Wearable tesla valve-based sweat collection device for sweat colorimetric analysis

Area of Science:

• Biomedical Engineering
• Microfluidics
• Wearable Diagnostic Devices

Background:

• Stable sweat collection is crucial for accurate in vitro wearable diagnostic devices.
• Existing mechanical micro-valves for sealed sweat collection face challenges in machining stability and reusability.

Purpose of the Study:

• To develop a novel sweat collection chip utilizing Tesla valves for improved stability and reusability.
• To enhance sweat collection efficiency and prevent contamination in wearable diagnostic systems.

Main Methods:

• Incorporated Tesla valves, leveraging their diodicity to prevent backflow and external contamination.
• Optimized Tesla valve parameters (shunt angle, branch channels) for enhanced performance at low flow rates.
• Designed a sweat storage chamber with a baffle structure for maximum static storage area.
• Verified the chip design through flow experiments using methylene blue and methyl red indicators.
• Modified filter paper for colorimetric analysis of glucose and pH.

Main Results:

• The Tesla valve design effectively improved sweat collection and prevented backflow and external contamination.
• Optimized valve parameters boosted diodicity, especially under low flow conditions.
• The integrated sweat collection chip demonstrated successful flow control and storage.
• Colorimetric analysis of glucose and pH was achieved through filter paper modification.

Conclusions:

• The developed sweat collection chip offers a stable and reusable platform for wearable diagnostic devices.
• The use of Tesla valves presents a promising alternative to mechanical micro-valves for sweat analysis.
• This innovation provides new insights for advancing wearable sweat sensor technology.