Correlating interface pressure with strain-induced electrical resistance changes of smart knitted compression stockings

Flexible strain sensors in textiles are attractive for sensing human body posture changes. Knitted compression garments used in various medical applications can be a suitable choice for such smart applications. However, compression stockings haven’t been scientifically described for such applications. In this study, smart knitted stockings have been engineered using plain, honeycomb, and birdeye structures. Acrylic, lycra, and conductive polyamide coated with silver colloidal particles were used to architect sensors. The stockings were employed to develop a correlation between strain-indued electrical resistance variations with interface pressure between clothing and wearer’s body. Moreover, thermo-physiological comfort and serviceability characterization were carried out to ensure the comfortable wearing of stockings. Decreasing the percentage of Lycra and increasing the percentage of conductive yarn increased the electrical resistance variations with changing body circumference. Increasing the circumference of the fabric increased the pressure exertion phenomenon causing an increase in electrical resistance owing to the yarns being apart from each other. The comfortability of stockings had a parabolic trend, decreasing yarn accumulation enhanced the comfort i.e., air permeability was enhanced due to tuck stitch porosities in honeycomb structures.