**3. Applications of piezoelectricity**

All the electrical devices nowadays are just not limited to electrical connection in between them but have this piezoelectricity as a common thing in all applications. Cell phones, diesel fuel injectors, grill igniters, ultrasonic transducers, acoustic guitar pickups, vibration sensors, certain printers, and musical greeting cards etc. utilizes piezoelectricity. The additional development of manmade piezo materials which includes piezoelectric ceramics.

The applications of piezoelectricity includes the following fields:


#### **3.1 Piezoelectric effect works with sensors and motors**

To start with, the electric cigarette lighters and gas grills have a high voltage power source when compared with other applications of the piezoelectric effect. In these cases, a hammer strikes a piece of piezo material, which then produces enough current to create a spark that ignites the flammable gas in its presence. However, in other applications like sensors, the hammer is typically replaced by other forms of energy like sound waves - including ultrasound, as hammer is an exciter of the piezo material.

process of detonation occurs, the air/fuel charge explodes instead of burning smoothly thereby damaging the engine. Eventually, this is why the designed engines with conservative operational margins at the expense of efficiency — it was

With the advancement of the better control systems, the relevant engine parameters may be adjusted in real-time to maximize efficiency and power. If detonation begins to occur, piezoelectric knock sensors can be employed to sense the detonation before it becomes problematic. This gives control systems time to

In almost all the applications the measurement of dynamic pressure changes, using piezoelectric pressure sensors yields more reliable results than using conventional electromechanical pressure sensors (**Figure 3**). The reason behind this is that piezoelectric devices have a high frequency response and signal conversion without any need of bellows, diaphragm, or any type of mechanical linkage in conjunction

Sonar Equipment depends especially on piezoelectric sensors to transmit and receive ultrasonic "pings" in the 50-200 kHz range. Along with an ideal frequency response for such applications, piezoelectric transducers have a high power density that enables large amounts of acoustic power to be transmitted from a small package. For instance, a transducer that is only 4″ (100 mm) in diameter may be capable

to avoid this notorious problem.

*Piezoelectricity and Its Applications*

*DOI: http://dx.doi.org/10.5772/intechopen.96154*

make the required adjustments.

with a strain gage or displacement sensor.

of handling power output greater than 500 watts.

*3.2.2 Pressure sensors*

*3.2.3 Sonar equipment*

**Figure 3.**

**79**

*A piezoelectric pressure sensor.*

When these are working with sensors, piezo materials will detect even some of the minute disturbances and anomalies, which will make them unique and idealistic devices in industrial nondestructive testing and medical imaging.

In the other perspective, piezoelectric motors can perform highly precise and repeatable movements. This inbuilt makes them excellent devices (**Figure 2**) for the precision movements of sensitive optical devices like telescopes and microscopes.

#### **3.2 Piezoelectric sensors in industrial applications**

The industrial sector contributes its applications with piezoelectric sensors for a variety of uses. Some common, everyday uses include:

#### *3.2.1 Engine knock sensors*

Engine manufacturers are every now and then facing challenges related to the control of engine devices. Under some non-supporting situations, gasoline engines are susceptible to an undesirable phenomenon known as detonation. When the

**Figure 2.** *Traveling wave motor.*

## *Piezoelectricity and Its Applications DOI: http://dx.doi.org/10.5772/intechopen.96154*

process of detonation occurs, the air/fuel charge explodes instead of burning smoothly thereby damaging the engine. Eventually, this is why the designed engines with conservative operational margins at the expense of efficiency — it was to avoid this notorious problem.

With the advancement of the better control systems, the relevant engine parameters may be adjusted in real-time to maximize efficiency and power. If detonation begins to occur, piezoelectric knock sensors can be employed to sense the detonation before it becomes problematic. This gives control systems time to make the required adjustments.
