Piezoelectric Actuators

Piezoceramic actuators utilize the piezoelectric effect: A piezoceramic PZT material expands in the direction of the electrical field when voltage is applied to it. A piezoelectric actuator offers interesting solutions for micro-positioning, valve control, vibration damping and sound generation.

Actuators are electromechanical transducers and convert electrical signals into a mechanical displacement to regulate control systems. The conversion process is the focus of actuator technology. Electric field strengths of around 2,000 V/mm are usually required for an actuator deflection of 1.4 to 1.7.

CeramTec piezo actuators, however, consist of up to 500 roughly 0.1 mm thick piezoceramic lead zirconium titanate (PZT) layers made from the material SONOX^® P505 and are produced using specially developed stack and sintering processes. Thus, with CeramTec PZT actuators, the maximum elongation or displacement can even be achieved at relatively low voltages of 200 V. CeramTec manufactures such piezoceramic actuators with a square, rectangular or round cross section. The actuator can also be produced with a central or axial bore.

Actuator Micro-positioning for Optical Fiber Adjustment Optical fibers used as a medium of communication are only a few microns (μm) thick. If two optical fibers are to be connected when laying cable systems of this type, they must be exactly positioned to each other within a fraction of a micron. Linear piezoelectric actuators are ideal for this task because under electrical control they produce an actuation voltage proportional to the change in length that can be precisely regulated to 0.1 μm.

Actuator Micro-positioning for Precision Positioning Devices Micro-positioning devices are used wherever accurate positioning in one or more directions is necessary, e.g. in interferometry, laser applications and wafer technology. Depending on the design, up to three micro piezoelectric actuators are installed under tension in a zero backlash mechanical path transmission unit. A piezo actuator is used for each spatial direction and causes a relative motion of the system, which corresponds to its elongation plus the path transmission.

Piezoceramic Valve Control with piezoelectric Actuators
Ever shorter valve operating times are required in modern pneumatic and hydraulic applications. PZT-piezo-ceramic actuators with forces in the kN range and regulating distances of up to 50 µm offer an interesting solution. Due to the high energy densities that can be achieved, the required product of the force and the path can be achieved with a comparatively small piezo actuator volume. At less than 1 ms, the response times attainable are well below those for electromagnetic drives.