Reviewed by Lexie CornerJul 9 2024
Researchers from the Nanyang Technological University Singapore have created a plaster or “band-aid” that measures bodily “biomarkers,” which can reveal health or illness. This discovery, published in the journal Analytical Chemistry, opens the door to a new, noninvasive method for patients to track their well-being.
The smart plaster developed by NTU Singapore researchers comprises microlaser sensors embedded in liquid crystal droplets. The sensors are customized to pick up three different types of biomarkers (lactate, glucose, and urea). A different colored liquid crystal dot on the plaster distinguishes each biomarker. Image Credit: Nanyang Technological University
According to a team of NTU researchers from the School of Electrical and Electronic Engineering (EEE), human perspiration contains biomarkers like glucose, lactate, and urea that signal various health issues. It can also be collected in a noninvasive and painless manner, making it perfect for daily monitoring.
People with diabetes commonly use an invasive finger prick test to track their blood glucose levels. To get a reading from a portable glucose meter, patients must prick their fingertips to collect a tiny drop of blood on a strip. Sensor-based monitoring systems are an alternative; however, they require lengthy skin attachments to the patient and are costly and inflexible.
The NTU team's tiny and flexible light-based sensing device, which resembles a plaster, could obtain a very accurate biomarker reading in minutes. The device was constructed by encasing a microlaser in liquid crystal droplets and embedding the liquid within a soft hydrogel sheet.
Our innovation represents a non-invasive, quick, and effective way for diabetic patients to monitor their health. By combining a microlaser with a soft hydrogel film, we have demonstrated the feasibility of a wearable laser to provide a more pleasant health monitoring experience for patients.
Chen Yu-Cheng, Assistant Professor and Director, Centre for Biodevices and Bioinformatics, Nanyang Technological University
According to the NTU research team, their invention advances healthcare in Singapore and worldwide. In Singapore, over 400,000 Singaporeans live with the disease, and this number is projected to exceed one million by 2050.
The research fits in with the University's research pillar of NTU 2025, a five-year strategy plan that attempts to use cutting-edge research to improve public health and society.
Detecting Multiple Biomarkers
The NTU team embedded Liquid crystal droplets with microlasers to build their plaster gadget. Thanks to their customization, the microlasers can detect three distinct kinds of biomarkers (urea, lactate, and glucose). Each biomarker is identified by a different-colored liquid crystal dot on the plaster.
The quantity of light the microlasers emit when sweat interacts with the plaster varies according to the concentration of biomarkers. Users shine a light source on the plaster to detect the biomarker levels, and a smartphone application analyzes and translates the light released by the microlaser sensors.
In actual tests, the plaster detected minuscule variations in sweat's glucose, lactate, and urea levels down to 0.001 mm, which is 100 times more accurate than comparable existing technology.
The NTU team thinks their invention is the first publicly released wearable sensing tool that can measure several biomarkers in sweat with extremely high sensitivity and dynamic range. According to the scientists, the sensitivity allows for tracking a dynamic range (low to high) in biomarker levels, which offers detailed information on patients' health.
Our device is capable of detecting both the high and low range of biomarkers levels. This is particularly beneficial for diabetic patients as current similar health monitoring devices focus on tracking only high glucose levels but not abnormal or low glucose levels, which may indicate other health complications. In comparison, our device will provide a clearer picture of the users’ health condition with a variety of readings captured.
Nie Ningyuan, Study First Author and Ph.D. Candidate, Nanyang Technological University
Commenting as an independent expert, Dr. Lin Chun-Hsien, MD, Physician at National Taiwan University Hospital, Taiwan, said: “Diabetic patients need to frequently monitor their blood glucose level for their safety, for example, to avoid hypoglycemia, which is a condition where blood sugar level drops too low. As an endocrinologist, I often come across patients who fear pain and bleeding when using the finger prick test.”
I am hopeful 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. Its ability to measure other biomarkers is also an added bonus, which will offer more health data to the benefit of both patients and physicians.
Dr. Lin Chun-Hsien, MD, Physician, National Taiwan University Hospital
The study team's next objectives involve optimizing the microlaser sensors to identify a greater range of materials, such as medications and other compounds present in sweat.
This smart 'band-aid' could help monitor your health without pricking your fingers
Video Credit: Nanyang Technological University
Journal Reference:
Nie, N., et al. (2024) A Wearable Thin-Film Hydrogel Laser for Functional Sensing on Skin. Analytical Chemistry. doi.org/10.1021/acs.analchem.4c00979.