Each group needs:

• 1 piezo transducer/piezo element, such as: SparkFun https://www.sparkfun.com/products/10293
• 4 diodes, type PH4148, 1N4148 or 1N914, such as: SparkFun https://www.sparkfun.com/products/8588
• 1 electrolytic capacitor 220 μF or greater (25 to 50 V), such as: SparkFun https://www.sparkfun.com/products/8982
• 1 switch (switch choice may alter wiring diagram), such as: rocker switch from SparkFun https://www.sparkfun.com/products/10727 
• 1 LED, such as: LED light bar from SparkFun https://www.sparkfun.com/products/12014
• 1 breadboard, such as: from SparkFun https://www.sparkfun.com/products/9567
• 2 alligator clips, such as: a 10-pack of alligator test leads from SparkFun https://www.sparkfun.com/products/12978
• 1-3 breadboard jumper wires, such as: a 10-pack at Sparkfun https://www.sparkfun.com/products/8431

To share with the entire class:

• multimeter, such as: 15-range digital multimeter at https://www.amazon.com/RadioShack-22-182-15-Range-Digital-Multimeter/dp/B00CSMDGS6
• 22 AWG wire, 1 ft per group, such as: 25-ft spool at SparkFun https://www.sparkfun.com/products/8022; note: a higher AWG, such as 24-30, if available, works better in the breadboard sockets
• soldering gun, to prepare materials for the activity
• tiny screwdriver
• ability to show students a few short online help videos
• projector to show students the How to Build a Piezoelectric Generator Presentation, a PowerPoint® file

Cost note: Everything in this activity can be reused. The initial ~$20 cost per group can be continually reused for other classes. Ordering from SparkFun Electronics is the least expensive option (better than RadioShack); the company gives a 10% discount when purchasing 10 or more of any item. One exception is the switch; the RadioShack switch has been tested and shown to work, while the SparkFun one has not.