Fig. 4: Measurements of acoustoelectric fields’ spatiotemporal characteristics in a physiological phantom.
From: Remote focused encoding and decoding of electric fields through acoustoelectric heterodyning
Spatiotemporal characteristics of the electric field generated by simultaneous application of a focal acoustic pressure field P(x,y,z) at a frequency fA = 500 kHz propagating in the \(\hat{z}\) direction and an electric field \(\overrightarrow{E}(x,y,z)\) at a frequency fE = 8 kHz. Measurement setup same as in Fig. 3a, but with the measurement probe scanned across the volume. a and b The applied electric field is parallel to the propagation direction \(\hat{z}\) of the applied acoustic field. a Spatial distribution of the measured electric potential VAE (normalized to max value) in the radial plane \(\hat{x}\hat{y}\,\) at the black dashed line in (b) shown at different phases θ of the acoustic period (\(1/{f}_{{\rm {A}}}\)), together with the simulated distribution (as in Fig. 2b). b Spatial distribution of the measured electric potential VAE in the axial plane \(\hat{x}\hat{z}\). c and d The applied electric field is perpendicular to the propagation direction \(\hat{z}\) of the applied acoustic field, shown are as in (a) and (b). e Line plot comparing the measured electric potential VAE normalized to max value along the black dashed lines in (b) and (d). f Acoustoelectric coupling factor at the sum frequency ∑f, and the difference frequency ∆f, shown values are mean ± st.d.; *** indicates p < 10e−20; significance was assessed using paired t-test; n = 50 measurements. g Spatial distribution of the measured electric potential VAE at the difference frequency ∆f and sum frequency ∑f and their superposition (normalized to max value) in the radial plane \(\hat{x}\hat{y}\) at different phases θ of the acoustic period (\(1/{f}_{{\rm {A}}}\)).
