Rib-bot! Scientists Use Frog Cells To Build Robots

What do robots and frogs have in common? Not a lot.

But the amphibians’ stem cells have proven pretty useful to US scientists who have managed to produce the world’s first living, self-healing robots using stem cells from our croaky friends.

Researchers in Vermont used the cells of African clawed frogs to successfully build the tiny robots, called Xenobots, that can perform particular tasks such as moving around or transporting a small load (like drugs or medicine) in a pouch, the University of Vermont said in its report.

Apparently the tiny robots can also heal themselves when damaged or cut which means they will never require the need for tricky maintenance and repair. To make matters even easier, once they’ve done their job, they can break down themselves as many natural living organisms do.

Stem cells work because they are a particular type of cell that have the ability to develop into many different cell types, from muscle cells to brain cells.

On the left, the anatomical blueprint for a computer-designed organism, discovered on a UVM supercomputer. On the right, the living organism, built entirely from frog skin (green) and heart muscle (red) cells. Image: Sam Kriegman, UVM

Michael Levin, director of the Allen Discovery Center at Tufts University in Massachusetts, said these are “entirely new lifeforms”.

“They have never before existed on Earth. They are living, programmable organisms.”

While scientists tend to stick to metal and plastics as their preferred materials for building robots, they are beginning to see the potential in making machines from biological tissues because they have a less harmful influence on the world – such as no contribution to plastic pollution.

These novel living machines are neither a traditional robot nor a known species of animal. They're a new class of artifact: a living, programmable organism, according to computer scientist and robot expert at the University of Vermont, Joshua Bongard.

The bizarre creatures were created using an "evolutionary algorithm" a supercomputer that generates 3D configurations of 500 to 1,000 skin and heart cells before being assembled and tested by biologists at Tufts University.

Every design is then trialed in a virtual environment to see how well they move and whether the heart cells are beating.

Researchers waited until the supercomputer had produced more than 100 versions before choosing a few of the best and allowing them to spawn.

Then, researchers scraped living stem cells from frog embryos and left them to incubate.

Afterward, the cells were cut and reshaped into specific "body forms" designed by the supercomputer.

"We can imagine many useful applications of these living robots that other machines can't do. Like searching out nasty compounds or radioactive contamination, gathering microplastic in the oceans, traveling in arteries to scrape out plaque,” Levin said.

Heart cells contract on their own allowing the robots to move spontaneously.

"These reconfigurable organisms were shown to be able to move in a coherent fashion -- and explore their watery environment for days or weeks, powered by embryonic energy stores. Turned over, however, they failed, like beetles flipped on their backs," the university report said.

A manufactured quadruped organism, 650-750 microns in diameter—a bit smaller than a pinhead. Image: Douglas Blackiston/Tufts University.

Xenobots could help researchers understand more about cell biology which could aid in the advancement of human health.

Levin concluded if society is going to move forward, we must better understand systems where "the outcome is very complex."

"A first step towards doing that is to explore: how do living systems decide what an overall behavior should be and how do we manipulate the pieces to get the behaviors we want?"