Functionally Graded Soft Robot

Traditionally, robots are rigid, resulting in fast, precise, and powerful movement. In contrary, soft robots are adaptable and resilient, although often slow, difficult to fabricate, and challenging to make untethered or autonomous because of weight and rigidity of the motors, pumps, batteries, sensors, and microcontrollers. In this work, we combined the best of both worlds by using 3-D printing techniques to fabricate a jumping soft robot from both rigid and soft materials.

The combustion-powered robot — reminiscent of a toy rubber popper — is constructed of two main parts: a soft plungerlike body with three pneumatic legs and the rigid core module, containing power and control components and protected by a semisoft shield created with a 3-D printer. To initiate movement, the robot inflates its pneumatic legs to tilt its body in the direction it wants to go. Then butane and oxygen are mixed and ignited, catapulting the robot into the air. It’s a powerful jumper, reaching up to six times its body height in vertical leaps and half its body width in lateral jumps. The robot’s jumping ability and soft body would come in handy in harsh and unpredictable environments or disaster situations, allowing it to survive large falls and other unexpected developments.


Bartlett, N. W., Tolley, M. T., Overvelde, J. T. B., Weaver, J., Mosadegh, B., Bertoldi, K., Whitesides, G. M., Wood, R. J., (2015) A 3D Printed, Functionally Graded Soft Robot Powered by Combustion. Science, 349, 161-165. [The Washington Post] [Discovery] [Harvard News] [pdf]