Table 1.

The distances d and l between the needle electrodes as defined in Fig. 2.

Electrodes configuration	2 Fig. 2a	4 Fig. 2b	6 Fig. 2c	6 Fig. 2d, e	7 Fig. 2f, g
d [mm]	8.66	8.66	8.66	8.66	5
l [mm]	/	5	2.5	5	5