MIT’s Thumb‑Sized Hopper: Small Robot, Big Leap

This little dynamo—smaller than a human thumb and lighter than a paperclip—combines a springy leg and four flapping wings to hop across tricky terrains with energy‑saving finesse. It can leap roughly four times its height (about 20 cm high), cruise at 30 cm/s, and tackle uneven ground, slippery surfaces, or even land on a drone—all while using about 60% less energy than a similarly sized flying robot. Plus, its hopping efficiency lets it haul payloads up to ten times heavier than itself, paving the way for real-world rescue missions or remote exploration with sensors, circuits, and batteries aboard.

“Being able to put batteries, circuits, and sensors on board has become much more feasible with a hopping robot than a flying one. Our hope is that one day this robot could go out of the lab and be useful in real-world scenarios,” says Yi-Hsuan (Nemo) Hsiao  , an MIT graduate student and co-lead author of a paper on the hopping robot.

Transcript

00:00:00 [MUSIC PLAYING] NARRATOR: Insect scale robots have size on their side, allowing them to squeeze into places that larger counterparts can't. However, tiny, crawling robots might encounter obstacles on the ground they cannot overcome, and while aerial robots can avoid these hazards, the amount of energy required for flight could limit how far they can travel before needing to recharge. Offering an alternative, a team of researchers at MIT

00:00:27 has developed a hopping robot that can leap over obstacles and jump across slanted or uneven surfaces, while using far less energy than an aerial robot of comparable size. This hopping robot, which is smaller than a human thumb and weighing less than a paperclip, has a springy leg that propels it off the ground and four flapping wings that give it lift and control its orientation. The robot can jump up to four times its height

00:00:54 and has no trouble hopping across ice, wet surfaces, and uneven soil. The key to the hopping robot's performance is a fast control mechanism that determines how the robot should be oriented for its next jump. Sensing is performed using an external motion tracking system, and an algorithm computes the necessary control information using sensor measurements. As the robot hops, it arcs in the air. At the peak of this arc, it estimates its landing point.

00:01:23 Based on this target landing point, the controller calculates the desired takeoff velocity for the next jump. Meanwhile, the robot flaps its wings to adjust its orientation, ensuring it strikes the ground at the correct angle and axis to move in the proper direction and at the right speed. The researchers tested the hopping robot and its control mechanism on a variety of surfaces. It successfully traversed all of them,

00:01:46 including a surface that was dynamically tilting. Since the controller can handle multiple terrains, the robot can easily transition from one surface to another, and due to its small size and light weight, the robot has an even smaller moment of inertia, which makes it more agile and better able to withstand collisions. Moving forward, the researchers plan to install batteries, sensors, and other circuits directly onto the robot in the hope of enabling it to hop

00:02:12 autonomously outside the lab.