Non-Invasive Wearable Sweat and Tear-Based Biosensors for Continuous Health Monitoring

Abstract

Over the years, the continuous advancements within the wearable biosensor field have raised public awareness in exploring new strategies for people's personalized point-of-care testing. Biosensors are multifunctional devices that allow people to quantify a range of biological signals through highly sensitive and small-scale sensing platforms, thus providing users convenience when limiting the need for clinical check-ups and laboratory diagnosis. Via dynamic, non-invasive evaluation of biomarkers in bodily fluids, biosensors are able to provide users with a nearly instant numerical result of the targeted biomarker's level (e.g., glucose, chloride) within their body. Here, this paper mainly focuses on exploring the wide range of sweat and tear-based biosensors' applications and methods to some extent. New generations of sweat-based wearable biosensors have been developed to better monitor one's health status by introducing techniques such as microfluidic sweat collection and Iontophoresis sweat induction methods. Additionally, much investment and effort have been put into developing tear-based wearable biosensors. For example, contact lens-based sensors are the most commonly adopted method for tear analysis, providing a minimally invasive detection of biomarkers.