Table 5.

Global trends for optical tissue phantoms development using 3D printing

Category	Trend
Methods	Spin coating process predominates because this technique allows thin layers to be generated (30–60 μm in thickness), which better mimic the layer structure of biological tissues
Materials	Polydopamine, polydimethylsiloxane, and the hydrogel, PVA, are present to elaborate matrix tissue phantoms. To mimic scattering properties, TiO2 powders, intralipids, and PVA (involving a freeze-thaw treatment) are used. Finally, those applied to mimic absorption properties include India ink, dyes, graphite powder, hemoglobin solutions, and coffee
Uses	Applications are divided into the following:  Diagnosis techniques, specifically: (1) Medical imaging procedures: confocal microscopy, optical coherence tomography, optical diffusion tomography, hyperspectral reflectance imaging, fluorescence imaging and photoacoustic; and (2) spectroscopy (diffuse reflectance and near-infrared spectroscopy); and Phototherapy techniques, especially in tests for tattoo removal using laser

PVA: Polyvinyl alcohol, 3D: Three-dimensional