A Flexible Tough Hydrovoltaic Coating for Wearable Sensing Electronics

Area of Science:

• Materials Science
• Nanotechnology
• Energy Harvesting

Background:

• Evaporation-driven hydrovoltaic effect is limited by poor nanomaterial binding in wearable electronics.
• Improving mechanical toughness and flexibility of hydrovoltaic devices is challenging without compromising nanostructures.

Purpose of the Study:

• To develop a flexible and tough hydrovoltaic coating for wearable sensing applications.
• To enhance both electricity generation and ion-sensing capabilities of hydrovoltaic devices.

Main Methods:

• Fabrication of a flexible tough polyacrylonitrile/alumina (PAN/Al2O3) hydrovoltaic coating.
• Characterization of electricity generation (open-circuit voltage) and ion-sensing performance.
• Evaluation of mechanical toughness under water-flow impact.

Main Results:

• Achieved open-circuit voltage (Voc) ≈ 3.18 V and sensitive ion sensing (2285 V M−1 for NaCl).
• PAN provides strong binding, 4 times that of Al2O3 film, withstanding 9.92 m s−1 water-flow impact.
• Developed skin-tight and non-contact device structures for wearable self-powered sensing using sweat.

Conclusions:

• The flexible tough PAN/Al2O3 hydrovoltaic coating overcomes mechanical brittleness limitations.
• Broadens applications of the evaporation-induced hydrovoltaic effect in self-powered wearable sensing electronics.
• Enables multifunctional self-powered sensing directly using sweat for wearable devices.