Tufts University School of Engineering has developed special biomaterial-based inks that respond to the chemicals released from the body and surrounding environment by changing colors. This ink can be printed on to the textiles like shoes, face mask, clothes in a complex pattern providing a detailed map of human response or exposure. This biomaterial-based ink can quantify a wide range of biological conditions molecule and even the pathogens over the surface of the body using conventional garments and uniform.

“The use of novel bioactive inks with the very common method of screen printing opens up promising opportunities for the mass-production of soft, wearable fabrics with large numbers of sensors that could be applied to detect a range of conditions,” said Fiorenzo Omenetto, corresponding author and the Frank C. Doble Professor of Engineering at Tufts’ School of Engineering. “The fabrics can end up in uniforms for the workplace, sports clothing, or even on furniture and architectural structures.”

Wearable sensing devices have attracted considerable interest in monitoring human performance and health. Many such devices have been invented incorporating electronics in wearable patches, wristbands, and other configurations that monitor either localized or overall physiological information such as heart rate or blood glucose. The research presented by the Tufts team takes a different, complementary approach — non-electronic, colorimetric detection of a theoretically very large number of analytes using sensing garments that can be distributed to cover very large areas: anything from a patch to the entire body, and beyond.

The inks are formulated for screen printing applications by combining with a thickener (sodium alginate) and a plasticizer (glycerol). The screen printable bio-inks can be used like an ink developed for screen printing, and so can be applied not just to clothing but also to various surfaces such as wood, plastics, and paper to generate patterns ranging from hundreds of microns to tens of meters. While the changes in color presented by the inks can provide a visual cue to the presence or absence of an analyte, the use of camera imaging analysis scanning the garments or other material can gather more precise information on both quantity and high resolution, sub-millimeter mapping.