Working on the Mark XIII keyboard. This one will have the keymodules connected together with a matrix of stiff-ish copper wires, covered over in polycapralone. The theory is that people will be able to change the shape of their keyboard by heating it up using a hot air blow dryer. That will soften the polycapralone, which gets quite soft, and won't hold up its own weight, hence the copper wires. The keyboard owner can push the keymodules around until they're in the perfect position for them. The copper wires will hold the shape until the polycapralone hardens, making the keyboard both flexible and stiff, soft and hard, as needed.
Here are a set of keymodules, soldered to a small PC board, with a
brass strip used as a barrier against the polycapralone. Without the barrier,
the polycapralone would stick to the keys and/or jam up the key movement.