With the Canute Braille Display inching its way closer to a commercial release, I got to digging into how it actually works. This led me around to a 36 minute presentation by Russell Couper from 2016, one of its developers [here] where he talks about the various prototypes and approaches they went though while working out of a local hacker space in Bristol.
Interestingly, the device is mechanical and appears to use a stepper motor per horizontal row to rotate gears, with bars placed vertcally across the rows that slide forward and backward to configure the braille pins. The real meat of the presentation starts around the 8 minute mark.