Figure 2

Ionic conductivity in a micro-channeled cantilever determined by impedance spectroscopy. (a) Schematic illustration of the setup with equivalent circuit. The electric model is based on a modified Randles circuit with constant phase element (CPE). (b) SEM image of the cross-section through a micro-channeled cantilever. (c) Normalized impedance in dependence of aperture state (‘open’ vs. ‘blocked’) and externally applied pressure at 0.1 mM and 150 mM ionic strength, respectively, and pH 4. The impedance has been measured at a frequency of 0.1 Hz and normalized to the open aperture state without applied pressure. (d) Bode plot for the open and blocked cantilever aperture at 0.1 mM ionic strength and (e) corresponding Nyquist plot. (f) Bode plot for the open and blocked cantilever aperture at 150 mM ionic strength and (g) corresponding Nyquist plot. Solid and dashed lines are fits to the shown equivalent circuit.