How to charge TiO2 particles for a DIY e-paper capsule? - Page 1
Forum section: electronics / projects

author: kapton
author_rank: Newbie
timestamp: September 09, 2019, 06:49:20 pm
content: Greetings,I'm trying to make a single e-paper capsule (1cm x 1cm) at home. At first, I tried to charge the TiO2 particles by putting them in H2O with NaOH and then putting that whole solution in baby oil, but it turns out I shouldn't have any water in the whole process. I also tried adding a surfactant (liquid soap) but it also has water. Water is a problem because it forms micelles around the TiO2 particles and prevents proper spreading. How do I charge the TiO2 particles without water (and NaOH). What oil-soluble surfactant I can use that doesn't contain water? Does anyone know any details about how the chemicals of the e-paper display work?I researched a lot and it turns out the big companies use complicated processes and mixing different chemicals with expensive lab machines to produce the desired charged TiO2 solution. Is there any way I can do it at home?

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 10, 2019, 01:30:16 am
content: Well, I don't know.I've seen a russian guy experimenting with that, but he cannibalized a used eink panel:http://we.easyelectronics.ru/HomeTech/izgotovlenie-segmentnogo-indikatora-na-elektronnyh-chernilah-v-kartinkah.htmlDoing that completely from scratch seems involved, but do not hesitate to share if you make any progress - sounds like interesting stuff.

author: amyk
author_rank: Super Contributor
timestamp: September 10, 2019, 11:40:33 am
content: Processes are probably half in trade secrets and the other half patented... but if I were trying to replicate, I would look at the early history that's recorded in scientific journal articles.

author: kapton
author_rank: Newbie
timestamp: September 10, 2019, 03:39:03 pm
content: The engineering is already known,https://www.researchgate.net/publication/232414208_Fabrication_of_charged_particles_for_electrophoretic_displayit's just too complicated for a 17 year old to do at home without the budget and proper equipment. My last option is to try to contact anyone who has and may have access to such fluid and ask if that person can send me some for my project.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 10, 2019, 03:44:24 pm
content: Quote from: kapton on September 10, 2019, 03:39:03 pmIf you're ok with using ready-made fluid, why not do like the russian guy and reuse parts of an old e-ink panel (you can probably find broken/for parts eBook readers on eBay for cheap) just for the fluid and upper protective layer, and just design your own bottom, electrode layer?

author: kapton
author_rank: Newbie
timestamp: September 10, 2019, 04:38:54 pm
content: The idea is pretty good. Do you happen to know where I can buy broken cheap e-paper displays/e-readers?

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 10, 2019, 04:52:25 pm
content: Well, look up "ebook for parts" and "ebook defective" on eBay, you will find some.

author: kapton
author_rank: Newbie
timestamp: September 10, 2019, 04:56:25 pm
content: I did it, but I couldn't find anything cheap.

author: kapton
author_rank: Newbie
timestamp: September 10, 2019, 04:57:33 pm
content: I think it will be cheaper to just buy e-paper displays. Can you link to a specific page or item?

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 10, 2019, 05:51:38 pm
content: https://www.ebay.com/itm/1-54-inch-ePaper-152x152-Smallest-e-Ink-Display-Panel-White-Black-with-UC8151C/293178013844

author: mrflibble
author_rank: Super Contributor
timestamp: September 11, 2019, 05:45:26 am
content: Somewhat related, and interesting in its own right, a video by Ben Krasnow (Applied Science on youtube) on sputtering a thin TiO2 layer onto glass:And to the OP: he also has a bunch of videos on those black/white/red e-paper displays. For example this one:

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 11, 2019, 03:04:29 pm
content: Quote from: kapton on September 10, 2019, 04:57:33 pmWell, apparently you can find quite a few broken ebook readers from US sellers, and not that many from elsewhere... so the shipping cost will often be a problem.Otherwise, look for "eink panels" on Aliexpress. Not that cheap unless you buy very small ones, but they will be new and may not be more expensive than a broken ebook reader + shipping.Now for something really crazy with e-ink:https://shopkits.eink.com/product/31-2%cb%9d-color-epaper-display-ec312tt2/