A new 3D printing method of structures imitating biological tissues

Solutions on the border of medicine and innovative technologies are gaining more and more popularity. Scientists from the University of Colorado Denver and the South China University of Science and Technology have developed a method of 3D printing in DLP technology of structures imitating biological tissues.

The innovative material is a liquid crystal elastomer (LCE) resin that resembles honey in consistency. The material is used for printing in DLP technology and allows the production of porous, openwork geometries. The lattice structure of the print resembles cartilaginous tissue and has shock-absorbing properties, which gives many possibilities for use in surgical and protective equipment.

The liquid crystal elastomer resin is an anisotropic material that combines the features of liquid crystals with the flexibility of a crosslinked polymer. LCE has the ability to dissipate energy and shows high flexibility. Thanks to the possibilities of additive technology, you can adapt the print geometry, providing control over the mechanical properties of the material.

Creating products with LCE has been difficult so far. Previous techniques allowed for making large products with low accuracy or microscopic elements with high precision. Using 3D Digital Light Processing (DLP) printing technology, scientists have created relatively large structures compared to the products currently available from light-cured elastomer resin. The new material allows to produce elements in high resolution that can be successfully used for a variety of applications

The team printed several structures, including a fine and detailed lotus flower model and a spine stiffening prototype, creating the largest LCE model with such high precision. A compression test of this model revealed that LCE has a 27-fold higher energy dissipation depending on stress. This result is much higher than in the case of Stratasys TangoBlack resin or neoprene, which is a commonly used cushioning material. What’s more, the material gives the possibility of creating prints on ordinary DLP and SLA printers.

The project is supported by the U.S. Army Research Laboratory and US Army Research Office, NSF CAREER Award and research and development program managed by the laboratory at Sandia National Laboratories for the US Department of National Security for Nuclear Safety.