NASA is working on a prototype drone that will be able to survey Mars from a modest altitude. But what if instead of shipping a drone to Mars, we could just ship small vials of cells, and use them to grow a biodegradable drone on the Red Planet? A team of students from Stanford University, Spelman College, and Brown University created such a drone last summer, which they then entered into the 2014 International Genetically Engineered Machine competition.
Working with Lynn Rothschild, a synthetic biologist at the NASA Ames Research Center in California, the team created a drone composed of biological material from fungi and plants. The material is dead by the time the drone goes airborne, so it won’t form a new fungal colony should it crash. “These are lightweight, cheap, and won’t litter the environment,” says Rothschild. “It’s about as big a concern as leaving your sweater outside.” So how does one make a “bio-UAV”?
To start, the iGEM team designed the drone’s shape in 3D modeling software. This design file was sent to biomaterials company Ecovative Design, which fabricated the drone body from an 8-inch square of fungal mycelium via vacuforming. Then Ecovative filled this mold with biomaterial: straw and dead leaves. “The biomaterial gets inoculated with fungus, then fungus grows throughout all the material in the mold,” explains Eli Block, a member of the iGEM team and a junior in a dual-degree program at Brown University and the Rhode Island School of Design. “Before where it was kind of a loose material, after growing for a few weeks, it was a single solid chunk.” Two of these molds, each about 8 inches across and skinned in bacterial cellulose acetate, formed the drone chassis. “So it looks like a dried sandwich, and it’s the weight and feel of Styrofoam,” Rothschild says.
“It looks like a dried sandwich, and it’s the weight and feel of Styrofoam.”
Next, the drone 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.”
