Ever since the 1966 film 'Fantastic Voyage', an American science-fiction about a submarine crew who are shrunk to microscopic size and venture into the body of an injured scientist to repair damage to his brain, it remained a possible concept for robotic engineers too. Many films followed the theme but here is a new research outcome that made it possible though at microbes level.

The team from the University of Vermont has succeeded by repurposing living cells of frog embryos into entirely new millimeter-long life-forms, called "xenobots", which can move toward a target, carry a payload which could be medicine and reach a specific body part of a patient to deliver it.

Novel living machines

"These are novel living machines," says Joshua Bongard, a computer scientist and robotics expert at the University of Vermont, who pioneered the research study successfully. "They're neither a traditional robot nor a known species of animal. It's a new class of artifact: a living, programmable organism."

Bongard says they tried to slice the robot almost in half and found it stitching itself back up and moving ahead. This is "something you can't do with typical machines. These xenobots are fully biodegradable. When they're done with their job after seven days, they're just dead skin cells," explained Bongard.

Initially designed on a supercomputer and then assembled and tested by biologists at Tufts University, these robots can have many useful applications as living robots that other machines cannot do, said Michael Levin, team member and director of Center for Regenerative and Developmental Biology at Tufts.

Applications in future

Some of the applications include searching out nasty compounds or radioactive contamination, gathering microplastic in the oceans, traveling in arteries to scrape out plaque. The results of the new research were published January 13 in the Proceedings of the National Academy of Sciences.

The team used an evolutionary algorithm to design the new life-forms, which can carry out tasks like locomotion in one direction. First they gathered stem cells, harvested from the embryos of African frogs, the species Xenopus laevis, which led to its name "xenobots."

Spontaneous motion

Assembled into body forms never seen in nature, the cells formed a more passive architecture, while the once-random contractions of heart muscle cells were put to work creating ordered forward motion and aided by spontaneous self-organizing patterns -- allowing the robots to move on their own.

Later, tests showed that groups of xenobots would move around in circles, pushing pellets into a central location -- spontaneously and collectively. "It's a step toward using computer-designed organisms for intelligent drug delivery," says Bongard.