Over the past two years, the wearable devices segment, such as Smart watch and fitness trackers, it seems the adoption of new biosensor capabilities has stalled. Yes, engineering in its miniature form is not easy, but at the same time, we are seeing amazing advances in wearables.
The latest information comes from experts at Nanyang Technological University in Singapore. The team has developed a bandage-like patch that can analyze sweat and find biomarkers. In the field of microfluidics, sweat is seen as a gold mine of health data and the next big thing for wearable technology.
In a research paper published in the journal Analytical Chemistry, the team describes a hydrogel-based film with separate chemical reservoirs to measure lactate, urea, and glucose levels in sweat. The method is completely non-invasive, meaning all data is analyzed from sweat that appears on the skin after any form of exercise.
The patch contains a small laser, which is the heart of the sensor. This assembly is covered with small droplets of liquid crystal, which help control the laser. These laser-filled beads are placed in a soft, jelly-like material called hydrogel, which makes the patch flexible and comfortable to wear.
The team claims that this is the first wearable sensor of its kind that can detect and measure various chemicals in sweat with incredible accuracy. What makes it special is that it can detect a wide range of these chemicals, from very small amounts to much higher concentrations.
When applied to the skin, it uses laser light to detect and measure certain chemicals or substances in the body. The biomarkers in this case are urea, glucose, and lactate. The best part is that this patch can provide test results in just a few minutes, eliminating the need for users to visit a clinic or deal with cumbersome machines.
Here’s the best part. You just need to shine a light on the patch and your smartphone will do the analysis. The team used an app that reads the light fluctuations and interprets them. “In real-world experiments, the patch successfully detected small fluctuations in glucose, lactate, and urea in sweat down to 0.001 millimeters (mm), which is 100 times better than current similar technology,” the scientists say.
“Our innovation provides a non-invasive, fast and effective way for patients with diabetes to monitor their health. By combining a microlaser with a soft hydrogel film, we have demonstrated the feasibility of using a wearable laser to provide a more enjoyable health monitoring experience for patients,” explains Professor Chen Yu-Cheng from the School of Electrical and Electronic Engineering (EEE) at the institution.
Of the biomarkers mentioned above, glucose is currently a hot target for giants like Apple and Samsung. However, neither company has yet perfected their smartwatch-based glucose testing technology, and it may be some time before we see it on the market. The race is close, and deservedly so.
Currently, measuring blood glucose at home requires puncturing your skin and removing a drop for chemical analysis. This is invasive, and not everyone likes it. It also explains why several teams are exploring ways to analyze blood glucose using LEDs, which we see in smartwatch biosensors.
The flexible shell developed by the NTU team is a step in the right direction. It is a disposable and inexpensive solution, and according to the research, “the range of detectable biomolecules can be expanded, such as drugs excreted in sweat, pathological chemicals, and others.”
In the context of smartwatches with similar capabilities, this is more of a stopgap. I asked the team that created the biosensor patch, and they told me that it cannot be integrated into the smartwatch or fitness band form factor. This is mainly due to the detection model used.
“As the developed sensor is currently not reusable, it cannot be connected to smartwatches, especially because the technology is chemical-based. “Wearables are mainly suitable for measuring physical signals such as heartbeat, blood pressure, etc., as they do not require liquid for measurements,” NTU experts told Digital Trends in English.
But whether or not we can integrate this patch with a smartwatch, there’s huge potential here. Why not consider it as a product of sorts? Some brands, like Ultrahuman, already offer skin patches equipped with sensors to monitor health when connected to a phone.
Then there’s the versatility aspect. The smart patch developed by the NTU team can now detect two additional classes of biomolecules: lactate and urea. In addition, by altering the cholesteric liquid crystal (CLC) droplets in the hydrogel film, the patch can detect even more biomolecules.
Take urea, for example. There is a strong correlation between urea levels in sweat and diabetes-related problems, and it also indicates kidney problems. Interestingly, a paper published in the journal Physiological Measurement details an approach to measuring urea levels in sweat using a light sensor, something like a smartwatch.
Next up, we have lactate levels. Analyzing lactate levels can be useful for athletes, as this chemical in sweat is used to measure training intensity and athletic performance. Interestingly, as detailed in this article in Scientific Reports, it is possible to non-invasively and continuously analyze lactate levels in sweat using a special biosensor.
Epidermal and non-invasive electrode patches have also been developed. Many studies confirm that we are on the threshold of a new leap in portable biosensing.
All we need is a brand willing to experiment with a new product category or build on research relevant to their area of smartwatch and band development. And of course, be ethical in doing so, unlike the hell unleashed by the horrific Apple-Masimo lawsuit over patented wearable technology that led to the Apple Watch being banned.
Source: Digital Trends
