Electrostriction (or magnetostriction) is the phenomenon in which the shape of a material changes in response to the application of an electric field or a magnetic field. The effect has been known since the 19th century, when it was first reported in certain metallic alloys by William Thomson, or Lord Kelvin.
The phenomenon of electrostriction works because of the difference in response of different metals and alloys to electrical fields and magnetic fields. When subjected to an electrical field, certain metals and alloys will stretch in the direction of the applied field while others will contract. Similarly, when subjected to a magnetic field, certain materials will expand or contract in the direction of the field. In certain cases, the effects of electrostriction are reversible and can be used to generate mechanical force or motion.
The effects of electrostriction are important in a number of technical applications. It’s used in linear actuators, transducers and rotary motors, among other things. Electrostrictive materials are used in loudspeaker diaphragms, where changes in the electric field across the material cause the diaphragm to move, producing sound. Electrostriction can also be used to produce movement in sonic accelerometers, which measure vibration. The effect is also used to produce actuators in precision positioning equipment.
The force generated by electrostriction is relatively small compared to other forms of energy. Nevertheless, it can be used in applications where precision positioning is required. For example, it’s used in prosthetic devices, automobile window lifts and hydraulic pumps.
By controlling the electric field and the magnetic field across the material, different types of electrostriction can be produced. Piezoelectric materials, for example, produce expansion and contraction when subjected to an electric field, while magnetostrictive materials produce expansion and contraction when subjected to a magnetic field. The degree to which materials expand or contract depends on their electrostrictive coefficient, which is a measure of their sensitivity to the applied fields.
The research and development of electrostrictive materials is an active area of research and development. Many different types of materials are being investigated, including metallic alloys, polymers and ceramics. The objectives are to design materials that are both sensitive and durable, with high electrostrictive coefficients and low hysteresis. Research is also being conducted into ways to increase the force generated by the effect.
In recent years, nanomaterials have also been studied as possible electrostrictive materials. Carbon nanotubes, graphene and quantum dots, among others, have been investigated and shown to possess electrostrictive characteristics. Such nanomaterials show great promise, and researchers are hopeful that the effects of electrostriction can be harnessed to create new and improved actuators for a variety of applications.
In summary, electrostriction is a phenomenon that involves the expansion and contraction of materials in response to electric and magnetic fields. It is used in a variety of applications, including linear actuators, transducers and rotary motors, and is also studied for use in nanomaterials. Research into electrostriction is ongoing, and promising developments are being made all the time.
