Fig. 2From: Vapor-fed bio-hybrid fuel cellCurrent density versus ethanol partial pressure. Concentrations of ethanol in the bubbling solution are given at the top of the graph. The line is drawn to guide the eye. The error bars represent the standard deviation of three independent runs. As ethanol partial pressure increases, the current density increases, until a maximum is reached at 3.5 mmHg and 13.6 mA/cm2 Back to article page