Micro 3-D Printer Creates Tiny Structures in Seconds

Nanoscribe, a spin-off from the Karlsruhe Institute of Technology in Germany, has developed a tabletop 3-D microprinter that can create complicated microstructures 100 times faster than is possible today. “If something took one hour to make, it now takes less than one minute,” says Michael Thiel, chief scientific officer at Nanoscribe.

While 3-D printing of toys, iPhone covers, and jewelry continues to grab headlines (see “The Difference Between Makers and Manufacturers”), much of 3-D printing’s impact could be at a much smaller scale. Micrometer-scale printing has shown promise for making medical and electronic devices.

Thiel says it should be possible to speed up his company’s microprinting technique even more in the future. Nanoscribe plans to start selling its machine in the second half of this year.

Printing microstructures with features a few hundred nanometers in size could be useful for making heart stents, microneedles for painless shots, gecko adhesives, parts for microfluidics chips, and scaffolds for growing cells and tissue. Another important application could be in the electronics industry, where patterning nanoscale features on chips currently involves slow, expensive techniques. 3-D printing would quickly and cheaply yield polymer templates that could be used to make metallic structures.

So far, 3-D microprinting has been used only in research laboratories because it’s pretty slow. In fact, many research labs around the world use Nanoscribe’s first-generation printer. The new, faster machine will also find commercial use. Thiel says numerous medical, life sciences, and nanotechnology companies are interested in the new machine. “I’m positive that with the faster throughput we get with this new tool, it might have an industrial breakthrough very soon,” he says.

The technology behind most 3-D microprinters is called two-photon polymerization. It involves focusing tiny, ultrashort pulses from a near-infrared laser on a light-sensitive material. The material polymerizes and solidifies at the focused spots. As the laser beam moves in three dimensions, it creates a 3-D object.

Today’s printers, including Nanoscribe’s present system, keep the laser beam fixed and move the light-sensitive material along three axes using mechanical stages, which slows down printing. To speed up the process, Nanoscribe’s new tool uses a tiny moving mirror to reflect the laser beam at different angles. Thiel says generating multiple light beams with a microlens array could make the process even faster.

The smallest features that can be created using the Nanoscribe printer measure about 30 nanometers, says Julia Greer, professor of materials science at the California Institute of Technology.

“This is very challenging to do, and the Nanoscribe tool excels at it,” Greer says. “I don’t think there is another company out there that is capable of such precision.” Greer’s research team uses the first-generation Nanoscribe printer to create and study materials that could be used for catalysts and to make strong, lightweight structures, but she acknowledges that its slowness is a drawback.