Creams and Oils: Possible THz Coupling Media for Rough Surfaces?

Ex vivo and in vivo studies of human skin using reflected terahertz radiation (THz) have revealed that THz has potential for use in medical diagnosis of skin diseases. Detected signals could be enhanced via the application of creams or oils. This idea is similar to that in therapeutic ultrasound: hydrophilic gels improve the coupling of the acoustic wave to the stratum corneum (SC). The use of creams or oils to enhance THz coupling to the SC has not been previously explored. This paper elucidates the impact of two types of commercially available ointment on three different pseudo-skin phantoms at THz frequencies.