When engineers from Harvard made a robot, they wanted to bring together the speed and autonomy of a rigid robot and the resiliency and adaptability of a soft one, and make producing the resulting robot quick and cheap. Thanks to 3-D printing, they were able to do just that.

In the journal Science, Harvard engineers detailed a design (built from previous work by George Whitesides, one of the authors for the research) offering a fresh solution to the challenge plaguing soft robotics: integrating soft and rigid materials. Powered by combustion, the robot is made up of two main components: a shielded rigid core fitted with control and power components and a soft body equipped with three pneumatic legs.

To move, the robot's pneumatic legs are inflated, allowing it to tilt its body in whichever direction it wishes to go. Oxygen and buten are then combined and ignited, propelling the robot up. The force is so powerful that the robot is able to jump vertically six times its height. If its jumps to its sides, it covers distances half the length of its body. The robot's jumping ability is favored in the field because it could be effective in getting the robot away easily and quickly around obstacles.

"The robot's stiffness gradient allows it to withstand the impact of dozens of landings and to survive the combustion event required for jumping," said Nicholas Bartlett, co-first author for the research. He also highlighted that the robot's design allows it to move much more quickly compared to the usual soft robot.

According to Robert Wood, senior author for the research, soft robotics is relatively new as a subfield. However, 3-D printing is greatly contributing to the number of things that scientists in the field can do practically.

3-D printing helps make inventions more cost-effective because it does away with customized molds as well as multi-step assembly processes which are slow. As more materials become compatible for use in 3-D printing, the easier it is for scientists to create prototypes and further their research.

The research received support from the Wyss Institute and the National Science Foundation. To pursue opportunities to commercialize, Harvard's Office of Technology Development has also field for a provisional patent on the work.

Other contributors to the research include: Michael Tolley (University of California, San Diego); Bobak Mosadegh (Weill Cornell Medical College); James Weaver (Wyss Institute); Katia Bertoldi (SEAS); and Johannes Overvelde (SEAS).