Figure 2

Planar capacitive architectures: (a) Design of the striped sensor (\(l=10\) mm; \(w=1\) mm; \(g=0.5\) mm); (b) Electrical schematic of the striped sensor; (c) Design of the circular sensor (\(d=6\) mm; \(q=10\) mm); (d) Electrical schematic of the circular sensor.