"Sweatainer": a 3D-printed sweat analysis health monitoring device

Sweat can hold vital information about health, providing clues to hydration, fatigue, blood sugar levels and even serious conditions such as cystic fibrosis, diabetes and heart failure. Researchers at the University of Hawaiʻi at Mānoa College of Engineering have taken a step forward in sweat analysis with an innovative 3D-printed wearable sweat sensor called the “sweatainer”.

Harnessing the power of additive manufacturing (3D printing), the researchers developed a wearable sweat sensor that expands the capability of wearable sweat devices. The sweatainer is a small, wearable device similar in size to a child’s sticker that collects and analyses sweat. By incorporating various sensors, the sweatainer can analyse sweat in a mode similar to previous wearable sweat-sensing systems.

Tyler Ray, Assistant Professor at the Department of Mechanical Engineering, said 3D printing enables an entirely new design mode for wearable sweat sensors by allowing researchers to create fluidic networks and features with enhanced complexity. “With the sweatainer, we are utilising 3D printing to showcase the vast opportunities this approach enables for accessible, innovative and cost-effective prototyping of advanced wearable sweat devices,” Ray said.

Traditional approaches for sweat collection use absorbent pads or microbore (very narrow) tubes pressed against the epidermis using bands or straps to capture sweat as it emerges from the skin. These techniques require trained personnel, special handling and costly laboratory equipment. The recent emergence of wearable sweat sensors has addressed some of these challenges, but these devices still remain single-use. When the device is full, it must be removed and the sweat collection be stopped.

The sweatainer also features a “multi-draw” sweat collection method, which allows for the collection of multiple, separate sweat samples for analysis either directly on the device or sent to a lab. Inspired by the vacutainer used in clinical blood sampling, this advancement makes sweat collection more efficient and opens up new possibilities for at-home testing, storing samples for future research and integrating with existing health-monitoring methods.

Field studies of the sweatainer system highlight the real-world potential of this technology. Through the blueprint established in the sweatainer, the researchers hope that this will continue to drive innovation to create a future where personal health monitoring is more accessible, convenient and insightful.

Image caption: Sweatainer on a person’s arm. Image credit: Roxanne Kate Balanay, Tyler Ray.