Color-Changing Tattoos May Be the Future of Health Monitoring

By Dani Lewis

Imagine a world where you could design a personalized health tracking device that stays with you…forever.

A special kind of tattoo has been developed to help patients monitor fluctuating levels of glucose, albumin, or pH in their bodies. This color-changing tattoo requires a shallow injection into the dermis, located between the epidermis and hypodermis layers of the skin. The research was completed by Ali Yetisen and his team at The Technical University of Munich. Yetisen’s team chose these three biomarkers because they serve as indicators for a range of health problems, according to their research paper “Dermal Tattoo Biosensors for Colorimetric Metabolite Detection” in Angewandte Chemie International Edition.

A Collision of Art and Science

“A functional cosmetic technology was developed by combining tattoo artistry and colorimetric biosensors,” Yetisen and his team explained in their research. Each dye they created responds to a specific variable in the blood and changes color accordingly.

One of the dyes reacts to pH and gradually changes from yellow to blue, depending on the blood’s acidity level. Another dye acts as a glucose sensor and shifts from light green to dark green, which could help people manage their diabetes. The third dye reads levels of albumin and morphs between shades of blue, providing potential aid for people at risk of liver or kidney failure.

Color Changing, Life Saving

These chameleon-like tattoos have already been able to identify changes to key health markers in animals, which creates a promising future for monitoring chronic health conditions in humans.

The researchers also tested whether an app, accessed on a smartphone, would be capable of analyzing tattoo colors to gauge blood pH, glucose, or albumin levels. The app requires the user to take a photo of their tattoo with their phone’s camera before it would be able to analyze the tattoo’s color. Specific calibrations play a part in the app’s ability to evaluate the shade, brightness, and saturation of the tattoo.

“If it works as well on a real human body as it does in the test system with pieces of pig skin, it could allow people to integrate blood biomarker levels with other digital heath data that they already collect with their smartphones,” said Eva Amsen in the Forbes article “Are Color-Changing Tattoos The Future Of Health Monitoring?”

Current Implications and Future Applications

One challenge that researchers are determined to overcome is making the ink color changes reversible. The pH-sensing ink stands alone as the only dye able to return to its original color. The dyes developed to detect glucose and albumin are only able to change one time and cannot return to their original color, even if the respective biomarkers revert to their original levels. This issue will need to be addressed before the technology can be broadly introduced and expanded to wider functions.

“The applications of the sensors can be extended to the detection of electrolytes, proteins, pathogenic microorganisms, gases, and dehydration status,” Yetisen’s team told News Medical Life Science in “New color-changing tattoos can monitor glucose levels and other metabolites in real-time” by Lois Zoppi.

These metamorphic tattoos have yet to be tested on humans, so you’ll have to wait a little longer to monitor your health with a personally designed, life-long wearable.