Figure 3.

(a) Biological material permittivity spectrum over frequency: ε_r and ε_i denote the real and the imaginary part of the permittivity, respectively. Various processes arise as a function of frequency: ionic and dipolar relaxation, atomic and electronic resonances at higher energies. There are two kind of sensing platforms: (a₁) Direct contact and (a₂) Distance measurements. (b) Pulse propagation along dendride 0 of neuron 0 (red line), axon of neuron 100 (gray dashed line), axon of neuron 150 (green line), target neuron soma (black line) and target neuron axon (blue line) [71]; (c) Resonant frequency shift among healthy tissue (step-line), benign tumor (dot) and malignant tissue (straight line); (d) Extinction cross-section spectra for glucose concentration measurements; and (e) transmission spectra for Oxyhemoglobin and Deoxygenated hemoglobin at reference absorption frequencies [72].