libre braille devices

Chao. I have been having an idea to develop a braille device something like this:

1. Looks like an iPad or such. But it has countless projections on its surface instead of a screen.

2. The projections move up and down like some braille devices do.

3. Entirely libre hardware by default.

I think that reading by fingers is faster and more efficient than listening the reader's voice such as Orca.
And since people can touch and read any point on the screen freely without order, I think it is more like seeing the screen.

I know that there are few projects to develop the latest braille devices. If you search for the web, you would be able to see some pictures of those, one of them seemed very similar to of the idea above. I have sent some emails to some projects but it seems that some of them came to deadlocks.
And there are already some kinds of braille devices, and some of them seem to be useful, but some of those seem ridiculously expensive. I guess that maybe the developers rely on a subsidy, so they would set the prices so high but it does not seem to be so healthy.

I would like to know the current precise situations of braille devices world. Would someone who is familiar with it mind telling me the information? I wonder if there is already such a braille device. But even if there is, it probably would not respect your freedom. Thank you.