Background

Digital wellness wearables have the capability to collect real-time data that reveal the physical and chemical properties of the body to evaluate vital signs of health. These advancements in the development of wearable sensors are helping millions detect and manage chronic health conditions and avoid serious illness on devices small enough to be worn conveniently on the body.

Additive manufacturing processes, particularly stereolithography (SLA)-based printing, have recently been shown to overcome limitations of current fabrication methods by reducing time and cost for manufacturing while expanding the design capacity for novel device architectures with 3D designs (vs. traditional 2D layouts). As a result, an emerging class of wearable devices integrates microfluidic lab-on-chip designs with low-modulus materials, colorimetric assays, and electrochemical sensors to support the real-time, non-invasive analysis of sweat. Such skin-interfaced microfluidic systems offer extensive capabilities for a personalized assessment of health, nutrition, and wellness through the non-invasive, real-time analysis of sweat.

Technology Overview

Researchers at the University of Hawai’i have developed a ‘sweat sticker’ using a streamlined and simplified 3D-printing prototyping process to fabricate soft, flexible, and stretchable devices with a multilayered design that can conform to the skin spanning all ages, from infants to adults. This rapid fabrication approach enables the integration of spatially-engineered features that support the collection of sweat within the device and via multiple devices, for multiple sweat collection if needed (e.g., similar to multiple collection containers during a venous blood draw) in a single setting, which can then be subsequently analyzed using a smartphone application.

Successful demonstrations showed:

• Colorimetric readout, which enables real-time image analysis using a smartphone for diagnosis
• Sweat collection is as effective as traditional methods
• Validation benchtop and on-body testing on healthy adults maintained conformity to the skin during physical activity without leakage

This innovative ‘sweat sticker’ design may be employed in a wide array of applications for evaluating and diagnosing health conditions.

Stage of Development

Technology Readiness Level (TRL): 4

Further Details

• Wu et al, Science Advances, 2023;
• News Release, 2023

Benefits

• Real-time assessment
• Non-invasive
• Multiple sample collection in single setting
• Rapid fabrication time
• Low cost
• Modular design
• User friendly
• Mobile device accessible

Applications

• Wearable technologies
• Healthcare and wellness diagnostics