Figure 2
(a) Impedance magnitude spectrum of an acoustophoretic device (chip G1) with different media inside the microchannel: (1) air, (2) water and (3) 20% CsCl solution. The measurements show differences in local regions of the spectra, indicating that the channel medium affects the system electrical response. A zoom - in highligths the region of the spectra where there is a significant deviation between the spectra. The deviation can be seen as a frequency shift in the direction indicated by the arrow and is related to the changed resonance frequency linked to the corresponding media loaded in the microchannel. (b) Normalized Differential Spectrum (NDS) water vs 20% CsCl. (c) NDS water vs air. It can be seen that the NDS water vs 20% CsCl presents two clear peaks. Instead, the noisier NDS water vs air does not give any clear indication of a channel resonance.
