Piezo Shower / Self-heating Shower

The shower uses water as only energy source.
It encourages less energy consumption.
The inner surface of its tubes is covered with piezoelectric nanofibers, which generate electric charges with the water's friction. These are transformed into heat to rise the water's temperature.
To maximize the surface in touch with the water, it's built with a prolific structure that resembles the circulatory system.
It's controlled through a waterproof display that also shows elapsed shower time and amount of consumed water.