The EPFL’s method draws on the principle of tomography, a method used mainly in medical imaging to build a model of an object based on surface scans.
“It's all about the light,” explained Paul Delrot, CTO of Readily3D, the company that has been set up to develop and market the system. “The laser hardens the liquid through a process of polymerisation. Depending on what we’re building, we use algorithms to calculate exactly where we need to aim the beams, from what angles, and at what dose.”
The technology could have a wide range of uses, but its advantages over existing methods may assist medical experts. Researchers believe the process could be used, for instance, to make soft objects such as tissue, organs, hearing aids and mouthguards. What's more, printing can take place inside sealed, sterile containers, preventing contamination.
“Conventional 3D printing techniques build parts layer by layer,” added Damien Loterie, CEO of Readily3D. “The problem is that soft objects made that way quickly fall apart.” What’s more, the process can be used to make delicate cell-laden scaffolds in which cells can develop in a pressure-free 3D environment. The researchers teamed up with a surgeon to test 3D printed arteries made using the technique. “The trial results were extremely encouraging,” Loterie said.
According to EPFL, the system is currently capable of making 2cm structures with a precision of 80 micrometres. However, the team believe that could be increased to 15cm in the future. “The process could also be used to quickly build small silicone or acrylic parts that don't need finishing after printing,” said Christophe Moser, head of EPFL's Laboratory of Applied Photonics Devices.