In order to keep the operating voltage within practical limits, Piezo actuators consist of thin layers of electroactive ceramic material electrically connected in parallel. The maximum electrical field Piezo ceramics can withstand is on the order of 1 to 2 kV/mm. Actuators made of this ceramic are often referred to as Piezo actuators. Lead zirconate titanate (Piezo) based ceramic materials are most often used today. Modern piezo ceramics capable of greater motion replace the natural material used by the Curies, in both types of devices. Two main types of piezo actuators are available: low voltage (multilayer) devices requiring about 100 volts for full motion and high voltage devices requiring about 1000 volts for full extension. With high-reliability Piezo materials a strain on the order of 1/1000 (0.1%) can be achieved this means that a 100 mm long Piezo actuator can expand by 100 micrometers when the maximum allowable field is applied. ![]() Piezo motion devices require no maintenance because they are solid state and their motion is based on molecular effects within the ferroelectric crystals.Piezo devices act as capacitive loads and require very little power in static operation, simplifying power supply needs.Piezo devices can be designed to move heavy loads (several tons) or can be made to move lighter loads at frequencies of several 10 kHz.There are no moving parts (no "stick-slip" effect). Repeatable nanometer and sub-nanometer sized steps at high frequency can be achieved with Piezo devices because they derive their motion through solid state crystal effects. ![]() Piezoelectric actuators (PZTs) offer the user several benefits and advantages over other motion techniques: Actuators using this effect first became available around 20 years ago and have changed the world of precision positioning. For nanopositioning, the precise motion which results when an electric field is applied to a piezoelectric material is of great value. The first commercial applications were ultrasonic submarine detectors developed during World War I and in the 1940’s scientists discovered that barium titanate ceramics could be made piezoelectric in an electric field.Īs stated above, piezoelectric materials can be used to convert electrical energy into mechanical energy and vice versa. ![]() After the discovery it took several decades to utilize the piezoelectric phenomenon. This effect is referred to as the inverse piezo effect. Later they also verified that an electrical field applied to the crystal would lead to a deformation of the material. ![]() In 1880, Jacques and Pierre Curie discovered that pressure applied to a quartz crystal creates an electrical charge in the crystal they called this phenomena the piezo effect. The word "piezo" is derived from the Greek word for pressure. For more detailed information see Fundamentals of Piezoelectricity and Piezo Actuators. When AC voltage is applied, the piezoelectric material moves at the frequency of the applied voltage and the resulting sound is loud enough to wake even the strongest sleeper. Furthermore, alarm clocks often use a piezoelectric element. For example, in small butane cigarette or gas grill lighters, a lever applies pressure to a piezoelectric crystal creating an electric field strong enough to produce a spark to ignite the gas. The piezoelectric effect is often encountered in daily life.
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