A great idea

Indeed, trying to pull an "Apple" by stealing others' concepts and seducing gullible investors is a great idea.

As for the product itself, it's existed for at least the past decade in various guises - I'm pretty sure Jaycar sold such a pen at one stage, though I can't seem to find it on their web site now.

Here's an example of one which has been around for a while;

Chinese wholesale web sites have a veritable cornucopia of related products.

Perhaps the DIY approach would be cheaper:

Though getting the chemicals would cost a lot initially.

Using the ink in an InkJet printer as in the research paper that article is based on would be best. Still an expensive experiment though, especially if you have to buy the printer as well.

I'm not sure it's all that reliable either so point to point soldering would still be my preferred prototyping method. Would be interesting to try though, making your own conductive ink.

I wonder if the print heads would last beyond a single session.

Bah, bugger this new-fangled stuff.

Blank PCB + (thin!) permanent marker + HCl + H2O2 = rapid-enough prototyping.

Worked great for me back in my student days, no reason why it wouldn't work great now. Easy enough to tidy up blunders too - just keep some alcohol swabs handy.

Of course, you could go the easier route of using FeCl instead of the haphazard HCl+H2O2 mix, but back in my day (in my location), we didn't have the luxury of FeCl.

Making PCB's is the step after the real prototyping is done ;-)

Hmm, it makes me think of the many "Happy" hours I spent at a drawing board with Letraset blobs and narrow black sticky tape fixing the mistakes that the "Real draughtsmen" had made.

Real men don't need breadboards :-P

hehe

emember the old K-Tel bottle utter" "Make a set of fashionable glass from your old wine and beer bottles"?

There was a UK kickstarter for yet another one of those a few months ago.

Far less that the ingredients to make the ink; basic mono is all you need.