Along these lines, a current Kickstarter project, which uses a 3D printer and a saltwater jet in a very clever way to ablate metal electrochemically. It even presents the prospect of doing metal deposition printing by reversing the process/current (skip to 9:50).
https://www.kickstarter.com/projects/athenatech/liquid-blade...
To be clear, if you read Hacker News you owe it to yourself to watch the entire Applied Science back catalogue; without exception every video is fascinating.
Is clear that the guy has some money to invest in those experiments. But apart from that, what he does, is so many different topics, is just mind blowing.
Even if I had the money and space he has, I could never ever do what he does.
From some videos is clear how much perseverance he has, often he reports about months and months of failure after failure, until he succeeds. I think THAT is the most impressive part of his videos, and what I try to learn from.
One of the few points maintaining faith in humanity; is there are companies happy to pay you that money if you can do what he does.
In his case, google.
Looks like the photochemical part is for the mask. The rest is a applied chemical etch.
I remember laughing so hard the first time I saw the video, and he said:
"... the nightmare scenario here is: you've got this super powerful pump, you know, making 30 or 40 PSI, at gallons per minute flow rates of hot ferric chloride; and if one of those things bursts, I mean the mess is just going to be beyond spectacular.
okay let's press the start button..."
I wish every engineer would aspire to be like him. He is truly worthy!
this has been used in aerospace for a long time, and while making the process accesable, it does nothing for the engineering and validation required to offer complete solutions