Human sweat ducts as helical antenna: Prospects for practical applications

以往的研究表明，太赫兹（THz）波与人体皮肤之间的相互作用发生在一个特定的频率，由于在皮肤表皮的螺旋结构的汗管的存在。当汗管充满汗液时，它充当低Q螺旋天线，并且导管的频率由皮肤和汗液的形态特征（例如汗管的直径）和介电特性两者决定。为了进一步研究这一点，我们测量了从人体各个部位收集的汗液的折射率和吸收系数。此外，我们设计了一个低成本的太赫兹波四分之一波片，使我们能够研究偏振相关的皮肤太赫兹反射。

Previous studies have indicated that the interaction between terahertz (THz) waves and human skin occurs at a specific frequency due to the presence of a helical structure sweat duct in the epidermis of skin. When the sweat duct is filled with sweat, it acts as a low Q helical antenna, and the frequency of the duct is determined by both the morphological characteristics (such as the diameter of the sweat duct) and the dielectric properties of the skin and sweat. To investigate this further, we measured both the refractive index and absorption coefficient of sweat collected from various parts of the human body. Additionally, we designed a low-cost terahertz wave quarter wave plate that allows us to study the polarization-dependent terahertz reflection of the skin.