Review of Phantoms for Mimicking the Electrical Properties and Mechanical Strength of Living Tissue

Objectives

Phantoms are increasingly preferred and essential in research for applications such as imaging device calibration or sensor validation. They offer significant advantages in terms of measurement repeatability and reproducibility, long-term stability, cost effectiveness, ease of storage, and the absence of ethical concerns. This review aims to analyse the materials and fabrication techniques used to develop phantoms that replicate the electrical properties of human tissues while ensuring comparable mechanical strength.

Materials and Methods

To establish relevant design criteria and define the requirements for phantom fabrication, a preliminary review of the electrical and mechanical properties of biological tissues was conducted, along with an analysis of measurement techniques such as bioimpedance. A comprehensive review of the literature was then performed to assess various phantom materials, including intrinsically biomimetic materials, natural and synthetic polymers, with a focus on their electrical and mechanical properties, long-term stability, and environmental impact. Additionally, the review considered whether the phantoms were anthropomorphic, designed to closely mimic human anatomy, or simplified, depending on the experimental requirements.

Results

Biological materials, including vegetables and animal flesh, possess electrical properties that approximate those of human tissues but are limited by issues such as rapid degradation over time and potential ethical concerns. Natural polymers, such as gelling agents, are easy to use, however, they require stabilisers and fillers to enhance stability and electrical properties. These polymers exhibit reduce mechanical strength in comparison to living tissues. Synthetic materials, including silicones and elastomers, offer superior mechanical strength but require fillers to mimic electrical properties. Among these, polyvinyl alcohol (PVA) stands out as an environmentally friendly alternative.

Conclusion

The selection of materials for phantom fabrication involves a trade-off between mechanical performance, electrical properties and environmental considerations. Advances in sustainable materials offer promising directions for improving phantom design.