Tissue phantom to mimic the dielectric properties of human muscle within 20 Hz and 100 kHz for biopotential sensing applications

Tissue-mimicking materials for phantoms are fabricated for research purposes to simulate the mechanical or electrical properties of real human tissues and promote better understanding of their properties. This research investigated the dielectric properties (from 20 Hz to 100 kHz) of five promising muscle mimicking materials including matrix materials (gelatin powder and agar powder), and fillers (sodium chloride, glycine and aluminum powder) for the development of muscle phantoms. The mechanical behaviors were verified as well. This research determined the effects of electrode polarization (EP) on the dielectric properties of each material and then used a mathematical model to reduce these unwanted effects. Additionally, the results indicated the very low dielectric properties of gels-only samples. Both electrical conductivity and relative permittivity increased with increasing concentrations of fillers. Moreover, all fillers had their own capabilities to alter the levels and trends in the increments of dielectric values, which provide a wider selection to muscle-mimicking materials. Theoretically, it is feasible to achieve desired dielectric properties by mixing these fillers together with certain ratios. In this way, low-cost muscle phantoms can be produced and used as experimental subjects for biopotential sensing application.