3D-Printed MARS Rovers Harness Living Marimo to Autonomously Explore Freshwater Lake Beds
Taking advantage of gas generated during photosynthesis, these bio-robots can propel themselves along — and even float over obstacles.
A team of researchers from the wonderfully-named Unconventional Computing Lab of the University of the West of England (UWE) Bristol have shown off robots with a difference: They're powered by ball-shaped Marimo algae, formed by rolling currents in freshwater lakes.
Dubbed Marimo Activated Rover System, or MARS, the 3D-printed biologically-driven round robots, brought to our attention by Fast Company, mimic the spherical shapes of the algal agglomerations inside. It's this living green ball, which provides the robots' movement — and obstacle-avoidance capabilities.
The project builds on a paper published published in 2019, in which first author Neil Phillips and colleagues demonstrated how Marimo could be used to drive actuators, biosensors, and even "bioprocessors" equivalent to electronic oscillators and logic gates. "Photosynthesis therein produces gas bubbles that can attach to the Marimo, consequently changing its buoyancy," the team explained at the time. "This property allows them to float in the presence of light and sink in its absence."
The MARS robots use this self-same biological process: As gas bubbles form, they float towards the top of the spherical enclosure — and are trapped in specially-designed cells. When there's enough gas trapped, it causes the MARS rover to roll forwards — and if it hits an obstacle, the gas builds up until it's capable of floating right over the top.
It's possible that MARS rovers could be fitted with a range of sensors, and by using a long-lived biological organism for its driving force could run for over a hundred years entirely autonomously — though an alternative organism would need to be found to make MARS equivalents suitable for use in saltwater seas.
"The logistics of using MARS to survey a range of environments is being explored and will be reported in due course," the researchers promise. "MARS can utilize the continual green energy production of Marimo, and combine it with the system requirements of a particular mission (sensor load-out, buoyancy, etc.)"
The team's work has been published in the Journal of Biological Engineering under open-access terms.