Photoelectrodeposition for 3D Printing

[sanman]

3D printers are receiving a lot of attention in the news these days, because they are seen to be a potential disruptive technology. However, most devices of this type are very limited in the materials they can work with, mainly fabricating models in plastics like PLA or ABS. Advanced high-end models which do work with metal (eg. Selective Laser Sintering or Electron Beam Melting) require a build chamber to either be under vacuum or else filled with an inert gas, in order to prevent oxidation of the metal being used to form the part/model.

Could laser-accelerated electroplating or electroforming be used as the basis for a 3D printing approach which additively fabricates macroscopic parts or models from metal? I emphasize macroscopic, because the method already seems to have been investigated for fabricating metal microstructures - but I'd like to know why it couldn't be used in conjunction with stereolithography to make larger metal structures on the order of many centimeters in length width and height?

Consider for a moment the much-heralded FormLabs Form1 3D stereolithography printer, which can manufacture plastic models using a UV-laser to solidify a UV-curable liquid polymer. A thin layer of liquid polymer is hit from below by the lasers, causing it to solidify wherever hit, and the resulting shape is slowly pulled out of that liquid layer from above:







It seems to me that a similar approach could be taken by using the method of laser-enhanced electroplating, and substituting the UV-curable liquid polymer for a solution of metal ions. By controlling where the lasers hit, an electroformed metal shape could be created and slowly pulled from the liquid layer from above.Now take a look at this:

http://books.google.ca/books?id=j3O...epage&q=laser enhanced electroforming&f=false

The development of laser-enhanced electroplating process offers a promising technique for high-speed and mask-less selective plating and/or as a repair and engineering design change scheme for microcircuits [300, 325-28]. For this, temperature is used to modify the position of the equilibrium potential in a localized region so that electro-deposition is driven by the potential difference between this region and the non-irradiated regions. Use of a focused argon laser beam (488nm) in an acid copper solution provided plating rates as high as 25µm/s [300]. Bindra et al [327, 328] discussed the mechanism of laser-enhanced acid copper plating and Paatsch et al [329] reported on laser-induced deposition of copper on p-type silicon. It was demonstrated that the increase in the plating rate under laser illumination results principally from photo-induced heating of the electrode surface [328].

I think a 3D printer based on electroplating/electroforming would be cheaper than existing metal 3D printers using SLS or EBM, because it doesn't require your build chamber to be under vacuum, or filled with an inert gas. And a theoretical build speed of 25µm/s seems quite significant - that's 1mm every 40 seconds, or 1cm every 400 seconds. Theoretically, you could print a 30cm tall model made of metal in 200 minutes - put all those old pennies to good use. Even if your real-world speed was only half that, it would still be quite competitive with existing 3D printing systems.

It seems to me that a 3D electroplating approach could bring 3D printing of metal parts into the home consumer market. After all, there are plenty of consumer-level home-electroplating kits sold to for people who plate their own jewelry, etc. So electroplating is not some exotic technology, and electroforming is just electroplating taken to greater lengths/thicknesses.

I'd like to know what if any limitations exist which would prevent or hinder laser-accelerated electroplating/electroforming from being scaled up from fabrication of microstructures to macro-sized metal parts.

 

[Guynemer]

I have been wondering about this as well, either by way of laser beams or perhaps an electron beam.