Air Load piezoelectric transducers

Examples of the air load transducer are buzzer, siren and piezoelectric fan. The buzzer transducer is the audio frequency bending type vibrational device. The transducer is used to generate the sound, voice and music. The areas of applications are the audio instrument and electronic devices, such as door bell, stopwatch and speaker. The latest product of such device is the multilayer type piezoelectric speaker for mobile phone applications. The advantages of such product are the low input voltage, low power consumption, no electromagnetic field and slim size.  

The piezoelectric fan is also a bending type transducer. It could be used for cooling applications in electronic devices. One of the designs of such devices is shown below. It consists of a bending transducer and blade. The bending transducer actually works as a shaker which produces the resonance of the blade. Due to the large vibration amplitude of the blade, air is forced to blow in the direction as shown in the figure. Advantages of such devices are good reliability, no wearing parts, low weight, thin profile, instant starting with no power surge, low magnetic permeability and almost no heat dissipation.