Meet the Johns Hopkins students developing SweatSense, a wearable device designed to help people monitor kidney health using sweat |
Three students at Johns Hopkins University have developed SweatSense, a non-invasive device designed to help people monitor kidney-health indicators using sweat instead of relying solely on conventional blood and urine tests. The project, created by electrical and computer engineering students Ryan Chan, Fausto Kang and Jason Konadu, aims to make monitoring more convenient for older adults and people at risk of chronic kidney disease. The prototype uses a chemical reaction and a colour sensor to estimate urea levels in sweat, then displays the readings through a digital dashboard. SweatSense won the university’s 2026 Dean’s Design Award for Electrical and Computer Engineering. However, the device remains under development, and its accuracy needs to be assessed against standard blood tests before it can be relied upon for clinical decisions.
How SweatSense uses sweat to monitor kidney health
The idea behind SweatSense is to make kidney-health monitoring easier to carry out at home, particularly for people who may find frequent medical appointments inconvenient. Chronic kidney disease can develop without obvious symptoms, and people at risk are often advised to undergo regular blood and urine tests to assess kidney function.The students designed SweatSense as a potential screening and monitoring tool that could help users track changes between clinical appointments. The team hopes people could use it weekly or monthly to observe trends and seek medical advice if their readings raise concerns.According to Johns Hopkins University, the prototype is designed to collect a small amount of naturally produced sweat without requiring users to exercise or deliberately induce sweating.
How the device measures urea in sweat
SweatSense uses a test strip that briefly comes into contact with the user’s underarm. The strip collects sweat and triggers a chemical reaction that produces a blue-green colour in response to urea in the sample.Urea is a waste product formed when the body breaks down protein. The kidneys help remove it from the bloodstream, making urea levels relevant to assessments of kidney function. However, sweat urea levels are not directly interchangeable with blood urea measurements.After collecting the sample, the user inserts the strip into the device. A colour sensor measures the change in the strip, while a microcontroller processes the signal. A Python-based dashboard then displays the estimated sweat urea concentration, an estimated blood urea level and corresponding risk categories ranging from normal to high.The dashboard is intended to make the readings easier for users to understand. The estimates, however, are not a substitute for laboratory testing or a medical diagnosis.
The students behind the SweatSense project
SweatSense was developed by Ryan Chan, Fausto Kang and Jason Konadu, who studied electrical and computer engineering at Johns Hopkins University. Their project received the university’s 2026 Dean’s Design Award for Electrical and Computer Engineering and was presented at the Whiting School of Engineering’s Design Day.The team set out to address the inconvenience of repeated testing for people who need to monitor kidney health. Conventional blood and urine tests can require appointments and laboratory facilities, which may pose difficulties for older adults and people with limited mobility.The students drew inspiration from the accessibility of at-home blood pressure monitors. Their goal was to develop a compact system that could provide useful information between medical appointments without requiring a blood sample for every reading.
The engineering challenges behind SweatSense
Developing the prototype involved solving problems with sensor reliability and interference from external light.The team initially struggled to obtain consistent readings from its sensor because of timing limitations in the Arduino system. The students switched to a different sensor with a digital output, which improved reliability.They also found that ambient light could interfere with the colour sensor’s readings. To address this, they designed a custom 3D-printed enclosure with a dedicated slot for the test strip. The enclosure shields the sensor from external light, helping it measure the strip’s colour more consistently.These changes were important because the device relies on detecting colour differences to estimate the concentration of urea in a sweat sample.
Why clinical validation is the next important step
Although SweatSense demonstrates a potential approach to non-invasive monitoring, the prototype has not yet been established as a clinically validated diagnostic device.The Johns Hopkins team identifies comparison with standard blood tests as an important next step. Such testing would help researchers determine how closely the device’s estimates correspond to laboratory measurements and whether its readings are reliable across different users and conditions.Researchers would also need to establish how effectively sweat measurements can be used to track changes in kidney health over time. Until those questions are addressed, SweatSense should be viewed as an experimental monitoring concept rather than a proven way to detect or diagnose kidney disease.
What the students hope to achieve
The team hopes SweatSense could eventually help people at risk of kidney disease monitor relevant indicators between appointments and recognise when they may need further medical assessment.If future testing establishes that the device can provide reliable readings, a portable sweat-based system could make some aspects of monitoring more convenient for people who face barriers to regular testing. For now, its significance lies in the engineering approach and the possibility it offers, rather than in a demonstrated clinical benefit.The next stage of development will determine whether SweatSense can move beyond a student engineering prototype and become a dependable tool for kidney-health monitoring.
