots can expand, contract, rotate, twist, and bend with remarkable speed. UCLA researcher Huachen Cui says, “This allows actuating elements to be arranged precisely throughout the robot for fast, complex, and extended movements on various types of terrain.”

“It’s similar to a biological system with the nerves, bones, and tendons working in tandem to execute controlled motions,” says lead researcher and UCLA engineering professor Xiaoyu (Rayne) Zheng. According to a study released by the research team, these fingernail-sized “meta-bots” can “walk, maneuver, and jump,” and are capable of “sensing and decision-making.” So far, the team has printed three different tiny robots with different capabilities. One meta-bot has the ability to navigate around randomly placed obstacles and through an S-shaped maze. Another is something of an escape artist, able to get away when it detects contact with an object. The third can traverse rough terrain and make small jumps.

What real-world applications can these tiny meta-bots be used for? Professor Zheng says 3D printing could be used to create biomedical robots, such as self-steering robots with the ability to swim that could navigate through blood vessels to deliver targeted drug payloads and capture images with tiny endoscopes. Zheng also envisions the meta-bots exploring hazardous or otherwise inaccessible environments, such as a collapsed building in which people are trapped.

Is this the future of robot building? Zheng thinks so, saying, “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.”