Piezoelectric Lab Report

orientation of a piezoelectric material during the design and manufacture of a device. There are certain mechanical parameters which plays a great role in piezoelectric effect.

2.2.1 Mechanical Strain The mechanical strain S which results from the application of a stress T is linearly proportional to the compliance S (S-1= Young’s modulus) within the elastic deformation region of the stress-strain curve of the material (below the yield strength ) T=c S
Strain is a dimensionless property which describes the changes in length of a material, defined as the length under stress divided by the equilibrium length (no stress) of the material.
With knowledge of the yield strength of a
However, in other cases, a non-zero set point may be more appropriate; for example, in temperature-sensing, a reasonable neutral environment might by 0 Celsius or room temperature. As the sensitivity of the system will be greatest at the synchronous frequency, the synchronous frequency accordingly is measured. It should be noted that the electrical input signal should have a frequency equal to the synchronous frequency of the device to maximize efficiency. If the measurand causes the synchronous frequency to shift, a system without feedback control on the input frequency will experience a slight signal attenuation. The important parameters in determining the synchronous frequency of the device is the pitch p of fingers of the IDTs. For simplicity, we shall examine the most common IDT design which utilizes 1:1 interdigitation and equal spacing between all fingers on both sides. The pitch of the fingers is then the spacing between two fingers on the same side of the electrode. As consecutive fingers (alternating sides of the IDT) are always at equal but opposite voltage assuming a sinusoidal (AC) signal, consecutive fingers mark the location of maximal strain alternating between tension and compression. As such, the wavelength of the wave transduced by the piezoelectric substrate will be equal to p. The following
The most common are quartz (SiO¬¬ ) and lithium tantalate ( ), and to a lesser degree, lithium niobate( ).Each material has specific advantages and disadvantages, which include cost, temperature dependence, attenuation, and propagation velocity. Table I lists some relevant specifications for each material, including the most popular cuts and orientations . An interesting property of quartz is that it is possible to select the temperature dependence of the material by the cut angle and the wave propagation direction. With proper selection, the first-order temperature effect can be minimized. An acoustic wave temperature sensor may be designed by maximizing this effect.Other materials that have commercial potential include gallium arsenide (GaAs), silicon carbide (SiC), langasite (LGS), zinc oxide (ZnO), aluminum nitride (AlN), lead zirconium titanate (PZT), and poly vinylidene flouride