Source: topView extends BufferedApplet      

Top view

Instructions: Move disks with mouse
Toggle rate with SPACE bar

A stirring movement beneath the table powers all movement. Each object periodically engages with this stirring movement during some phase of the stirring cycle. This causes the object to shift its position on the table.

Objects are manipulated by a roving collection of electromagnets which reside below the table surface (see next diagram). When a new object is placed on the table, the nearest free electromagnet is assigned to it, based on proximity.

The rate of stirring has been slowed down here to illustrate the mechanism. In practice the stirring rate can be many cycles per second, resulting in smoother motion.

Source: sideView extends BufferedApplet      

Side view

Instructions: Move blue disk via mouse or arrow keys
Toggle rate with SPACE bar

In the scenario to the left, the blue disk is always carried back to the center of the table.

The object to be moved has a ferromagnetic metal base. Under the table's top surface is an inner surface containing ferromagnetic metal. This inner surface makes a continuous stirring movement. An electromagnet below the surface is periodically switched on and off. When switched on, the electromagnet clings to the inner surface and moves together with it, dragging the object along by magnetic attraction.