Weaving Wellness Into Your Life

In recent years, the healthcare industry has witnessed a significant surge in the development and utilization of wearable medical devices. These devices have garnered immense attention due to their potential to provide continuous monitoring of various health parameters. Among the diverse array of wearable devices, sweat sensors have emerged as a particularly promising avenue for monitoring numerous health conditions. These sensors have the capability to noninvasively track various biomarkers present in sweat, offering a comprehensive understanding of an individual's health status.

One of the key reasons for the burgeoning interest in sweat sensors is their ability to monitor crucial biomarkers such as pH levels, glucose levels, and electrolyte concentrations. By continually tracking these vital indicators, healthcare professionals can gain valuable insights into an individual's health, enabling them to make more informed decisions about treatments. For instance, sweat sensors can play a pivotal role in monitoring glucose levels in individuals with diabetes, allowing for timely adjustments to insulin dosages and dietary plans. Similarly, they can aid in the assessment of electrolyte imbalances, which are particularly relevant for patients with conditions such as dehydration, kidney disorders, or cardiac issues.

The most important aspect of these sensors is, of course, that they can continually monitor important biomarkers. But for that to be practical in the real-world, these sensors must be effortless to use, comfortable to wear, and socially acceptable. A number of wearable sweat sensors have been developed in the past, but they tend to ignore these factors. Researchers at the Hybrid Body Lab of Cornell University set out to correct that problem with their innovation that they call BioWeave. BioWeave is a woven textile-based sweat sensor that can be transparently incorporated into clothing while it measures the presence of biomarkers.

The developers focused on two sensing modalities with BioWeave — colorimetric and electrochemical. Colorimetric sensors are designed to visibly alter their color when they come into contact with a target analyte. Electrochemical sweat sensors, on the other hand, apply a current between a pair of electrodes. When an ion-selective membrane is applied to one of the electrodes, this setup can be used to measure the concentration of a specific biomarker. Both options are reusable. After either the sweat evaporates, or the fabric is washed, the sensor will return to its original state and be ready for reuse.

To produce the colorimetric threads, natural fibers were chosen as the base due to their natural ability to wick liquids and to be dyed in an obvious fashion. The sensing capability was added by soaking commercial colorimetric test strips in deionized water to remove the active component, then using that solution to dye the fiber. Four types of electrochemical sensing threads were produced to detect the presence of glucose and pH levels. In these cases, solutions containing materials like carbon, silver, and chitosan were produced, then used to build up layers on the sensing threads. After this process was complete, the threads could serve as electrodes with a specificity for a particular biomarker of interest.

Using their methods, the team created a number of fabric patches, and demonstrated how they could be used in a number of body locations, like under the eye, under the arm, on the chest, or between the toes. A small user study showed that these wearable sensors were comfortable to use, but the team noted that while their fabrication approach is highly accessible, reliance on off-the-shelf commercial test strips for the colorimetric sensors limits the number of biomarkers that can be tested, and the concentration ranges that can be detected. But with the accomplishments achieved by the team, they have hope that BioWeave will lower the barrier for sweat-based chemical sensing.