Technical background When the human body is worn and used, the skin will be contaminated with oil, sweat and other metabolites excreted by the skin. These stains are difficult to detect by the naked eye, but provide important nutrients for the growth and reproduction of pathogens. The self-perceived cleanliness function of textiles, through the recombination of natural extracts and textiles, causes the stains such as oils, sweats and bacterial metabolites contaminated on textiles to accumulate to a certain amount and produce color changes, thus reminding us to clean in time. To the maximum extent, the long-term accumulation of stains leads to the proliferation of germs, which in turn affects people's health. Technical principle Smart-Echo Tech combines pure natural extracts to give cotton fabrics a self-perceived cleanliness function: “stained discoloration, decontamination and recovery”. When a certain amount of pollution sources (such as oil, sweat, and fine metabolites) are contaminated with eco-sensitive fabrics, the molecular structure of the fiber surface will re-conform, which will trigger the color change of the fabric, which will be restored after daily washing or soaping. Textiles made with this technology can always remind people whether they are contaminated and need to be cleaned at all times.