This Piezo element can be used as a vibration sensor by reading the voltage between its wires when it is knocked or tapped. The Piezo element will also act as a buzzer when an alternating or pulsed voltage is applied.
Our Code: SKU-000641
Supplier Link: [SparkFun MPN:10293]
Piezo elements come in handy when you need to detect vibration or a knock. You can use these for tap or knock sensors pretty easily by reading the voltage on the output. They can also be used for a very small audio transducer such as a buzzer.