Posted November 16, 2015

3D printing with nanoparticles

A Dutch startup is determined to revolutionize building electronic circuits and various other products. They use a patent pending process in which building blocks of many possible materials are grown from loose atoms up to almost any desired size. This way you can build a circuit by laying down just what you need, instead of etching away almost everything. Advantages are many.

The startup is based in Delft and is called VSParticle (Very Small Particle). Co-founder Aaike van Vugt is a former student of the Delft University of Technology. 'Our process was invented by prof. Andreas Schmidt-Ott, who also is a co-founder. We can use any material that conducts electricity. By generating sparks between two rods we vaporize some material into a cloud of single atoms. Then these atoms start sticking together to form multi-atom particles. We have learned to stop this growing at any time, so we can have particles any size we want.'

VSParticle's process needs to take place in an atmosphere that contains as little oxygen as possible, since many fine-grained metals tend to oxidize quickly. But contrary to competing processes the company can use room temperature and normal atmospheric pressure.

'We can use metals like copper, aluminum, ruthenium but also carbon and silicon,' says Van Vugt. 'By compressing conducting and non-conducting materials together we can even in some cases produce non-conducting materials. As a company we are now developing a printer that can lay down the copper connections for electronic circuit boards. We can print tiny metal wires on any surface, even plastic or paper. That's why our process could become useful in the production of wearable and flexible electronics.'

'We used to generate particles at 200 sparks a second but last year we managed to scale that up to 10,000 sparks a second. One unit can now process on the order of grams of material per hour.'

Compared to traditional production of electronics, this process should have many advantages. For one thing, there's hardly any waste. 'You don't need to cover a surface in copper and then etch away all the copper you don't need with dirty and toxic chemicals. You have less production steps, less machinery, a smaller cleanroom,' explains Van Vugt. 'You can make prototypes a lot faster.'

Printing lines is like 1D, or 2D at best. So how about 3D printing? Van Vugt: 'We are learning and developing, so we started producing relatively simple copper lines. But since it's really a print head that we use, and since we can use many materials, we consider 3D semiconductor electronics, and things like sensors, to be real possibilities. Complete microprocessors are some way off. It'll take us years to reach the required precision.'

Outside electronics Van Vugt is also looking at chemical catalysts, the kind you need in things like batteries and fuel cells. 'These consist of small particles on some carrier material. We could manufacture that. I'm thinking of microbatteries, the kind that could become important as a power source for the Internet of Things.'

About Herbert Blankesteijn

Herbert Blankesteijn is a technology journalist from the Netherlands who has written for many prominent Dutch newspapers. He presented and directed television and radio programmes and has 10 books to his name. Herbert is interested in nascent fields such as 3D printing, drones, robotics and the private space business.