A 1.5 microL microbial fuel cell for on-chip bioelectricity generation

Area of Science:

• Bioengineering
• Electrochemistry
• Microfluidics

Background:

• Microbial fuel cells (MFCs) offer a sustainable energy source by converting microbial metabolism into electricity.
• Scaling down MFCs presents challenges in maintaining efficiency and facilitating bacterial culture.
• On-chip bioenergy generation is crucial for powering micro- and nano-scale devices.

Purpose of the Study:

• To develop and characterize the smallest dual-chamber microfluidic microbial fuel cell (MFC) system.
• To demonstrate on-chip bacterial culture and electricity generation.
• To investigate the potential for powering nanodevices using micro-scale bioenergy.

Main Methods:

• Development of a vertically stacked, dual-chamber microfluidic device (1.5 µL anode, 4 µL cathode).
• Microfluidic delivery of growth medium and catholyte without cross-channel exchange.
• Inoculation with electrogenic Shewanella oneidensis strain MR-1 and monitoring current generation over time.
• Electron microscopy to analyze biofilm formation on the anode.

Main Results:

• Achieved current generation for up to two weeks with repeatable production upon substrate replenishment.
• Reached a maximum current density of 1300 A/m³ and power density of 15 W/m³.
• Confirmed uniform, large-scale biofilm growth on the gold anode, suggesting accelerated start-up due to enhanced cell/anode interaction.

Conclusions:

• The developed microfluidic MFC is a versatile platform for micro-scale MFC research.
• The system demonstrates efficient on-chip bacterial culture and electricity generation.
• This technology shows promise for powering micro- and nanodevices using bioenergy.