Height comparison (via Harvard)
Soft robots (flexible) have several methods of locomotion that includes walking, crawling and rolling but now researchers from Harvard and Cornell University have added another method that involves small explosions. The researchers, led by assistant professor (from Cornell University) Robert Shepherd, designed a 3-legged soft robot that’s capable of leaping a foot into the air by capitalizing on a small-scale internal explosion. To design the robot the team used a 3D printer to fabricate the robot’s body, which is made from soft pliable silicon. This allows the form to contort in a variety of positions with relative ease over rigid plastics, which allows the robot to move in limited spaces at a quick pace. To get the robot to jump the team installed a series of tubes that deliver a precise amount of oxygen and hydrogen to hollow channels in each of the robots legs.
The soft robot igniting the reaction. Flames shoot down channels of the extremities. This enables the bot to just many times its height. (via Harvard demo video)
The gas mixture is “lit” using wires that generate an electrical current, which is regulated by a simple valve actuator. Heat generated by the ignited gas forces a flap (on each leg) to close which pressurizes the leg and causes it to actuate. Once the gas cools, the flap opens back up and more gas is piped in to expel the exhaust. While some may think that the explosions and heat would inherently damage the soft robot, the detonation is actually so short that the soft silicon is able to absorb the energy with relative ease. It can even handle the heat as the research team found that, over time, the resulting build-up of heat was less than 1 Kelvin after prolonged detonations. While the robot is limited in range due in part by being tethered by gas tubing and electrical wiring, they hope to develop their robot with a fully contained energy system, which would be a prerequisite for applications such as search and rescue operations sometime in the future. They would also have to figure out a way for the robot to travel in different directions either autonomously or by RC, otherwise it will be limited in most applications. First step’s first.
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