Bioengineers from Rice University have hacked a commercial-grade laser cutter to design and produce the new open-source sintering platform OpenSLS, which costs at least 40 times less than currently available commercial models.
OpenSLS is an open-source device that allows researchers to work with their own specialized powdered materials through sintering, a process where powders are placed under heat and pressure to produce a solid mass.
The ability to work with their own powders is something not commonly provided for by commercial SLS platforms, which cost upwards of $400,000. It is also an ability that is rather important in bioresearch and regenerative medicine, as researchers often wish to experiment with non-mandated materials.
OpenSLS, on the other hand, provides this functionality and can be assembled from low-cost, open-source microcontrollers for less than $10,000. It is even possible to utilize the machine's laser-cutting features to produce many of the acrylic parts for the powder-handling system, further reducing the cost.
"You can actually cut most of the required parts with the same laser cutter you are in the process of upgrading," said study co-author Jordan Miller. "It's around $2,000 in parts to build OpenSLS, and adding the parts to an existing laser cutter and calibrating the machine typically takes a couple of days."
"In terms of price, OpenSLS brings this technology within the reach of most labs, and our goal from the outset has been to do this in a way that makes it easy for other people to reproduce our work and help the field standardize on equipment and best practices," said Ian Kinstlinger, study co-author.
"We've open-sourced all the hardware designs and software modifications and shared them via Github."
In terms of 3D printing, there are few technologies that can match the sintering process. Due to the way the emerging structure is printed, it is surrounded during sintering by powder, meaning that it is supported as it grows. Complex and otherwise impractical shapes can be produced with ease, and with little risk of structural failure during production.
"SLS technology has been around for more than 20 years, and it's one of the only technologies for 3-D printing that has the ability to form objects with dramatic overhangs and bifurcations," said Miller.
"SLS technology is perfect for creating some of the complex shapes we use in our work, like the vascular networks of the liver and other organs."
The research project demonstrated that the sintering process could print a series of intricate objects from both nylon powder and from polycaprolactone, or PCL, a nontoxic polymer that's commonly used to make templates for studies on engineered bone.
"The process is a bit like finishing a creme brulee, when a chef sprinkles out a layer of powdered sugar and then heats the surface with a torch to melt powder grains together and form a solid layer," Miller said. "Here, we have powdered biomaterials, and our heat source is a focused laser beam."
Slashing the cost and expanding the capabilities of sintering bodes well for the future of biomedical research, and Rice University’s decision to make the design open-source ensures that many facilities will benefit from this innovation.