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Comment by petermcneeley | Hacker News Reader

I tried out the multi electrode approach about 15 years ago. My work was based on the original work of John D. Madden https://people.ece.ubc.ca/mm/papers/Madden_JMES_1996.pdf

I can find my paper and post it but keep in mind it was a "undergraduate thesis" and something I spent only a very finite amount of time on.

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Yah, please post it! Can you speak to the minimum resolution and wear rate/lifetime with single electrode approaches?

I would imagine resolution mostly comes down size of electrode and how close you can get that to the substrate and grow the deposit in a controlled fashion. Mine were 25um. As for wearing out the electrode; madden's paper probably has some information. I would expect the wear to be similar to the oxygen side of electrolysis (water).

https://darkcephas.github.io/MELED_paper/MELED_paper.pdf

Thanks, interesting read.

i'd forgotten all about madden's work! thanks for this!

how did your project go?

I actually got to meet Madden multiple times and he even gave me access to his lab. My physics profs were very impressed by my project but I was disappointed. This electro deposition effect is a bit like lightning and didnt work well with my theories about trying to use a multielectrode head with different voltages to produce a shaped potential.

yeah, i've been thinking about that too. how did you model the field?

I dont think there was any rigor in modeling of the field. I did this entire project as one semester as one of my last undergrad courses. I wish I had more time and resources for the project but by then I knew I was headed outside the university into software development.

https://darkcephas.github.io/MELED_paper/MELED_paper.pdf

From what I heard the state of the art was to move away from electrodes and to use lasers. So how that works is that you have the normal electrolytic solution but you apply a passive voltage below the activation voltage. Then you use the laser to break down the double layer at the substrate surface. This leads to laser controlled deposition.

neat! i was wondering if that would work last week

i feel like it's probably easier to have 1000 electrodes than 1000 lasers tho

Optics may help to reduce the amount of lasers.

Wonder if using the same approach that resin printers use would work?

• SLA resin printers use a superfast/accurate motorised mirror to direct the laser where its wanted

• mSLA resin printers use a strong light source instead of a laser + an LCD to mask the area they don't want exposed

(another issue about lasers is that laser focal spots are pretty big)

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