Stanford's new 3D printing tech is up to 10 times faster than the quickest printer

The developments in the field of additive manufacturing continue unabated. This time, Stanford University's new burst will bring further innovation to the industry.

Engineers at Stanford University have created a 3D printing process that is 5 to 10 times faster than the fastest high-resolution printer currently on the market and can use different types of resin to create a single object.

Published in Science Advances on September 28, the results demonstrate that the novel process is much faster than the quickest high-resolution printing method currently available. It also probably allows researchers to use thicker resins with better mechanical and electrical properties.

“This new technology will help to fully realize the potential of 3D printing,” says Joseph DeSimone, the Sanjiv Sam Gambhir Professor in Translational Medicine and professor of radiology and of chemical engineering at Stanford and corresponding author of the paper.

“It will allow us to print much faster, helping to usher in a new era of digital manufacturing, as well as to enable the fabrication of complex, multi-material objects in a single step.”

It was started in 2015

The new design enhances continuous liquid interface production, or CLIP, a 3D printing technique developed by DeSimone and his associates in 2015.

A rising platform gently removes the object, which appears to be fully formed, from a thin resin pool in a process known as CLIP printing. While a layer of oxygen hinders curing at the bottom of the pool and produces a "dead zone" where the resin remains in liquid form, a series of UV pictures transmitted through the pool harden the resin into the proper shape.

The secret to CLIP's speed is the dead zone. The liquid resin is designed to fill in behind the solid item as it rises, enabling smooth, continuous printing. However, this isn't always the case, particularly if the resin is exceptionally sticky or the object rises too quickly.

The researchers have put syringe pumps on top of the rising platform for this new technique, known as injection CLIP, or iCLIP, to add extra resin at strategic locations. 

“The resin flow in CLIP is a very passive process – you’re just pulling the object up and hoping that suction can bring material to the area where it’s needed,” says Gabriel Lipkowitz, a Ph.D. student in mechanical engineering at Stanford and lead author on the paper.

“With this new technology, we actively inject resin onto the areas of the printer where it’s needed.”

Well-known structures from several nations

With iCLIP, you may print with different types of resin at varying stages of the printing process by injecting more resin individually. Each new resin just needs its own syringe.

Three separate syringes, each filled with resin colored in a different way, were used by the researchers to test the printer. They were successful in printing models of well-known structures from several nations in the colors of each nation's flag, such as Independence Hall in the red, white, and blue of the United States and Saint Sophia Cathedral in the blue and yellow of Ukraine.

“The ability to make objects with variegated material or mechanical properties is a holy grail of 3D printing,” Lipkowitz says.

“The applications range from very efficient energy-absorbing structures to objects with different optical properties and advanced sensors.”

Abstract:

In additive manufacturing, it is imperative to increase print speeds, use higher-viscosity resins, and print with multiple different resins simultaneously. To this end, we introduce a previously unexplored ultraviolet-based photopolymerization three-dimensional printing process. The method exploits a continuous liquid interface—the dead zone—mechanically fed with resin at elevated pressures through microfluidic channels dynamically created and integral to the growing part. Through this mass transport control, injection continuous liquid interface production, or iCLIP, can accelerate printing speeds to 5- to 10-fold over current methods such as CLIP, can use resins an order of magnitude more viscous than CLIP, and can readily pattern a single heterogeneous object with different resins in all Cartesian coordinates. We characterize the process parameters governing iCLIP and demonstrate use cases for rapidly printing carbon nanotube–filled composites, multi material features with length scales spanning several orders of magnitude, and lattices with tunable moduli and energy absorption.