A microfabricated low cost enzyme-free glucose fuel cell for powering low-power implantable devices

In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10 μA cm−2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2 μW cm−2 and has a sustainable power density of 1.5 μW cm−2 at 10 μA cm−2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.

► We developed a low-platinum, high current density abiotic glucose fuel cell.
► Stacked fuel cell design without a porous membrane separating the electrodes.
► Showed that there is an optimal inter-electrode gap for stacked fuel cell design.
► Showed the effect of increasing the cathode thickness on power density.