I've been researching parts for a while relating to non-vibration based haptic output... so far what I've found are solenoid type devices, electro static output

I've been researching parts for a while relating to non-vibration based haptic output... so far what I've found are solenoid type devices, electro static output (TENS units for example) or resonant actuators, but things like tactile displays used for braile for example are too cumbersome in construction to really be useful as skin contact points. anyways just an idea from another hacking type who'se been thinking about the subject.