Human Skin Models in Biophotonics: Materials, Methods, and Applications

Human skin shows complex optical properties that influence how light is absorbed, scattered, and reflected, playing a key role in biophotonic applications such as diagnostics, imaging, and therapy. Replicating these characteristics in vitro is essential for developing realistic optical skin models that reduce reliance on animal testing and provide standardized platforms for research and product development. This review presents the fundamental optical properties of human skin and outlines the principles and materials used to replicate these properties, including absorbers, scatterers, and matrix materials. Strategies for fabricating optical skin models are discussed, with models categorized according to their structural complexity and functional capabilities. Finally, it explores the state-of-the-art skin models in studying light-skin interaction and their applications, including optical models that incorporate other physical properties and biological components. With an increase in the usage of light applications on the skin, these models are expected to support the development of personalized biophotonic tools and provide platforms for studying light-skin interactions under controlled and reproducible conditions.