Building conventional robots typically requires combining components like motors, batteries, actuators, body segments, legs, and wheels. A new approach builds a robot entirely from smaller robots called smarticles. The 3D-printed smarticles (smart active particles) can only flap their two arms. But when five of them are confined in a circle, they begin to nudge one another, forming a robophysical system known as a supersmarticle that can move by itself. Adding a light or sound sensor allows the supersmarticle to move in response to the stimulus — and even be controlled well enough to navigate a maze.
The approach of making robots from smaller robots — and taking advantage of the group capabilities that arise by combining individuals — could provide mechanically based control over very small robots. The emergent behavior of the group could provide a new locomotion and control approach for small robots that could potentially change shapes.
A 3D printer was used to create battery-powered smarticles, which have motors, simple sensors, and limited computing power. The devices can change their location only when they interact with other devices while enclosed by a ring. Although no individual robot can move on its own, the cloud composed of multiple robots could move as it pushes itself apart and shrink as it pulls itself together.
Researchers found that if one small robot stopped moving, perhaps because its battery died, the group of smarticles would begin moving in the direction of that stalled robot. The movement could be controlled by adding photo sensors to the robots that halt the arm flapping when a strong beam of light hits one of them.
The researchers are working on more complex interactions that utilize the simple sensing and movement capabilities of the smarticles. The project could lead to new robotic systems capable of changing their shapes, modalities, and functions; for example, a robotic swarm could move to a river and autonomously form a structure to span the gap.