admin A half-millimetre crab shaped remote controlled robot built by engineers at Northwestern University can bend, twist, turn, crawl, walk and jump. This remote controlled robot is the smallest in the world and is controlled using lasers. And its USP is that it performs all these functions without any actuators, motors, hydraulics or electricity.
Built using a special alloy with shape-memory property that allows it to transform into a particular shape on the application of heat, the robot is first of its kind. The research was documented in an article titled, “Submillimeter-scale multi material terrestrial robots,” which was published in the Science Robotics journal.
John Rogers, who led the experiment, explained the working of the robot. He is the Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery at Northwestern University’s McCormick School of Engineering. He said that the joints start in a bent knee configuration. When heat is locally applied to the shape memory alloy at the joint, the knee will instantaneously shift to recover that planar geometry.
The tricky part is to make it go back to the deformed position. For this, they have used glass. They have covered the limb with a thin coating of glass as a layer. Upon cooling, the elastic resilience of that thin glass coating makes it bend back to that original bent shape.
A focused laser beam is being used by the researchers for applying localised heat to heat up different parts of the miniscule robot in a specific sequence. The special properties of the alloy and the tiny shape of the robot are the two main factors that allow each “limb” to cool down really fast once the heat source is moved away. The changing shapes of the different limbs as a result of this heating and cooling makes the robot move in a particular way. This depends on the sequence in which the laser is applied.
The researchers have also created robots using other creatures as their inspiration. The list includes inch worms and grasshoppers. The researchers hope to make these robots capable of carrying out various tasks.
Magazine 
