Piezoelectric crystals for fuel injectors

[Monster]

Well many of you guys are familiar with these piezoelectric crystals, they are mentioned on all those press release documents when a new diesel engine or D.I engine is launched. I am not sure if you guys have seen one of those so today I found one from work and took some dodgy photos with my camera phone. These crystals are responsible for the opening and closing of the nozzle of a fuel injector. The crystal expands when a electric current passes through them and basically pushes the nozzle open. For this particular crystal, the maximum expansion is around 30 microns or 0.03mm, so it is hardly visible.

It looks and feels like a normal block of metal but it is made from ceramic material. The first pic shows the actual crystal



These 2 pic shows another crystal with blue insulation tape and wires attached to both sides. This particular one broke during some injector testing.

[wolfram]

These things suck current, even more than the old solenoid. But of course, they are much more flexible in turns of injection shaping.