Switchable Biofuel Cells Controlled by Biomolecular Computing Systems
Almost every existing device includes either a control or a self-regulation system. This is also the case of a new alternative energy source, the biofuel cells. Fuel cells take advantage of natural existing compounds in biofluids and transform them into energy available in situ. Although being a promising approach to solve energy supply, particularly in small implantable devices, these systems does not produce enough energy to support a conventional computing system together with their natural functionality. Enzyme biocomputing is an unconventional computing approach that assembles enzyme-catalyzed chemical reactions into Boolean logic operations, therefore can enhance the applications of biofuel cells. Enzyme logic gates can control a switch responsible of the biofuel cell power output in such a way that each specific combination of input signals–related to physiological conditions– determine whether the biofuel cell must provide energy or not and provoke an in situ real time response, i.e. drug release. Herein I review the most significant advances from the most basic enzyme logic gates to a final prototype of implantable biofuel cell controlling an acetaminophen dispenser depending on biologic marker inputs.
Keywords: Biofuel cell, enzyme logic, implantable devices, switchable electrodes