The piezoelectric actuators convert an electric signal into precise physical movements used by high precision equipment as machining tools for lens and mirrors. It is also used in the hydraulic valve control, in the low volume pump activation (as inkjet printers), as also many other applications.
There are different kinds of Piezoelectric Actuators. The ones manufactured with discreet piezoelectric elements or co-forged are used in the equipment that provides micro positioning, mechanical stabilization and vibration control, for optic fibers among others. The construction is made in a natural format (covered only by isolation material), or capsulated in stainless steel, protecting it from mechanical damage and environmental effects.
Assembly of a slim piezoelectric ceramic piece to an inactive substrate builds the Unimorph Actuator. Energizing of this set brings the deformation of the whole structure.
The Bimorph is built through the of two or more piezoelectric ceramic pieces so that with the length alteration of the multiple units can produce relativity large movements. It is assembled by two transversal expansion sheets hold together as to the applied voltage to the electrodes deform the sheets to the opposite way of each other, resulting in a bending movement. The bimorph movement by the voltage applied is than multiplied, being that way many times larger than the movement of a single sheet actuator. As it is bimorphs act as levers offering larger displacement.
These are many piezoelectric elements displaced mechanically in series and electrically in parallel. The displacement of each element is added to the total displacement, and the stack movement is the sum of each element movement. This kind of actuator is generally used in applications that require large displacement.