Self-destructing bio-drones could be the next Mars explorers

A group of students from Brown, Spelman and Stanford University are collaborating with researchers from Nasa's Ames Research Centre on a biological drone, which they hope one day to send to Mars. 

Spearheading a project with a biodegradable drone that "self-destructs" and "dissolves" upon impact, the team is intent on upholding both the civic and scientific potentials of this versatile UAV -- so stealthy military implications are out of the picture. 

Project leader and astrobiologist, Lynn Rothschild told WIRED.co.uk that she had the idea of inventing a biodegradable drone when she noticed that the UAVs used by her scientific colleagues got lost-in-action. "Sometimes the UAVs sent out to observe coral reefs are lost and littering is a problem. You don't want to be responsible for littering the very ecosystem you're trying to protect. What if you lose the UAV in the ocean and it could just dissolve away," she asks. 

HOW "CODON SECURITY" MAINTAINS CONTROL

Eli Bloc

To construct the bio-drone, the team collaborated with material science company Ecovative, who specialise in the production of non-wasteful technology. The biodegradability of the drone stems from its fungal mycelium composition. But if you're wondering about the apocalyptic risk of this versatile drone spreading infections or altering the balance of the ecosystem upon dissolving, according to the team, there's no need to worry. "It's the same level of concern as dropping a sheet of paper outside," asserts Rothschild. 

So how did the team ensure that the drone did not transfer its genes into the environment? They worked on a concept called "Codon Security" -- a process, which mitigates the effects of horizontal gene transfer. In other words, by changing the genetic code of the engineered cells used in their bio-drone, the team ensured that upon contact with the environment the bio-drone's cells would have no effect on it.

"As we isolated and incorporated genes from extremophiles (organisms that live at extreme conditions) into our cells to make them resistant to high temperatures and radiation, it's important to prevent these 'super abilities' from transferring to normal cells [in the environment]," explains Stanford student Aryo Sorayya. 

"Codon Security allows us to maintain control, as opposed to creating one super bacterium and then always worrying about how that might affect other cells in the environment. We don't want to end up with a large number of cells in nature resistant to various conditions that they normally wouldn't be resistant to." 

For the moment, the team have integrated a timing mechanism within the bio-drone's chassis that triggers its "self-destruct" mode. "We're working on UAVs that work for 24 hours. At the onset of darkness, one cell starts degrading and tells the other cells to do the same," explains Sorayya. "The basic idea is that enzymes within the cells will turn everything into glucose until you end up with a puddle of sugar." 

THE FUTURE OF BIO-DRONES 

The brains behind the bio-drone are pretty ethically and scientifically clued up about the social perception and multiple usages of drones. And in order to get their project off the ground, they interviewed both environmental andNasa scientists interested in UAVs, and conducted social surveys to suss out what the public thought. "We wanted to overcome the stigmas associated with UAVs -- they have so many uses outside of the military," notes Sorayya. 

Biological drone made by iGEM 2014 students

The team have high hopes for their bio-drone, and the students behind the project are already working on the idea of incorporating visual sensors onto the chassis of their drone that would change colour upon detecting different gases in the atmosphere. 

"The idea is for the cells to change colour upon recognition of some toxic gas and transfer that data back somehow," explains Sorayya.

What's most important for the team is how these ephemeral bio-drones could benefit society at large. "Let's say you have a nuclear meltdown and there's a lot of radioactive activity, so you don't want to send someone into a zone. Imagine if the biodegradable drone could go in and send data back without anyone else having to come into contact with it," says Sorayya. 

So far, this bio-drone is still not completely biological as although the inner circuit is made from silver nanoparticle ink, the team has had to use non-biodegradable propellers and batteries. However, with student scientist designer, Eli Block, already working on speculative designs of what a future biological drone might look like, who knows what lies in store. 

MAPPING MARS WITH BIODRONES

Synthetic biology is a rapidly advancing field, and the team have ambitious plans for sending these bio-drones out on future orbital mapping missions in space.

"NASA is interested in taking things to space, but the more mass you take, the more expensive it is. If you could assemble things from cells up in space, it would be cheaper," says Sorayya. 

"We're working on taking small vials of cells up to Mars. The idea is for these cells to grow off the environment on Mars," says Rothschild. "In some ways, there biodegradation is not as important as their bio-production. Imagine if you could produce these drones so that they could map the surface of Mars."

With the growing buzz around e-commerce drones, and medical delivery drones set to proliferate, iGEM's bio-drone shows there's plenty of scope for civic-friendly UAV projects to have lift off into 2015.