Nowadays, the explosive growth of portable, wireless consumer electronics and biomedical devices has boosted the development of new micro power sources able to supply power over long periods of time. Miniature biofuel cells are considered as promising alternative to power supply in wireless sensor networks. However, the miniaturization of biofuel cells imposes significant technical challenges based on fabrication techniques, cost, design of the device, and nature of the materials. These devices must provide similar performances to larger biofuel cells in terms of efficiency and power density while using less reagents, space and time consumption. Key components in the design of biofuel cells are the active materials that catalyze the electrode reactions of fuel at the anode and of oxygen at the cathode. Whereas enzymatic catalysts offer high reactant specificity and high reaction rate, the limited stability of enzymes makes difficult long-term operation. An alternative option is the use of abiotic catalysts like gold nanoparticles that are less specific but present high stability with time. Besides, carbon nanotubes represent an interesting type of carbon material due to their structural, mechanical, chemical and electronic properties. They possess high surface area, excellent electronic conductivity, high chemical and thermal stability. They represent an alternative and efficient material as carbon support both for metal nanoparticles and enzyme immobilization. The novelty of our approach concerns the use of the best electrode material in the development and design of a new generation of miniature glucose/O2 biofuel cells able to deliver power densities > 1 mW/cm2. At the anode, glucose will be oxidized by gold nanoparticles/carbon nanotubes based electrode and at the cathode, oxygen will be reduced by enzymes supported on carbon nanotubes electrode. The hybrid biofuel cells will be miniaturized by using microfabrication techniques to include all the fundamental components (fluid and electrodes) in a microfluidic chip. The microfluidic biofuel cells will be featured with channels in poly(dimethylsiloxane) of sub-millimeter in height fabricated by rapid prototyping, using standard soft lithography procedure. These devices operate with parallel flow of the fuel and oxidant streams within the microchannel in laminar regime without mixing. Indeed, the advantage of the co-laminar flow is to choose the composition of the two oxidant and fuel streams independently for optimum electrode activity and stability to improve reaction rates and current density. The fabrication of these systems is ideal because of its well proven cost-effectiveness, reproducibility and precision. If mass produced in high volume, mirofluidic enzymatic devices would be cost-effective and therefore disposable. The use of this kind of catalysts may lead to the development of new applications, particularly in the field of low power micro-electromechanical systems.