3D Printer technology creates artificial arteries from opaque resin

A team of engineers at the Swiss Federal Institute of Technology Lausanne (EPFL) has developed a 3D Printer method that uses light to make objects from opaque resin in seconds. This breakthrough may have promising applications in the biomedical industry, such as making artificial arteries. The research was recently published in the journal Advanced Science.

Back in 2017, engineers at EPFL’s Laboratory for Applied Photonic Devices (LAPD) designed a 3D Printer that can make objects almost instantaneously. Five years later, the team has improved their printing equipment and method to produce objects made from opaque resins that were previously impossible.

EPFL’s 3D Printer is one of the fastest printers in the world. Most 3D Printers work by depositing material layer by layer, a process known as additive manufacturing. EPFL, however, uses the volumetric method, in which resin is poured into a container and rotated. The engineer irradiates the container with light from different angles so that the energy accumulated in the resin cures when it exceeds a given level. This is a very precise method that allows items to be manufactured at the same resolution as existing 3D Printer technology.

This volumetric method can be used for objects of almost any shape. It took engineers just 20 seconds to create a tiny figurine of Yoda from Star Wars, compared to about 10 minutes by a traditional manufacturing process.

Light is able to cure the resin by interacting with the photosensitive compounds contained in the plastic. Engineers say the new method only works if the light passes through the resin in a straight line without being strayed, which is not the case in opaque resins. To this end, they devised a solution.

First, they used a camera to observe the trajectory of light through the resin, and then adjusted the calculations to compensate for the light distortion. They also programmed the printer to run calculations and correct the light, which ensured that the machine had the right amount of energy to cure the resin. As a result, engineers were able to print objects in opaque resin with almost the same precision as transparent resin, a major breakthrough.

As a next step, the engineers hope to be able to use the new method to print several materials at the same time and increase the printer’s resolution from a tenth of a millimeter to a micrometer.