====Actuator technology==== related: [[Sensor Technology]], [[Human Interface System]] ====Selected types==== * electric motor * brakes * pneumatic (air) * hydraulic (water) * Shape memory alloy (metal, as lina described) * piezoelectric * piezoelectric pressure valve: http://www.acx.com/lab/cool_piezo.html ====Shape memory alloys==== Heat dissipation and response time may be significant impediments. Sample kits available through hobbyist sites. By the meter, this stuff is rather cheap (£5 per meter, roughly) http://www.dynalloy.com/sampleapplications ====Additional links on SM alloy==== http://www.smst.org/smstweblinks.html http://www.robotstore.com Including numerous kits and a text: "Actuator Design Using Shape Memory Alloys", as well as off the shelf integrated shape memory alloy actuators (20 cost 8000¢, or 100 cost 300 USD) These have 20 mm displacement, and one pound pull