RALEIGH, N.C. — Researchers at North Carolina State University have built a small, teardrop-shaped soft robot that can jump, land, reset itself, and jump again — continuously, without a battery, a motor, or any of the internal mechanisms that usually make a robot “a robot” in the way people imagine one. All it requires is infrared light, and someone willing to keep pointing it.

The device works by absorbing infrared light, which causes it to twist and launch itself into the air. During flight, the twist naturally unwinds and the robot returns to its original shape, effectively resetting itself before it lands. Then the same light-driven process begins again. As long as the light is on, the robot keeps jumping. Turn the light off, and it sits there, completely still, looking like a very disappointed water droplet.

"It does not need a battery, it does not need a motor, and it does not need to be reset by hand. It needs light. We have been pointing at things with lights for centuries. Now the thing we point at points back."

The team noted that small design changes to the shape of the robot allow it to leap upward, leap forward, or simply crawl along the ground, depending on the configuration — a versatility that, in the paper, is described as “significant” and, in the lab, is described as “it goes where we tell it to go, as long as the light is on.”

The practical applications are, at present, a matter of healthy speculation. The researchers point to potential uses in search-and-rescue, in environments where batteries are a liability, and in situations where a small, self-resetting object that simply keeps moving in one direction is, frankly, exactly what the job calls for. “The point is not that it is a robot,” one of the team’s members noted. “The point is that it is a robot that has no idea it is a robot, and that turns out to be useful.”

THE SELF-RESETTING JUMPER: SPECS

  • Power source: Infrared light. No battery, no motor, no reset button.
  • Reset mechanism: It untwists mid-air. On its own. Every time.
  • Range of motion: Upward, forward, or crawling, depending on the shape.
  • Range of motion when the light is off: Zero. It is a teardrop.

At press time, the team was working on a version that could, theoretically, jump across a room without anyone moving the light, a goal described in the paper as “the next step” and, in the lab, as “we are still pointing it, and we are still pointing it.”