Study on dielectric properties of SD rat tissues in vitro

Dielectric behavior of organism is the main topic on biodielectrics. In the present work, we perform the systematic dielectric frequency spectroscopy study on different tissues of SD rat. In our dielectric measurements, we used two Au-coating Cu plates as cathode and anode, which are connected to an impedance analyzer to measure the dielectric frequency spectra (f= 42Hz~5MHz) of the following tissues of SD rat: liver, heart, kidney, abdominal muscle, skeletal muscle and lung. The result shows that although the dielectric parameters vary in value, the frequency-dependent tendencies show the same dielectric-relaxation behavior: a) ε´ gradually decreases with increasing frequency; b) loss tangent (tan δ) shows a peak with the increase of frequency. Furthermore, the influence of temperature and time in vitro on the dielectric behavior of tissues have been measured and discussed. Our results shows that for the same tissue, as the elongation of time in vitro (0~24h), ε´ increases in the low frequency band (f=42~1KHz) and high frequency band (above 1M Hz), but it decreases in the mid frequency band (f=10 ~10 Hz). Meanwhile the peak of loss tangent is in a rising tendency and its shifts to the higher frequency. On the other hand, on rising the measuring temperature of the same tissue from 15C~45°C, the magnitude of the peak of dissipation factor increases. Our result can provide important reference for the impact of electromagnetic wave on organisms.