When only the front side of device 500 is connected, output voltage on 100 load and short circuit current of 128 V and 3.7 can be achieved, see Figure 28(a)_ and 28(d). Similarly, when only the backside is connected, output of 100 V and 3.35 is achieved, see Figure 28(b) and 28(e). Then when both sides are connected in parallel, a total output of 145 V and 6.85 can be achieved, see Figures 28(c) and 28(f). 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 both sides can be connected together into one single electrode to perform 3D control using a suitable signal detection from the (connected) single electrode. Example 3 To determine a suitable electrode width and spacing for sensors 1100, 1200, 1600, measurements with both electrode width and spacing varying from 6 mm to 2 mm were conducted, as shown in Figure 34, which shows: (a) Schematic of the electrode patterns for the measurement. The generated output peaks from the 8/2/8 mm and 6/2/6 mm electrode patterns under finger sliding in a (b) slow, (c) normal, and (d) fast manner. The generated output peaks from the 8/4/8 mm and 6/4/6 mm electrode patterns under finger sliding in a (e) slow, (f) normal, and (g) fast manner. According to the experimental results, it was concluded that certain electrode width and spacing are preferable for the finger sliding application. Typically, electrode spacing of 6 mm can achieve clear signal identification with separated output peaks. To decide the electrode width for large and small electrodes, measurements as shown in Figure 29 were conducted. The schematic in Figure 29(a) indicates that two sets of large/small/large electrode patterns with different dimensions were connected together and investigated under three sliding speeds (slow ~38 mm/s, normal ~97 mm/s, and fast ~152 mm/s). The