Applications of terahertz wave technology in smart textiles

Abstract

The terahertz radiation bridges the gap between microwave and infrared light, which consists of electromagnetic waves with frequencies ranging from 100 GHz to 1,000 GHz. There are approximately one-half of the total luminosity and most of the photons emitted since the Big Bang fall into the terahertz frequency region. Terahertz spectroscopy and imaging are two important techniques for the applications to textiles, which are described in this chapter. Some terahertz spectroscopy experimental systems were presented, such as timedomain spectroscopy-based terahertz pulsed system and backward-wave oscillator- based continuous-wave terahertz system. Several applications of the terahertz spectroscopy technique were reviewed to textile identification and sensing, such as textile fibers, textile materials, and wool textiles. Terahertz imaging of object behind textile barriers was demonstrated and the images were segmented for target detection. Terahertz imaging applications to textiles were also reviewed, such as measuring textile water content, detecting target behind textile barriers, and testing composites nondestructively.