3D-Printed Robots Feature Shock-Absorbing Skins

Tech Briefs INSIDER

A “programmable viscoelastic material” (PVM) from the Massachusetts Institute of Technology (MIT) allows users to program every single part of a 3D-printed object, including exact levels of stiffness and elasticity.

The soft materials will make robots more precise in their movements and possibly improve the durability of drones, phones, shoes, and helmets.

After 3D-printing a cube robot that moves by bouncing, the MIT researchers outfitted the system with shock-absorbing skins that use only 1/250 the amount of energy being transferred to the ground.

“That reduction makes all the difference for preventing a rotor from breaking off of a drone or a sensor from cracking when it hits the floor,” says CSAIL Director Daniela Rus, who oversaw the project and co-wrote a related paper. “These materials allow us to 3D-print robots with visco-elastic properties that can be inputted by the user at print-time as part of the fabrication process."

The skins also allow the robot to land nearly four times more precisely, suggesting that similar shock absorbers could extend the lifespan of delivery drones like the ones being developed by Amazon and Google.

Employing a standard 3D printer, the team used a solid, a liquid, and a flexible rubber-like material called TangoBlack+ to print both the cube and its skins. The PVM process takes a page from Rus’ previous 3D-printed robotics work, with an inkjet depositing droplets of material layer-by-layer and then using UV light to solidify the non-liquids.

MIT's cube robot includes a rigid body, two motors, a microcontroller, battery, and inertial measurement unit sensors. Four layers of looped metal strip serve as the springs that propel the cube.