Figure 8(b)). The reverse direction is the -By direction. Figure 8(f) shows the front and back single electrode output signals 605, 606 when the front finger slides towards the +x direction and the back finger simultaneously towards the - x direction, followed by the front finger sliding towards the -x direction and the back finger simultaneously towards the +x direction. Similarly, when the front finger slides towards the +y direction and the back finger slides towards the - y direction, the object is programmed to rotate one step in the - direction (as shown in Figure 8(b)), with the reverse direction for the + rotation. Figure 8(g) shows the front and back single electrode output signals 607, 608 when the front finger slides towards the +y direction and the back finger simultaneously towards the - y direction, followed by the front finger sliding towards the -y direction and the back finger simultaneously towards the +y direction. For + or - control (as shown in Figure 8(b)), the front finger slides consecutively across -x and -y, or conversely -y and -x. Figure 8(h) shows the front single electrode output signal 609 when the front finger slides consecutively across the -x and -y directions, followed by sliding consecutively across the -y and -x directions. Again, during the measurements, the fingers are lifted and moved back into the centre each time. When the finger is not sliding across a specific pattern, whether it is on the surface or in air, the signal is 0 . Accordingly, 0 level is measured between the sliding motions as seen in the graphs. Therefore, through the elegant, thin and flexible card design of device 500 according to an example embodiment together with a suitable controlling strategy, manipulation of an object in 3D free space can advantageously be achieved. It is noted that a single electrode design, compared to e.g. the two electrodes design in the card controller device 500, can also be used for 3D control in different embodiments, where different grating structures are used for the electrode grids, e.g. on each of the sides of the card. Then the electrodes on