Flexible metasurface sensor for real-time sub-terahertz non-invasive imaging of skin conditions

Real-time, portable skin condition imaging systems are of significant importance in consumer health and wellness, routine health screening, and rural healthcare. In this work, we present a metasurface (MS) sensor–based portable system for real-time, non-invasive monitoring of skin conditions. The proposed flexible dual-layer MS sensor is specifically engineered to operate effectively in high-loss skin environments, such as those typical of biological tissues. By leveraging interference theory, the MS sensor exhibits resonance shifts in response to variations in the dielectric properties of skin. The portable sub-terahertz multi-focal lens imaging system detects reflection changes, enabling the visualisation of abnormal skin regions, including those not readily visible to the naked eye. Experimental results demonstrate the system’s ability to distinguish tissues according to their moisture content. This approach offers a promising portable platform for skin health assessment and holds potential for further customisation and miniaturisation toward rapid skin cancer screening applications.