Development of a New Sportswear with a Pattern That Changes in Response to Lactic Acid in Sweat

Abstract

In this study, we succeeded in compositing fabrics and lactate-responsive polymers with various patterns developed by the principal investigator with the hope of creating sportswear with a pattern that changes in accordance with the concentration of lactic acid in sweat. First of all, we composited the polymers with the fabrics by the following steps: impregnating a cotton cloth with a monomer solution and polymerizing it by UV irradiation through a photomask with a predetermined shape of light-transmitting area. Then, after coloring the obtained samples with an anionic dye and immersing it in a lactic acid solution, we observed the pattern on the cloth changing with desorption of the dye in response to lactic acid. Additionally, we examined the dependence of the response on the concentration of lactic acid and its change over time and it was found that the pattern changed from a "smiling face" to a "crying face" within 30 minutes within the concentration range of lactic acid present in sweat.