Dual functions of a microfluidic fuel cell as electricity generation and liquid pumping units†

Microfluidic chip technology has attracted considerable attention in the field of biochemical detection and analysis due to its advantages of low cost, fast response and high sensitivity. However, the poor integration of power supply units and fluid pulsation at low flow rate are two challenges in chip integration. Microfluidic fuel cells represent emerging power generators based on microfluidic control technology and can convert the chemical energy of fuel into electricity while producing a gaseous product. In this work, a microfluidic fuel cell is first integrated into a chip-based analysis system, where the fuel cell serves as a power-supply unit and the generated gaseous product is used as a stable bubble pump to drive detection sample flow. A maximum power density of 28.8 mW cm⁻² and current density of 147.5 mA cm⁻² are achieved, and the detection sample is driven stably and continuously at a flow rate of 5 mm s⁻¹. This approach effectively addresses the issue of insufficient integration of the power supply system and initially achieves stable sample pumping at a low flow rate. The design paves the way for practical uses of microfluidic fuel cells, following few previous attempts, and casts new light on structure design and system integration.