Small Device, Big Impact: Wearable Sensor Monitors Health from Sweat

A team of Caltech researchers has developed a new wearable sensor that can detect even minute levels of many common nutrients and biological compounds in human sweat. This could revolutionize the way we monitor our health, making it easier and more convenient to track our nutrition, hydration, and overall well-being.

The sensor uses molecularly imprinted polymers, which are like artificial, reusable antibodies. These polymers have tiny holes that are shaped specifically to fit certain molecules, such as amino acids or vitamins. When sweat containing these molecules comes into contact with the sensor, the molecules bind to the holes, reducing the flow of electricity and creating a measurable signal.

The sensor also uses microfluidics, which allows it to operate with very small amounts of sweat. This is important because sweat production can be stimulated electrically, but it requires a small amount of current. The microfluidic design allows the sensor to use even less current, making it more comfortable for users.

The researchers have successfully tested the sensor on human subjects in laboratory settings. They are now planning to conduct larger-scale human trials to evaluate its accuracy and effectiveness.

"This approach allows us to detect a bunch of new crucial nutrients and metabolites," said Wei Gao, assistant professor of medical engineering and lead author of the study. "We can monitor when we eat and watch nutrient levels change. It not only monitors nutrients, but also hormones and drugs. It can provide continuous monitoring for many health conditions."

The researchers believe that their sensor could have a wide range of applications, including:

• Nutritional monitoring: The sensor could be used to track nutrient levels in real time, helping people to make sure they are getting the right balance of nutrients.
• Hydration monitoring: The sensor could be used to measure sweat loss, which is a key indicator of dehydration.
• Stress monitoring: Cortisol, a stress hormone, is excreted in sweat, so the sensor could be used to monitor stress levels.
• Drug monitoring: The sensor could be used to monitor the release of drugs from transdermal patches.

The development of this sensor is a significant step forward in the field of wearable sensors. It has the potential to revolutionize the way we monitor our health and improve our overall well-being.