When [DonHo] sang about tiny bubbles, he probably wasn’t thinking of them embedded in glycerine. But that’s where the bubbles in [ShinodaY]’s clock reside. The viscous fluid holds the bubbles better allowing the time to be read more easily. You can watch the relaxing display in the video below.

The theory of operation is simple and reminds us somehow of a reverse Tetris game. Solenoid valves at the base release air bubbles to form a row of the display. The bubbles rising makes room for the next row. The display has as many columns as there are air outlets at the bottom. Spacing the bubble pixels is as simple as adjusting the timing between air bubbles.

An ESP8266 controls the whole thing thanks to an I/O expander. Some Neopixel LEDs make the whole thing look cooler.

This is the second version of the clock. The first version (see the second video, below) used water, and we think you’ll agree the glycerine makes all the difference.

The project is as much aquarium work as electronics. We also had to wonder what else you could display like this? Maybe some crude graphics or tweets? Perhaps using it as a form of interesting game would be cool, especially if it were significantly scaled upwards.

For example, we remember one very large bubble display (note: the outbound link has changed). You can even make a 3D display — sort of.