[Cyborg] tiny haptic actuators

[Tomm]

The idea of using tiny solenoids instead of pager 
motors came up today.  Here is a solenoid in a 
TO-5 package, but at 1/2" by 1/2", it's still not 
small enough (found using "worlds smallest 
solenoid" as search term)
http://www.lineelectric.com/solenoids/wssolenoid.html

I also found this interesting gaming vest that 
simulates being shot (solenoid in the side), 
knifed (vibration motors on shoulder blades), or 
injured (Peltier junctions)
http://iroboticist.com/2010/03/26/tgv/

That got me thinking: rather than injury 
simulation, I think what game players would prefer 
is a way of getting additional information about 
the state of the game through haptics.  Perhaps 
northpaw ankle bracelet could be repurposed to 
point towards the nearest teammate or visible game 
opponent?  As we agreed, HUDs are challenging to 
use in a first-person shooter (operator overload), 
but perhaps an ankle bracelet that vibrates only 
when there's a teammate in front of you (so you 
don't shoot them) would be a sellable product?  
Serious gamers are willing to spend hundreds of 
dollars to get an edge.  Jus' sayin'...

Instead of a solenoid, I'm thinking a 
piezoelectric material might be a better choice 
for small size, and also lends itself better to 
arrays:
http://en.wikipedia.org/wiki/Electroactive_polymers

Lots of possibilities here... l have some PVDF 
(good piezoelectric polymer) lying around, will be 
it to the next sensebridge meeting to play around 
with.

Anyone have thoughts or experiences with other 
small haptic actuators?

     Tomm