Meet the xenobots

When we think of a robot, what usually comes to mind is some kind of synthetic servant – a metal-clad machine controlled by electronics. While it might do chores for us and perhaps even talk to us in ways that seem intelligent, we wouldn’t regard it as alive.

But what if, instead of building robots out of hard, lifeless materials, we built them out of the soft materials that nature relies on? What if we built them out of cells?

This is exactly the approach that researchers in Prof Josh Bongard’s lab at the University of Vermont in the US are taking.

For the last four years, they have been designing and creating ‘xenobots’: miniature machines made from living frog cells. Bongard explains the team’s approach: “[If you] make a robot out of metal and plastic … the pieces themselves have no intelligence.

“We’re approaching robotics in a completely different way. We’re building from components that are themselves fantastically intelligent machines.”

Nature has been inspiring robotics for decades. It’s led to actuators based on real muscles that allow robots to move more easily. Elsewhere, pads that mimic geckos’ feet let robots climb vertical glass. Xenobots, by contrast, are made from nature’s own building blocks.

According to Dr Victoria Webster-Wood, an expert in biologically inspired robots at Carnegie Mellon University, this type of approach “enables us to directly harness living materials’ natural adaptability.”

What’s fascinating about Bongard’s xenobots is that they can be made from normal cells taken from frog embryos – no genetic tweaks required.

Although scientists already knew these cells could move on their own, in this case they’re being used as materials to generate predictable, robot-like behaviours, such as herding particles around a Petri dish, cooperating like sheepdogs and even birthing balls of other cells that might be regarded as xenobot babies.

Science Focus