Since its introduction, 3D printing has held out the promise of incredibly efficient and timely small-scale manufacturing but has been held back from widespread use by its slow speed.
A new technique developed at the University of Michigan, however, promises to print complex designs 100 times faster than current printers, possibly opening up the door for more widespread use.
How 3D Printing Works
The way 3D printers work is by reading a file of a 3D model and reconstructing the model by laying down resin in tiny lines, set down in layers, one on top of the other, until the model is constructed.
The bigger the model, however, the more time consuming this process becomes, growing exponentially as the model gets wider and taller.
What’s more, if you needed to produce many copies of the 3D model, as you would for small scale manufacturing, you would need more machines, often hundreds more, printing out the same item.
This is little better than traditional manufacturing processes, and so the industry hasn’t had much incentive to adopt 3D printing on a large scale.
Overcoming the Time Barrier
It’s not as if the incentive for 3D printing in manufacturing doesn’t exist. For manufacturing jobs requiring less than 10,000 copies of an item, 3D printing would be a drastic improvement over creating special molds that can cost as much as $10,000.
With manufacturers needing products to roll out within a week or two, 3D printing just cannot fill these orders without becoming cost ineffective.
“Using conventional approaches, that's not really attainable unless you have hundreds of machines," according to University of Michigan associate professor of chemical engineering, Timothy Scott.
Scott, along with Mark Burns, the T.C. Chang Professor of Engineering at the University of Michigan, developed a new technique for 3D printing that seeks to overcome this time barrier. Their approach has produced incredible results, providing an increase in production speed of 100 times standard 3D printing techniques.
Creating a Vat-Printing Solution to the Time Challenge
Burns and Scott tried something very different from traditional printing techniques to achieve their results. Rather than laying out the finished product a line of resin at a time, they used a pair of lasers to solidify the liquid resin in a vat into the shape prescribed by the 3D model file.
The lasers are able to control where the resin remains liquid and where it solidifies, allowing them to make sophisticated shapes, including a toy boat, a block with the letter M carved into it, and a lattice.
Getting the lasers to print exactly what was required was no small task. Earlier attempts resulted in premature solidification of the resin at the window of the vat, where the laser first made contact with the resin.
Gaining Precision Control With More Lasers
Earlier attempts used only one laser, so Burns and Scott tried adding another laser, using a different wavelength to control the rate of resin flow and were able to achieve 3D control of resin hardening close to the vat window, whereas previous vat-printing approaches were restricted to a 2D plane.
“It's one of the first true 3D printers ever made," said Burns.
Patents have been filed for the various techniques used in the process and Scott is planning a commercial venture based on their work.