As summer temperatures soar in Texas and other hot regions, staying hydrated becomes more important than ever.
But it’s often hard to know when you’re running low on fluids—until you feel dizzy, tired, or get a headache.
A team of researchers at The University of Texas at Austin is tackling this problem with a new wearable device that can monitor hydration levels continuously and noninvasively, giving people a simple way to track their water needs in real time.
Led by Professor Nanshu Lu from the Cockrell School of Engineering, the team created a lightweight, flexible sensor that sits on the skin and uses a method called bioimpedance to measure hydration.
This technique works by sending a very small, safe electrical current through the arm.
Because water conducts electricity well, the sensor can detect how hydrated your body is based on how easily the current flows. The drier your tissues are, the more they resist the current.
All of this data is sent wirelessly to a smartphone, allowing users to see their hydration status throughout the day—whether they’re working out, walking around, or just sitting at a desk.
The findings were published in the Proceedings of the National Academy of Sciences.
“Dehydration is a silent problem that can affect anyone,” said Lu. “This sensor gives people a tool to monitor themselves, stay healthy, and perform better—whether they’re athletes, firefighters, or office workers.”
To test how well the device works, researchers carried out several studies. In one experiment, volunteers took a diuretic (a medication that causes water loss), and the team compared the sensor’s readings with urine samples and body weight changes.
They found that the sensor closely tracked hydration levels and matched standard tests.
Co-author Matija Jankovic explained that the device can monitor body hydration accurately even during normal daily activities. This makes it much more practical than traditional hydration tests, which often require urine or blood samples and aren’t useful outside of clinical settings.
Hydration is critical for everything from brain function to temperature control to preventing serious health problems like kidney stones and heatstroke. Yet many people don’t drink enough water during the day, especially in hot environments or while being active.
This new sensor could be especially helpful for workers in extreme conditions, athletes, or people managing health conditions like kidney or heart disease. In the future, the researchers hope to develop even more comfortable versions—such as breathable electronic tattoos—and expand their testing to other body parts like the forearm or thigh.
The team’s next goal is to develop a database of normal hydration levels so the device can provide absolute values, not just trends. But even in its current form, the sensor brings us one step closer to making real-time hydration tracking available for everyone.
