Laser cutters use lasers to cut shapes into existing material, but Rice University scientists have figured out how to make one build objects instead of cut them. The result is the $2,000 3D printer that you see above, constructing the blood vessel network inside a mouse liver.
If we want to maximize the usefulness of 3D printers, we have to maximize the number of materials they can work with, while minimizing the cost. That was the goal of the Rice scientists, when they devised a way to make a 3D printer with a couple of days, a couple of thousand dollars, and a laser cutter. Industrial-grade 3D printers of a similar design sell for hundreds of thousands if not millions of dollars. The scientists published their results in in PLOS One.
Unlike the increasingly popular consumer-grade 3D printers, which squirt out material through needles, this printer works a bit like a creme brulee torch—if a torch made structures on which people could grow human bone. The laser cutter is modified into a Selective Laser Sintering (SLS) printer. A layer of powder gets thrown down onto a surface. The laser is focused on the surface, just as it would be if it were making a cut. But instead of cutting through the powder, the heat from the laser causes the powder to melt and fuse together. Down goes another layer of powder, and the laser moves on, slowly making a complex structure. This SLS technique is used by companies like Shapeways to produce batches of products while preserving as much of the raw material as possible.
This printer works with nylon powder and polycaprolactone (PCL). The former material is widely available, while the latter holds a lot of potential as a biomaterial. It’s biodegradable in the body, so scientists have been looking at is as a potential implant.
These researchers used PCL more as a framework. Mesenchymal stem cells are cells that can potentially turn into bone, cartilage, and fat. “We demonstrated that human mesenchymal stem cells were able to adhere, survive, and differentiate… on sintered and smoothed PCL surfaces, suggesting that Open SLS has the potential to produce PCL scaffolds useful for cell studies,” the authors wrote in their PLOS One paper.
This means that researchers might be able to cheaply, and effectively, build a scaffolding for cells that will turn into a skeleton.