Artificial tank

This Artificial octopus tank combine art , Science and electronics project.
Art - Octopus. Its 3D printed and the Arm is make of series of
beads. The number or the weight of beads is important
such that when put in the water, it just float.
Science - It makes use of density, Archimedes principle or air
compression.
It will sink when the air on top of the tank is compressed.
It make use of magnet to stir the water.
Electronics - There is no battery inside the tank and still able to light
up.
It make use of wireless coil to transfer from a coil
outside the tank to the coil inside the tank.