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Piezoelectric balance presented by Pierre Curie to Lord Kelvin, Hunterian Museum, Glasgow. Piezoelectricity (/ ˌ p iː z oʊ-, ˌ p iː t s oʊ-, p aɪ ˌ iː z oʊ-/, US: / p i ˌ eɪ z oʊ-, p i ˌ eɪ t s oʊ-/) [1] is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in ...
The converse piezoelectric effect (CPE) describes how an applied electric field will create a resultant strain which in turn leads to a physical deformation of the material. This effect can be described through the constitutive equations. [ 4 ]
When a voltage or an applied electric field stresses a piezo element electrically, its dimensions change. This phenomenon is known as electrostriction, or the reverse piezoelectric effect. This effect enables the element to act as a translating device called an actuator. Piezoelectric materials are used in power actuators, converting electrical ...
PVDF molecules contain two hydrogen and two fluorine atoms per repeat unit, so they have a choice of multiple conformations. However, rotational barriers are relatively high, the chains can be stabilized into favorable conformations other than that of lowest energy. The three known conformations of PVDF are all-trans, tg + tg −, and tttg ...
Dielectric EAPs are materials in which actuation is caused by electrostatic forces between two electrodes which squeeze the polymer. Dielectric elastomers are capable of very high strains and are fundamentally a capacitor that changes its capacitance when a voltage is applied by allowing the polymer to compress in thickness and expand in area due to the electric field.
The piezoelectric effect is exhibited by crystals (such as quartz or ceramic) for which an electric voltage across the material appears when pressure is applied. Similar to pyroelectric effect, the phenomenon is due to the asymmetric structure of the crystals that allows ions to move more easily along one axis than the others.
The change in the spontaneous polarization results in a change in the surface charge. This can cause current flow in the case of a ferroelectric capacitor even without the presence of an external voltage across the capacitor. Two stimuli that will change the lattice dimensions of a material are force and temperature.
Quartz is one member of a family of crystals that experience the piezoelectric effect.The piezoelectric effect has found applications in high power sources, sensors, actuators, frequency standards, motors, etc., and the relationship between applied voltage and mechanical deformation is well known; this allows probing an acoustic resonance by electrical means.