By Holly Rogers
A robotic jellyfish made of smart materials could be used in search and rescue operations, say researchers from Virginia Tech.
The tentacled creation, known as Robojelly, is made from a collection of materials that change shape or size to match their environment, held in place with carbon nanotubes. As well as its intelligent build, it could theoretically run forever – the clever cnidaria is powered entirely by hydrogen.
“To our knowledge, this is the first successful powering of an underwater robot using external hydrogen as a fuel source”, said Yonas Tadesse, the lead author of the study.
Robojelly is made from “shape memory alloys”, which are smart materials that remember their original shape. These materials are wrapped in carbon nanotubes and coated in platinum powder, which is the key to the fuel source. The platinum powder reacts with oxygen and hydrogen from the surround water and produces heat, which powers the robot’s movements.
Its swimming technique mimics that of a jellyfish – the “bell” chamber fills with water, which then collapses, forcing the water out and driving the body forwards. In jellyfish, this is done with muscle contractions, but Robojelly makes use of heat produced by the fuel cell to transform its smart material body. However, although Robojelly has been successfully tested in a water tank, it’s not quite ready for service yet. Developers need to add individual controls to each segment of the robot, which will allow it to be steered in different directions. Until then, it can be seen in testing phase below:
Y. Tadesse, A. Villanueva, C. Haines, D. Novitski, R. Baughman and S. Priya, Hydrogen-fuel-powered bell segments of biomimetic jellyfish, Smart Materials and Structures, 21, 2012.
The paper can be found at: http://iopscience.iop.org/0964-1726/21/4/045013