Looks like fun. Reminds me of experiments done many years ago to provide "sight" to blind people by having arrays of actuators press on the skin of their backs. I wonder what ever happened to that.
Bach-y Rita P, Collins CC, Saunders F, White B, Scadden L.(1969). "Vision substitution by tactile image projection.". Nature, 221:963–964.
That's actually a very old tech. I have worked with similar 7-segment numeric displays. It's very expensive, and subject to mechanical wear.
Fun service problem: We had one display that never did work right in a scrap yard. After about eight months we realized it worked fine when they weren't operating the crane with the scrap pickup magnet. The flip digits are very finely balanced to minimize the coil current necessary to flip them, and from a hundred feet away the crane magnet would flip the scoreboard digits. We put in one of the then-new superbright LED displays and never had another problem. Nowadays we never see the flip digits any more.
There is still a marke for electro-mechanical where very big signs need constant update and the power wasted in LED lights is an issue. Well lit airports, subway stations, and train station still are using this techonology.
After all, why increase your electric bill just to have something that is very pretty?
erco
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Bach-y Rita P, Collins CC, Saunders F, White B, Scadden L.(1969). "Vision substitution by tactile image projection.". Nature, 221:963–964.
Fun service problem: We had one display that never did work right in a scrap yard. After about eight months we realized it worked fine when they weren't operating the crane with the scrap pickup magnet. The flip digits are very finely balanced to minimize the coil current necessary to flip them, and from a hundred feet away the crane magnet would flip the scoreboard digits. We put in one of the then-new superbright LED displays and never had another problem. Nowadays we never see the flip digits any more.
After all, why increase your electric bill just to have something that is very pretty?