Scientists at Nanyang Technological University in Singapore (NTU Singapore) have developed a “Band-Aid” or adhesive tape that measures internal “biomarkers” that indicate health or disease through sweat, paving the way for new non-invasive and effective ways for patients to monitor their health.
Human sweat contains biomarkers such as glucose, lactate and urea that indicate a range of health conditions and can be collected non-invasively and painlessly, making it ideal for routine monitoring, said the research team from NTU’s School of Electrical and Electronics Engineering (EEE).
People with diabetes typically self-monitor their blood glucose levels with invasive finger-stick tests: patients prick their finger to collect a small amount of blood on a strip that is then inserted into a portable glucose meter for measurement. The alternative is sensor-based monitoring devices, but they are expensive, rigid and must be worn on the patient’s skin for extended periods of time.
By encapsulating microlasers in liquid crystal droplets and embedding the liquid within a soft hydrogel film, the NTU team has created a compact, flexible, light-based sensing device, like a bandage, that can provide highly accurate biomarker readings within minutes.
“Our innovation represents a non-invasive, rapid and effective way for diabetic patients to monitor their health. By combining the microlaser with a soft hydrogel film, we have demonstrated the feasibility of a wearable laser to provide a more comfortable health monitoring experience for patients,” said Chen Yu-Cheng, assistant professor in NTU’s School of EEE and director of the Center for Biodevices and Bioinformatics.
The NTU research team said their innovation will support healthcare in Singapore and globally, where diabetes prevalence is on the rise – more than 400,000 Singaporeans are living with diabetes, a number predicted to exceed one million by 2050.
The innovation was reported in the journal Analytical ChemistryThis is in line with the university’s research pillar, NTU 2025, a five-year strategic plan that aims to leverage innovative research to contribute to society and human health.
Multiple biomarker detection
The NTU team created the plaster device by embedding a microlaser in a liquid crystal droplet, which was customised to detect three different biomarkers – lactate, glucose and urea – with different coloured liquid crystal dots on the plaster distinguishing each biomarker.
When sweat reacts with the bandage, the amount of light emitted by the microlaser varies depending on the concentration of biomarkers present. To read the levels of biomarkers, the user holds a light source over the bandage and the light emitted by the microlaser sensor is analyzed and translated by the mobile application.
In actual tests, the bandage successfully detected fluctuations in glucose, lactate, and urea levels in sweat down to 0.001 millimeters (mm), 100 times more accurate than similar current technologies.
The NTU team believes their innovation is the first wearable sensing device that can measure multiple biomarkers in sweat with ultra-high sensitivity and dynamic range. This sensitivity allows them to track the dynamic range (low to high) of biomarker levels, providing comprehensive information about a patient’s health, the team said.
“Our device can detect both high and low ranges of biomarker levels, which is especially beneficial for people with diabetes, as similar health monitoring devices currently in use focus on tracking only high blood glucose levels, and not abnormal or low blood glucose levels that may indicate other health complications. In comparison, our device can capture a wider range of measurements to give a clearer picture of a user’s health status.”
Nie Ningyuan, a doctoral student at NTU and first author of the study
Lin Chun-Sheng, MD, a physician at National Taiwan University Hospital in Taiwan, commented as an independent expert: “Diabetes patients need to frequently monitor their blood glucose levels to be safe, for example to avoid hypoglycemia, a condition in which blood sugar levels drop too low. As an endocrinologist, I often encounter patients who are afraid of the pain and bleeding associated with performing finger-prick tests. I hope that this laser-based, non-invasive wearable device developed by the NTU Singapore team can provide a more convenient and effective way to monitor patients’ blood glucose levels. The ability to measure other biomarkers is also an added bonus, providing more health data to benefit both patients and doctors.”
As a next step, the team plans to fine-tune the micro-laser sensor so that it can detect a wider variety of substances in sweat, including drugs and other chemicals.
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Nanyang Technological University, Singapore
