The idea is simple - create an input device that relies on tapping your thumb against the inner sides of the fingers - the phalanges. Keeping the thumb independent and free to move, it has (4 fingers) * (3 phalanges per finger) = 12 combinations of a single tap gesture. Multiple taps can increase the number of key combination possible. I have the key mapping open-ended for now, but I am open to ideas.
I foresee this project to be useful both for non-differently abled and differently abled people.
I will create the first prototype for this project using capacitive touch sensing on a flexible PCB substrate mounted on every finger. If and when this is proved, the next challenge will be to do this without wearing anything over the finger.
The device would connect to the computer/mobile/tablet using either USB HID or BLE. Both are well-established for the purpose and the challenge I see is in making the sensing work.