Digital holographic interferometry for the measurement of temperature distribution around textile conductive yarn embedded in heating garments

Due to the development of wearable smart/electronic integrated textiles, the heating compression bandages, conductive fabrics, and electrically heated garments have been extensively used in many fields. Heating garments could be widely applied in the field of body warming and physical therapy. To impart heating therapy through garments, we need to select conductive yarn to be incorporated into the fabric. In addition to this, voltage supply, resistance, temperature distribution, temperature gradient, heating area, and spacing between the two consecutive conductive yarns are some major factors that have to be optimized for heating garments. Therefore, identifying the proper conductive yarn and approximate spacing between them is important in the electrically heated garments. The measurement of temperature and temperature profile around heated textile conductive yarn is demonstrated using digital holographic interferometry (DHI). DHI has been widely used to measure temperature and temperature profile of gaseous flames and heat conduction studies, etc., as it is more accurate, precise, and provides better spatial resolution. DHI is chosen to measure temperature distribution around copper and stainless-steel yarns used in textiles. DHI is a noncontact, noninvasive, full-field, and almost real-time interferometric technique. We have chosen copper and stainless-steel yarn to study the temperature profile and uniform heating to approximate spacing between two yarns.