Medical 3D printing in the subject of a new paper from the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland discussing the possibility of endoscopic 3D printing inside the body.
Paul Delrot, team leader at EPFL, explains, “With further development our technique could enable endoscopic microfabrication tools that would be valuable during surgery,”
“These tools could be used to print micro- or nano-scale 3D structures that facilitate the adhesion and growth of cells to create engineered tissue that restores damaged tissues.”
Put a needle on it
The needle seen in pictures is an optical fiber, which is key to achieving fine resolution. To print, the fiber is dipped in a photopolymer ink which is then written and cured layer by layer to create a structure.
The idea with the EPFL approach is that it should be used together with a 3D printing technique that creates “bulk parts.” Together, Delrot says, “multi-resolution additive manufacturing could be achieved.”
A competitor for two photon lithography?
EPFL’s technique produces structures at a scale close to two photon lithography techniques. The chief differences between the two methods is that the EPFL device is more compact and, by using a constant instead of a pulsed laser, maybe significantly cheaper.
The resolution that can be created by an optical fiber is also coarser than state-of-the-art two photon lithography systems, but Delrot maintains that “it is potentially sufficient to study cellular interactions.”
Nanotechnology in medicine
Despite the apparent high cost of two photon lithography, the technology is still a popular method of 3D printing for medical research.
With a Nanoscribe Photonics Professional GT, researchers have managed to create novel micro swimmers and tetrapods for directed drug delivery in the body. Such equipment is also let out for lease as part of lab memberships creating another potential loophole for the cost.
Towards the future
In order to advance the work of both techniques in healthcare, there is a need for development of more biocompatible photopolymers.
The EPFL device in particular also needs improvements to the scan speed, and the researchers must look at how to post process microSLA structures in the body.
Delrot concludes, “Our work shows that 3D microfabrication can be achieved with techniques other than focusing a high-power femtosecond pulsed laser,”
“Using less complex lasers or light sources will make additive manufacturing more accessible and create new opportunities of applications such as the one we demonstrated.”
The EPFL micro 3D printing method, “Single-photon three-dimensional microfabrication through a multimode optical fiber“, is detailed in the online publication of Optics Express journal. It is co-authored by Paul Delrot, Damien Loterie, Demetri Psaltis, and Christophe Moser all of the École Polytechnique Fédérale de Lausanne.
Featured image shows the optical fiber micro 3D printing system at the École Polytechnique Fédérale de Lausanne. Photo via The Optical Society