Using antibacterial fibers and metallic wires to make woven fabrics used as smart diapers

Abstract

Cloth diapers also known as eco-diapers, traditional sandwich-structured eco-diapers are composed of top and bottom layers that are made of cotton or polyester nonwoven fabrics. On account of the hydrophilic bottom layer, urine permeates when the water absorption reaches saturation. In this study, polypropylene is melt-blown into hydrophobic polypropylene nonwoven fabrics to be used as the top and bottom layer. Polypropylene is hydrophobic but after being fabricated into nonwoven fabrics, the porous structure enables the urine to leak to the absorbent interlayer of eco-diapers. Hence, the top layer of diaper does not contain urine, which makes smart diapers more comfortable than cloth diapers that are made of cotton or other moisture-absorbent materials. Moreover, the sensing mechanism via Bluetooth module can detect the water content of the interlayer with a view to improving the demerit of urine leakage. The interlayer is the sensing layer that has antibacterial function. Two types of antibacterial yarns are treated by zinc oxide and silver ions. The yarns are fabricated into antibacterial woven fabrics, after which the antibacterial properties of fabrics are investigated with quantitative and qualitative tests. Next, two parallel metallic wires are assembled in order to trigger short circuit when sensing moisture, thereby obtaining different electric resistance based on different moisture levels. Furthermore, the miniature senor can signify the cellular phones or buzzers when the two metallic wires generate electrical resistance due to the presence of urine. The metallic wires are silver-plated copper yarns, stainless steel fibers, and copper fibers, which possess different electric resistance for the corresponding miniature sensors. This study proposes an efficient manufacture of smart diapers that require only a combination of woven fabrics and two metallic wires to sense moisture, the design of which can be encompassed in diverse fields.