What is it?
A device to clean utensils.
What is it made of?
Ultrasonic transducer.
How does it work?
The dishes to be washed is kept immersed in water.
The ultrasonic sound waves produced inside water, vibrates the water molecules in ultrasonic frequency range.
Any impurity in contact with utensils comes off because of the push and pull effect of water molecules vibrating.
Benny's science blog 