Fluid Sensor Based on Humidity- Responsive Fiber Zinc-Air Battery

Area of Science:

• Materials Science
• Electrochemistry
• Wearable Technology

Background:

• Noninvasive fluid sensing is crucial for precision medicine, enabling real-time physiological monitoring.
• Developing efficient, sensitive, and convenient fluid sensors remains a key research challenge.
• Wearable sensors require robust electrolytes with excellent mechanical and retention properties.

Purpose of the Study:

• To introduce a unique wearable fiber Zinc-air battery (ZAB) with integrated humidity and liquid monitoring capabilities.
• To evaluate the performance and durability of the ZAB's eutectic gel polymer electrolyte.
• To demonstrate the practical application of the fiber ZAB in wearable devices and physiological monitoring.

Main Methods:

• Fabrication of a fiber Zinc-air battery utilizing a eutectic gel polymer as electrolyte and sensing element.
• Characterization of the gel electrolyte's properties, including water retention, mechanical strength, and flexibility.
• Integration of the fiber ZAB into fabric for powering a digital watch and monitoring urine levels in diapers.

Main Results:

• The eutectic gel polymer served effectively as both battery electrolyte and sensing element.
• The gel electrolyte demonstrated high water retention (94.2%) and excellent mechanical properties (16.1 kPa fracture strength, 541% elongation at break).
• The flexible fiber ZAB was successfully woven into fabric, powering a watch and responding to liquid presence.

Conclusions:

• The developed wearable fiber ZAB offers a promising solution for noninvasive, continuous physiological monitoring.
• The unique gel electrolyte provides stability, durability, and sensing capabilities for wearable applications.
• This work presents a novel approach for integrating power sources and sensors into textiles for advanced wearable systems.