Paper-based mediatorless enzymatic microfluidic biofuel cells

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Traditional enzymatic fuel cells (EFCs) often involve toxic mediators and complex fabrication, increasing cost and environmental impact.
• There is a growing need for low-cost, disposable, and environmentally friendly power sources for portable diagnostic devices.

Purpose of the Study:

• To develop mediatorless, paper-based microfluidic EFCs using eco-friendly materials.
• To investigate the effect of glucose concentration on EFC performance.
• To optimize EFC design for high power and current density.

Main Methods:

• Immobilization of glucose oxidase and laccase enzymes onto multi-walled carbon nanotube electrodes.
• Fabrication of Y-shaped and cross-shaped microfluidic EFCs using micromachining techniques.
• Performance evaluation through experimental measurements of power and current density at varying glucose concentrations.

Main Results:

• Achieved a maximum power density of 104.2 ± 3.35 μW cm⁻² and current density of 615.6 ± 3.14 μA cm⁻² with a Y-shaped channel at 100 mM glucose.
• Demonstrated that increased glucose concentration leads to decreased fuel stream flow speed, impacting cell performance.
• The developed paper-based EFCs represent the highest performance reported for single, paper-based EFCs to date.

Conclusions:

• Mediatorless, paper-based microfluidic EFCs offer a cost-effective and eco-friendly alternative for portable power.
• The Y-shaped channel design and optimized glucose concentration are crucial for maximizing performance.
• These EFCs show significant potential for powering miniaturized, on-site diagnostic devices.