Mechanism

The mechanism for the thumb drive is a very simple friction based drive. The power that one puts through the top piece of the drive is translated directly to the hand on the bottom side, via an axle made of galvanised steel.
this is the draft version:

The idea of the discs is pleasure vs pain, with two opposite circles of velcro providing the different feelings. The pleasure is for the fiddling thumb on top, and the pain is on the bottom for the index finger.