Bendy bots use twisty telescopic limbs

Researchers at Carnegie Mellon University have formulated a new technique for designing telescopic structures that can bend and twist, forming collapsible robots.

Telescopic lizard

Traditionally, telescopic structures have taken on straight forms. Now, the Carnegie Mellon team has devised algorithms that transform complex shapes into curved telescopic forms, where smaller pieces nest within larger ones. The tool has been used to design a rapidly deployable tent structure, as well as telescopic robotic lizards and octopuses.

“Telescoping mechanisms are useful for designing deployable structures,” said Keenan Crane, assistant professor of computer science at Carnegie Mellon. “They can collapse down into really small volumes and, when you need them, are easily expanded.”

Though the nested pieces can potentially have a variety of shapes, the team focused on those with circular cross sections, similar to a sailor’s spyglass. Using this shape, the researchers found that it was possible for individual curved segments to rotate, adding 3D twists to what otherwise would be 2D shapes.By adding connectors, the team was able to combine several telescopic structures into larger assemblies.


Crane, working alongside assistant professor of robotics Stelian Coros and computer science PhD student Christopher Yu, developed a number of 3D printed prototypes. These included the tent-like shelter, a reconfigurable arm and several branching joints. On top of this, a range of other designs was explored using simulation, including organic shapes that resembled lizards and other animals.

Telescopic arm

According to the researchers, one promising application of the technology is for search and rescue robots. To demonstrate the potential, the team devised a robotic arm and claw that can emerge from a compact cylinder to reach up and over obstacles.

The researchers will present their findings at the SIGGRAPH Conference on Computer Graphics and Interactive Techniques in Los Angeles next week, and their project paper can be found here.