This DC5V Humidifier USB Spray Module produces Mist by triggering a piezo plate at 108KHz .
It consists of a mini motherboard with Mosfet driving a piezo plate of 20mm.
This Ultrasonic Humidifier Piezoelectric Transmitter module works on the principle of cavitation produced by sound waves. Just provide the DC 5V power supply it will turn into a mini ultrasonic atomizer.
As sound waves contain compression and rarefaction. Due to extremely rapid movement, water droplets can no longer sustain their liquid state and get converted into vapor immediately. This vibration is produced by a piezoelectric filament.
Humidifiers are used  to add moisture to the air and can be used to treat a variety of conditions, including:Dry skin,respiratory problems,etc..
Humidifiers are widely used in MUSHROOM Farming to maintain Humidity at 90%.