Hacham-
IF this type of keyboard — that doesn’t involve circuits when pressed — were used on Shabbos (without typing – just using the arrow keys and <Enter>), what issur (if any) would transpire that would prevent the usage of a computer (that was already on) via this technology on Shabbos?
This is basically a type of touch-screen technology (there are a few types).
This means that the keyboard itself isn’t having circuits closed and opened, but rather the current is increasing and decreasing.
As far as the halachic ramifications of this current altering, I don’t know.
Even if the current fluctuation isn’t as problematic as closing and opening a current, which normal keyboards do, there is still the issue of electronic components that are probably closing and opening circuits, too.