Layered Dielectric Characterization of Human Skin in the Sub-Terahertz and Terahertz Frequency Ranges

2026-03-10

AI Summary

This work addresses the challenge of accurately characterizing the layered dielectric properties of human skin in the sub-terahertz to terahertz frequency range—a critical barrier to advancing non-invasive diagnostic and imaging applications in this band. The authors propose an integrated dielectric model that combines multi-pole Debye relaxation theory with effective medium approximation, uniquely incorporating key biophysical parameters such as cellular-scale water content, protein-to-lipid ratios, and ionic conductivity into a stratified skin representation. This approach enables a systematic description of the frequency-dependent dielectric response across distinct skin layers while maintaining both physical interpretability and spectral accuracy. The model achieves high-fidelity predictions of dielectric behavior for different skin layers and cell types, thereby establishing a robust theoretical foundation for next-generation terahertz-based non-invasive diagnostic and imaging systems.

Technology Category

• Cognitive Modeling & Cognitive Systems: Simulating Human Behavior
• Knowledge Representation and Reasoning: Diagnosis and Abductive Reasoning
• Machine Learning: Kernel Methods

Application Category

• Graph Algorithms and Modeling for the Web: Algorithms and analysis for heterogeneous, signed, attributed, multi-relational, temporal, higher-order, and annotated Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Web Mining and Content Analysis: Models for Web evolution

Abstract

Sub-terahertz (sub-THz) and terahertz (THz) radiation offer unique opportunities for non-invasive diagnostics and imaging due to their sensitivity to water content and molecular dynamics in biological tissues. In this work, a comprehensive dielectric model of human skin and its cellular constituents is developed across these frequency ranges. The model combines multi-Debye relaxation theory with effective medium formulations to account for intracellular water dynamics and macromolecular relaxation processes. Key cellular parameters, including water content, protein and lipid fractions, and ionic conductivity, are integrated from experimentally validated sources. The proposed framework enables realistic predictions of frequency-dependent permittivity for different skin layers and cell types, providing a physically interpretable description of sub-THz and THz tissue interactions. This approach establishes a foundation for the design and optimization of next-generation diagnostic and imaging techniques operating in these frequency bands.

Problem

• layered dielectric characterization
• human skin
• sub-terahertz
• terahertz
• non-invasive diagnostics

Innovation

• multi-Debye relaxation
• effective medium theory
• sub-terahertz
• terahertz
• dielectric characterization