The advent of 3D printing has changed many products and introduced many new ones, some of them good and some of them downright dangerous, like almost undetectable handguns. However, they have all been limited by size. A 3D printer cannot make anything bigger than itself. Enter the experience of wasps and bees.
Wasps and bees have the ability to build in flight. They build their nests and hives as they are flying. To assemble a hive or nest, worker insects team up to deposit wax, raw wood pulp, or their own saliva to the specification of a complex design that ends up being many times their size. The process takes can take months, which is many times the average lifespan of any individual insect, except the queen. They have to adjust the building as they go. Plans can change, imperfect building materials can degrade and individual workers die. However, eventually the nest or hive is successfully built. In a way, it is a bit like 3D printing, which builds objects incrementally in layers as well.
A roboticist at Imperial College, London, was inspired by this building technique to create a more flexible 3D printing system. He used the inspiration of wasps and bees to create a 3D printer nozzle that was equipped with wings – a drone.
The concept uses two types of drones: one is a scanner drone and the second is a builder drone. The scanner drone is equipped with cameras to monitor the building process and the builder drone is equipped with the 3D printing nozzle. The building process alternates the use of both drones.
First, the builder drone hovers over the area of operation, and begins to excrete from its nozzle the first layers of material. The scanner drone then flies in and inspects what has been built, returns that information to the computerized building software, which then calculates what the next layers should be. That information is then sent to the builder drone and the process is repeated over and over again.
The material used is obviously important since it must be light enough for the builder drone to carry. Low-density polyurethane foam works, as does a mixture made from cement. Also, since we are talking about building larger structures here, human intervention is possible to correct any errors that might occur. Initially, this will also mean possible modifications to the software on the fly, just like the bees and wasps.
One thing the researchers initially discovered is that a flying 3D nozzle is not accurate enough to build perfect concentric circles on top of one another as the “building” grows. So they programmed the 3D printing nozzle to make “squiggly” circles that interweave as they are built.
The experiment succeeded. They build a polyurethane cylinder 2 meters tall and a cement-mixture cylinder 18cms tall. Each finished structure was within 5mm of the original planning width and height. A percentage that is within the limits of British building codes.
Dr. Mirko Kovac, the head of this research project, said that because the drones can operate anywhere, at any location or height, they will initially be devoted to repairs, where human access is dangerous or impossible. Repairs on oil or gas pipelines, repair of leaky insulation, or fixing cracks on tall buildings are some of these possible uses.
Longer term, 3D printing drones could be deployed to construct buildings on the Moon or Mars. A drone has already been flown on Mars, so this is not such a far-fetched idea.
I must say it is good to report such innovative, progressive and positive ideas produced by human beings when it seems that everything around us is dominated by the destructive tendencies of our species.