Img/2012/3/21/jellyi.jpgWashington: In a technological innovation, scientists in the US claim to have created a hydrogen-powered robot which can move through water just like a jellyfish.
A team at Virginia Tech University says that though the robot, nicknamed Robojelly, is in the early stages, it could eventually be used in underwater rescue operations, the `Smart
Materials and Structures` journal reported.
Due to its simple swimming action, jellyfish is an ideal model for a vehicle. And, being fuelled by hydrogen means, in theory, the robot will not run out of energy, the team says.
Yonas Tadesse, the lead author of the research, was quoted by the `BBC` online as saying, "To our knowledge, this is the first successful powering of an underwater robot using external hydrogen as a fuel source."
A jellyfish moves using circular muscles in the inside of its umbrella-like bell. As they contract, the bell closes in on itself and ejects water to propel itself forward. When the
muscles relax, the bell regains its original shape.
To replicate this, the vehicle uses shape memory alloys - materials that "remember" their original shape. These are wrapped in carbon nanotubes - tiny "straws" of pure carbon
that are renowned for their electrical properties - and coated with a platinum black powder.
The robot is powered by heat-producing chemical reactions between the oxygen and hydrogen in water and the platinum on its surface. The heat from the reactions is transferred to the artificial muscles of the robot, and reshapes them.
This means Robojelly can regenerate fuel from its surroundings rather than running off an external power source or batteries, say the scientists whose study was sponsored by
the US Office of Naval Research.
Currently, the jellyfish flexes its eight bell segments at the same time but there are plans to look at how to control each segment individually. This would mean the robot could be
closely controlled and move in different directions.
First Published: Wednesday, March 21, 2012, 14:28