Advances in wearable materials for terahertz antennas: healthcare-focused survey

Current advancement in in terahertz technology (0.1–10 THz) have shown good potential for biomedical applications like early cancer detection, wound examination, ophthalmic measurements, pharmaceutical quality check etc., because of nonionizing characteristics, sensitivity to water molecules, and capability to differentiate among normal and affected tissues. The THz technology with flexible antennas provides great capability in real-time health monitoring and non-invasive biomedical sensing because of wearables, conformity to skin, and non-contacting features. Due to high dielectric losses, and thermal instability of traditional substrates like PET, PI, and PDMS at THz frequencies, the antenna performance is affected. Advanced materials like liquid crystal polymers, doped PDMS composites, biodegradable biopolymers (silk fibroin, cellulose), engineered metamaterials, and high-conductivity conductors such as graphene, CNTs, liquid metals, and nanoparticle inks may mitigate these challenges by providing low-loss characteristics, biocompatibility, flexibility, and sustainability, and providing a scope for next-generation THz healthcare instruments.