Thanks to everyone who was interested in my searches!
The study shows that the dimensions, thickness and rigidity of the plastic are in a rigid relationship and allow only small variations from the optimal values. I have placed one of the variants of the membrane cell. Unfortunately, I have not yet found 0.3mm plastic in the local availability and I do not have a 3D printer that is supposed to print transparent light-scattering elements. I am considering the issue of printing in a printing house with a solvent or sublimation printer.
The membrane shown contains three layers of polyester with a total thickness of 350 µm. The layer in the middle is a printed drawing 100 microns thick, laminated in an envelope with a film 125 microns thick. A tact button 2.5 mm high is placed in a hole in a washer of the same height, 10 mm in diameter. Pressing is clear. Unfortunately, the polyester "sandwich" has some permanent deformation, visible in oblique light.
Rigid backing like card plastic is needed, and we can't increase the thickness of the membrane more than 0.4-0.5mm
Your definitely choosing a more professional medium, as to my means frustratingly molding clay into a upper(negative) and lower press in which to shape plastic bags(very difficult) into the key shapes. Plastering old gel cyanoacrylate into a grid to layer a sturdy flat plastic piece(thin enough to use over a smartphone screen). I have messed about and yielded an ugly solution, but would much rather see your almost origami effect yield a worthy keyboard.
Erm... what? You've clearly had good results -- hence the photos in the Gallery. I wish I could do at least as well!
I'd be happy to make suggestions for improvement if I knew how you even did *those*. I have an inkjet printer, I don't know how to make it print on anything but various kinds of paper -- and I'm an artist!
This is entirely typical of Hackaday.io - An interesting project, with just a couple of photos, and the nothing. an empty void where information should be.
I will continue experimenting when I find some necessary materials. For example, plastic for cards is 0.3 mm. The results will be published immediately.
Your definitely choosing a more professional medium, as to my means frustratingly molding clay into a upper(negative) and lower press in which to shape plastic bags(very difficult) into the key shapes. Plastering old gel cyanoacrylate into a grid to layer a sturdy flat plastic piece(thin enough to use over a smartphone screen). I have messed about and yielded an ugly solution, but would much rather see your almost origami effect yield a worthy keyboard.