This project explores piezoelectric and thermoelectric technologies to design a self-sustaining mobile power bank that harnesses wasted thermal and kinetic energy.

To provide a clean energy source without interfering with phone usage, the power bank should be placed on the back of the smartphone rather than the screen.

First, a thermoelectric generator chip will be positioned on the back of the phone, near its CPU, where most of the heat is generated. The hot side of the generator chip will be placed against the phone, while the cold side will be exposed to air. This setup helps mitigate overheating during heavy phone use or hot weather.

However, to ensure an optimal temperature difference, a heat sink is necessary. A water container will be placed on top of the thermoelectric generator. This water container serves another purpose: by placing piezoelectric films inside the water, any movement or sound waves will cause the films to bend and vibrate, enabling them to convert kinetic energy into electrical energy.

The materials used include:

• Matrix thermoelectric generator
• PZT thin, flexible piezoelectric film
• Pure water (to prevent short circuits)
• Flexible TPU (for 3D printing the design case)

These materials are readily available, affordable, and easy to work with.

This application benefits all smartphone users by enhancing battery life, harvesting excess thermal energy, stabilizing phone vibrations, and providing clean energy that contributes to environmental sustainability. The design will be marketed to smartphone manufacturers for integration into future phone models.