More Metal Printing Experiments

The RepRap team continue to develop methods of printing electrical conductors. If they succeed, it would be possible for future 3D printers to print objects that include (at least at first) simple electronic circuits embedded directly in their shapes. One can imagine a wide variety of LED lamps or switchboxes emerging quickly once this tech is available, for example.

 

But is it available? Rhys Jones described RepRap's recent experiments in a long post detailing the steps they've taken. While the mechanics of 3D printing electronics would be mostly identical to printing in plastic or food, the extruder and material are what's really different. 

 

They've been testing electrically conductive materials with these characteristics: 

 

• Reasonable melting point, similar to the plastic currently used in 3D printers
• Significant viscosity to enable extrusion
• Low surface tension effect to ensure accurate deposition during printing

 

But problems emerged, mainly that their metal extruder (brass) slowly dissolved in the molten metal material and new approaches had to be developed. Eventually they used a hi-temp PTFE nozzle liner and a low-melt point alloy of 57.5% Tin, 41.3% Bismuth, 1.2% Indium that successfully achieved printing the conductive traces above. 

 

This is by no means a ready-to-use technology; They're still working on it, and there is also the question of sourcing this peculiar mix of metals in printable filament. However, this is how all new technology appears, and if it works, we may see it on your desktop sometime in the future. 

 

Via RepRap

3D Printed Curvilinear Antennae

Researchers at the Frederick Seitz Materials Research Laboratory at Illinois have achieved something never before accomplished: printing an electronic antenna onto a curved surface. Why would you want to do this? According to electrical and computer engineering professor Jennifer T. Bernhard: 

 

These antennas are electrically small relative to a wavelength (typically a twelfth of a wavelength or less) and exhibit performance metrics that are an order of magnitude better than those realized by monopole antenna designs. 

 

Printing in this way is quite different than the layer-by-layer approach typically used in 3D printing. Instead the print head must scurry along the curved surface so precisely that it doesn't mess up the smooth and uniform deposition of the electrically conductive material. The very short video is quite interesting to watch. 

 

However, this raises an interesting idea: does 3D printing really need to be done layer-by-layer? Or can print heads move up and down as necessary to permit more printable object geometries? Obviously, extremely precise motion is required, but the Illinois team's work demonstrates this is possible. 

 

Via Engineering at Illinois and YouTube

PC Board Printed

We just noticed this development that was posted last July: a RepRap 3D printer was used to print a circuit board. Well, not completely - the 3D printer actually printed the etch resist, which protected the conductive bits from the acid bath. The resulting board was then cleaned up and had components mounted on it. 

 

The 3D printing process was actually 2D: a marker pen was guided by the RepRap over the virgin board to outline the electronic traces. Two passes were required to produce a sufficient amount of resist. 

 

There are several approaches to electronic printing, but it's great to see another successful one. 

 

Via UltiMachine

Ponoko's Electronics

Distributed manufacturing service Ponoko has added some new materials to their shelf. Actually a *lot* of new items, and they are electronic! No, you're not printing or extruding electronics, but instead they are selectable components that can become part of your creations. The list of components is astonishingly long, ranging from fourteen different styles of accelerometer to twenty-four Zigbee wireless units. In all, there's apparently 1500+ electronic components available to choose from. 

 

What does this mean? For starters, you can now manufacture (in the case of Ponoko, this means buying an instance of someone else's creation) or sell a creation that includes electronic features. Can you imagine the amazing toasters that will emerge? All levity aside, we believe electronics will bring a massive new wave of creations to the Ponoko market. If your imagination was blown out before, you'd better upsize it yet again. 

 

Via Ponoko (Hat tip to Derek)

Get Ready for Printed Electronics

We were all quite impressed when the RepRap printer managed to reproduce itself some months ago. But in fact the reproduction was only of its structural members, whereas the metal bits and electronics were not actually reproduced. No worries, it will eventually happen. Metal printing has emerged in several 3D print services, but what about the electronics? It's hard to do because conductive material typically has very high melting points - so high that it would burn or melt surrounding 3D printed material if you tried to print the wiring.

Recently a big step towards electronics printing occurred. Xerox has invented a new type of "Silver Ink", purportedly for 2D inkjet-style printing. However, we suspect this might also be ideal for 3D printers. Imagine an Objet printer (capable of handling two different print materials simultaneously) loaded with plastic and "silver ink". You could theoretically print objects with embedded (albeit simple) electronics. Well, wiring at least.

Via PhysOrg (Hat tip to Micah)

Battery Printing

 

Leslie Gordon of Machine Design.com writes on the possibilities of printing electronics, and specifically batteries.

We all know that 3D printers can easily create cases for electronics, but what about the electronics themselves? This is difficult to achieve on traditional one-material-at-a-time 3D commercial printers, but experiments being undertaken by the fab kit makers is beginning to yield some results. According to Gordon, it's now possible to print a battery:

Researchers developed a battery with zinc as the anode and air as the cathode because of the design’s simplicity.

First came development of a zinc-powder suspension that did not clog the syringe nozzle. Next came designing the separation layer between the anode and cathode. In commercial batteries, this layer is often paper. In contrast, the layer in the zinc-air battery is made from ceramic slurry or a synthetic resin.

These 3D printed batteries are apparently only half the capacity of commercial equivalents, but it's definitely a great start. We think the most interesting aspect would be the ability to print batteries of any shape - suitable to include within designs with limited volume.

Via Machine Design.com