This project was completed by Donovan New as part of his undergraduate thesis at Pomona College in the physics and astronomy department. This information was last updated May 3, 2019.

This instructable provides the 3D printing files and arduino code used to create a wearable energy harvester whose power output is monitored by a data logger. This allows one to quantify the energy harvested from human motion using piezoelectricity. The design includes an onboard Arduino with SD card data logger. A speaker can be included for real-time audio feedback in addition to gathering data on the amount of electricity generated in each trial.

Step 1: Parts

This project is designed for the following piezoelectric bimorph transducer:

Mide PPA-2011 ($274)

For the Arduino, we used the Uno Rev3:

Arduino ($22)

For logging the data, we used the Adafruit SD card writer:

Data logging shield ($17 including headers)

One also needs additional parts (SD card, load resistor, smoothing capacitor, rectifying bridge, 9 V battery for powering the arduino, small nuts and bolts, and jumper wires/connectors).

Step 2: Lab Test Apparatus

The files attached here can be used to 3D print a clamp that holds the generator on top of an oscillating post.

Step 3: Field Test Apparatus

The two .stl files attached here can be used to 3D print the case for holding the generator and datalogger.

The .iso file attached here contains the arduino sketch used for data collection.

An image of our final circuit is shown.

Example data are shown for the output (in volts across a 20 kOhm load resistor after rectification, with a 10 microFarad smoothing capacitor) for various activities.