Smartphone Touchscreens May Soon Monitor Your Hydration Status

Researchers at King Abdullah University of Science and Technology (KAUST) have discovered that the capacitive sensors commonly found in smartphone touchscreens can be used to assess a user’s hydration level. Unlike current wearable hydration monitors, such as sweat-analyzing patches or tattoos, this approach requires no additional devices—just a simple touch of the finger on a smartphone screen. The research team, led by Prof. Tareq Al-Naffouri, developed a machine-learning algorithm that interprets changes in skin capacitance, which decrease as hydration drops, to categorize hydration into five levels. The technology was tested on 45 volunteers: 35 were fasting during Ramadan and 10 were athletes tested before and after intense exercise. The system demonstrated an accuracy of 87% for fasting individuals and 92% for athletes compared to traditional hydration monitoring methods. The researchers aim to integrate this technology into a user-friendly app, enabling real-time, everyday hydration tracking without the need for specialized equipment. The findings were published in the IEEE Sensors Journal.