Simulation of a Photoacoustic-Based Gold Authentication System for Tungsten Inclusion Detection Using COMSOL Multiphysics

The increasing presence of counterfeit gold, especially with tungsten inclusions, poses a significant challenge to the authenticity of gold trading. This research presents a photoacoustic sensing (PAS) method for detecting tungsten inclusions in gold bars. Photoacoustic sensing leverages laser-induced acoustic waves to identify material discrepancies based on their thermal and optical characteristics. This approach enhances the detection capabilities by focusing on the photoacoustic response generated by the interaction of the gold and tungsten matrix with laser light, making it a more reliable and efficient non-destructive testing method. The proposed method is modelled and simulated using COMSOL Multiphysics, providing a simulation-based solution for gold verification. This research aims to contribute to the promotion of fair-trade practices by ensuring the authenticity of gold, aligning with the Sustainable Development Goals (SDGs), specifically SDG 8: Decent Work and Economic Growth, and SDG 12: Responsible Consumption and Production.