NASA hopes to cut costs by growing biological drones for Mars exploration.
NASA has been working on the prototype of a drone that they hope will one day survey Mars from low altitudes. Unlike past missions where we have sent the vehicles there, they are hoping to just send vials of cells in order to grow a biodegradable drone. In the summer of 2014, a team of students from Standford University, Brown University and Spelman College created a drone that would fit this bill, which was entered in the International Genetically Engineered Machine competition.
Lynn Rothschild is a synthetic biologist at NASA Ames Research Center in California; working with the team, they made a drone using biological material from plants and fungi. “These are lightweight, cheap, and won’t litter the environment,” says Rothschild. By the time the drone lifts off, the material is dead, allowing it to crash without worry of growing new colonies of fungus. How is a ‘bio-UAV’ built?
The iGEM team first designed the shape of the drone with 3D modeling software and sent it to a bio-materials company, Ecovative Design
. The company fabricated the drone body using fungal mycelium. They filled the mold with straw and dead leaves. “The biomaterial gets inoculated with fungus, then fungus grows throughout all the material in the mold,” explains Eli Block of the iGEM team. “Before where it was kind of a loose material, after growing for a few weeks, it was a single solid chunk.” At about 8 inches across and with a skin of bacterial cellulose acetate, two molds made up the chassis for the drone. “So it looks like a dried sandwich, and it’s the weight and feel of Styrofoam,” Rothschild says.
The drone then is sterilized. “The point of it is you’re not flying anything that could introduce negative organisms into the environment,” Block says. “Also you have this new biomaterial that you don’t want to get eaten by mold. So you don’t want it to break down immediately.
Several tests and experiments were conducted by the team, trying to find ways to make the biodegradable UAV able to fly in very harsh environments. A Stanford-Brown iGEM project in 2012 called “Hell Cells,
” are genetically-modified bacteria using genes of ‘extremophiles’ inserted into E. coli.
These Hell Cells are resistant to radiation and extreme hot and cold temperatures. These cells not only fortify the drone but could be used as biosensors to allow reading the environment. This would let a drone keep a real light weight by not needing expensive and heavy sensor equipment.