Does human skin truly behave as an array of helical antennae in the millimeter and terahertz wave ranges?

The sweat ducts of the human perspiration system are helically shaped tubes, filled with a conductive aqueous solution. Recent studies have claimed that these ducts act as an array of low-Q helical antennae and are dominant in shaping the spectral response in the subterahertz region. Using local homogenization theory for the skin embedded with sweat ducts, we found that multiple interference effects from the skin layers play the major role in determining the skin electromagnetic characteristics in the millimeter and terahertz regions without the need for the assumption of the sweat ducts acting as low-Q helical antennae. (C) 2010 Optical Society of America