If a voltage is applied to the top surface and the ceramic disc, the ceramic expands and the disc becomes thicker with a smaller diameter. To generate an electric field, the flat area on the disc’s top surface must be metalized. This increases its performance and lets it operate across a wider temperature ranges, thanks to its symmetry.īender actuators are used in circular knitting machines, reading devices for those with bad eyesight (Braille modules) and pneumatic valves-especially proportional valves for pressure and flow control.Ī disc transducer consists of a thin ceramic disc bonded to a metal substrate. It has a second ceramic layer sandwiching the substrate. One variation on the bender actuator is called the trimorph. Typical characteristics include deflection of several tenths of a millimeter and forces up to 1 N. One end of the actuator is usually fixed, so motion gets converted to a bending movement.īender actuators can be designed to have a range of possible forces and motions, and they are well-suited for use in pneumatic valves. This piece is also joined all along one side to a conductive substrate. Piezo elements can be crafted into several types of actuators, depending on what the needs are: disc transducers, bender actuators or piezo stacks.īender actuators are rectangular with a piece of piezo ceramic material that has been rendered conductive on both surfaces. In applications that need to be extremely energy-efficient, it is even possible to recover the charging energy when the drive is reset and then use it again for the next charging operation. ![]() Electrical power is calculated as voltage × current, so the power is zero if no more current flows. Current only flows while the capacitor is charging, and flow drops to zero when charging is complete. In electrical terms, a piezo element is a capacitor consisting of two electrically conductive plates and the ceramic piezo material between them acting as a dielectric. ![]() This is one advantage of piezoelectric valves and drives. These shape changes can be harnessed to power a drive and be created using almost zero power. Using strong electric fields, engineers can give some ceramics piezoelectric properties that make them change shape when a voltage is applied. They found some materials, usually ceramics with conductive surfaces, convert electrical energy into mechanical energy and vice-versa. The piezoelectric effect (from the Greek word for “pressing”) was discovered in 1880 by the brothers Jacques and Pierre Curie, the latter being the husband of Marie Curie. ![]() This lets them generate mechanical motion and be used as oscillators. The inverse piezoelectric effect, precisely the opposite, forces piezo elements to change shape when a voltage is applied to them. Piezo elements are electromechanical transducers that convert mechanical forces (pressure, tensile stress or acceleration) into voltages.
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