Implantable Biofuel Cell

Implantable medical devices ¿ such as pacemakers, nerve stimulators, drug delivery pumps, and biosensors ¿ offer tremendous patient benefits. However, the batteries currently used to supply power to these devices have a large footprint and a limited lifetime, requiring periodic surgical replacement. In addition, the development of miniature implantable devices is constrained by the size and energy density of current implantable battery technologies. The biofuel cell is a new technology that can provide much higher energy densities and smaller footprints than batteries for powering implantable medical devices. These less intrusive implantable devices can extend the lifetime of implantable devices and reduce or eliminate the need for additional surgery needed for battery replacement. This project will develop a miniature biofuel cell that uses two enzymatic systems at the anode and cathode and is powered by glucose and oxygen found in the human blood stream. Both the biofuel cell materials and by-products will be non-toxic and bio-compatible with the human body. During Phase I, the enzymatic anode and cathode were successfully developed and tested, and bio-compatible polymer coatings were developed to enhance cell performance and stability. A working biofuel cell, which operates on glucose and oxygen, was fabricated, and the cell demonstrated an open circuit potential of 0.5 V and power densities up to 300 µW/cm2. Phase II will optimize the biofuel cell components (e.g., enzymatic electrodes and bio-compatible polymers) to enhance power density and long-term stability. A prototype miniature biofuel cell will be designed, fabricated, and tested. The design will allow the biofuel cell to be easily implanted into a blood vessel with minimal disruption of blood flow. The miniature prototype biofuel cell will be tested in serum and defribinated blood, in order to demonstrate the ability of the biofuel cell to operate in vivo. Commercial Applications and Other Benefits as described by the awardee: Enzymatic biofuel cells should have broad commercial impact on the biomedical industry, based on their ability to provide power to a wide range of implantable devices: pacemakers, cardioverter defibrillators, nerve stimulators, biosensors, glucose monitors, etc. In addition, biofuel cells could provide a versatile, renewable power supply for portable electronics and other applications, using readily available carbohydrate fuels and non-precious metal catalysts.