Silk And Wood Inspire Revolutionary Liquid Crystal Polymer 3D Printing

Fused deposition modeling (FDM), or 3D printing, has slowly started seeping into a variety of sectors offering new and improved ways to approach everything from car manufacturing, to robotics, to space aircraft engineering, to art. With every introduction of a new 3D printing technology come ever increasing possibilities.

Now, researchers at the Complex Materials group and the Soft Materials group at ETH Zürich have developed a novel bioinspired approach to 3D printing ideal for the manufacturing industry. The innovative technology allows for the generation of recyclable liquid crystal polymers (LCP) that are on par and even better than the best state-of-the-art printed polymers and high-performance lightweight materials.

Revolutionizing manufacturing

Best of all, the material can be developed even through the use of cheap desktop printers. The work is now set to revolutionize the manufacturing industry by enabling the cheap and efficient mass production of complex parts. 

Before this development, the poor mechanical performance of FDM-produced parts severely hindered the adoption of 3D printing for mass customization and production uses. Previous efforts to sequentially deposit beads of a molten polymer were ineffective as the resulting products were usually weak and exhibited poor adhesion capabilities.

Past attempts to resolve this issue experimented with putting to use the freedom in design provided by 3D printing in fiber-reinforced composites. But these approaches could, at the time, only be performed through the use of expensive specialized equipment, meaning they were simply not commercially viable.

They were also restricted to the printing of only non-recyclable material. This is where ETH Zürich's technique offers the most promise.

A first in 3D printing

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For the first time in 3D printing history, researchers were successful at creating objects from a single recyclable material whose mechanical properties beat all other available printable polymers, even performing in par with fiber-reinforced composites.

In order to come up with their novel FDM solution, ETH Zürich's team sought inspiration in nature. More specifically, they looked at how spider silk and wood form during their development.

They analyzed the molecular alignment of these biomaterials' proteins and found a way to reproduce it in 3D printing in order to give their resulting objects the same unrivaled mechanical properties of silk and wood. 

"By orienting the molecular domains with the print path, we are able to reinforce the polymer structure according to the expected mechanical stresses, leading to stiffness, strength and toughness that outperform state-of-the-art 3D-printed polymers by an order of magnitude and are comparable with the highest-performance lightweight composites," reads the study.

More importantly, these structures can be created without the labor- and energy-intensive processes involved in today's dominant composite manufacturing technologies. All that is required is an easily-accessible readily-available polymer and a simple cost-effective commercial desktop printer.

The groundbreaking technology will surely have countless novel structural, biomedical and energy-harvesting applications, forever changing the role of 3D printing in manufacturing.