Researchers at the University of Hawaii at Manoa have developed a wearable that can take multiple sweat samples and which also supports on-board colorimetric biomarker analysis. Unlike many sweat collecting methods, which often involve a simple absorbent pad that must be removed and analyzed once wet with sweat, the ‘sweatainer’ employs a complex microfluidic architecture to take multiple sweat samples over time and store them in different compartments for later analysis. 3D printing was the key to creating this more sophisticated sweat analysis wearable, allowing the researchers to create tiny microfluidic channels and reservoirs within the device.
Sweat analysis provides a unique window into our physiology and has major advantages in terms of non-invasive sampling, with the potential to cast light on a range of serious health conditions including diabetes and heart failure, and also routine issues that can affect anyone such as dehydration and fatigue. An array of wearables has been created in recent years that are intended to collect sweat for later analysis.
However, many such devices have limitations. For instance, common approaches involve an absorbent pad that lies on the skin surface, or tiny channels that draw liquid into a single reservoir. Typically, these approaches only allow for one sweat collection, and removing and processing a pad for analysis could contaminate it, along with the requirement for trained lab personnel and sophisticated equipment to perform the analysis.
In contrast, this latest technology allows for multiple sweat samples to be collected over time and stored separately, potentially allowing clinicians to assess changes in particular sweat biomarkers over time. Moreover, the device also supports the inclusion of on-board analysis, completely side-stepping the requirement for an advanced lab for analysis. This could take the form of simple color change tests as a yes/no analysis for the presence of a given biomarker.
The key to achieving this sophisticated sampling was the use of 3D printing to create the device, which allowed the researchers to create a complex internal architecture. “3D-printing enables an entirely new design mode for wearable sweat sensors by allowing us to create fluidic networks and features with unprecedented complexity,” said Tyler Ray, a researcher involved in the study. “With the sweatainer, we are utilizing 3D-printing to showcase the vast opportunities this approach enables for accessible, innovative and cost-effective prototyping of advanced wearable sweat devices.”
Study in Science Advances: Skin-interfaced microfluidic systems with spatially engineered 3D fluidics for sweat capture and analysis
Flashbacks: Sweat Sensor Measures Variety of Biochemicals to Help Monitor Exercise, Disease; Sweat Sensor for Non-Invasive Glucose Measurement; Wearable Sweat Sensor Warns of Impending Cytokine Storm; Wearable, Non-Invasive Sensor Measures Glucose in Sweat;