A 3D printed human skin phantom made of multifunctional nanocomposites for the assessment of RF treatments effect

The progress of technology and science has enabled new tools for the diagnosis and treatment of diseases based on electromagnetic (EM) fields. Radiofrequency (RF) EM fields also find application in aesthetic medicine treatments, e.g. for the removal of stretch marks and scars. The employment of EM fields in such treatments is regulated by national and supranational legislation, which limit the Specific Absorption Rate (SAR) below 0.4 W/kg and the temperature increase below 1°C. In this paper we propose the design and fabrication of a 3D printed carbon-based phantom, highly customizable, which mimics the thermal and electrical properties of the three layers of the skin and the abdominal muscle to measure the heating induced by electro-medical fields. The phantom was fabricated by means of Fused Deposition Modeling (FDM) 3D printing technique of nanocomposites. The used filaments are made of PLA filled with different concentrations of Graphene Nano-Platelets (GNPs) and Carbon Nanotubes (CNTs), designed to tune the thermal and electrical conductivity of the deposited layers according to the skin and muscle layers properties. Each layer has holes at different depths to allow inserting thermocouples for the measurement of the heating induced by electro-medical fields. The phantom has a cylindrical shape with a diameter of 120mm and a total thickness of 44.25 mm, for a total weight of 577.36 g, so it is compact and handy. This work paves the way to the development of reliable phantoms of human tissues by means of innovative materials for the thorough investigation of the EM fields effect on human bodies.