Abstract: The valve control unit of a fuel leakage preventing structure of the present invention includes first and second electrodes. The first electrode is attached to a first member that is movable. When a pressing force is applied to the first member to move, the first and second electrodes are brought into contact with each other, to cause conduction. The first and second electrodes are connected to a control device, and the control device opens a control valve when the first and second electrodes are put into a conducting state. As the control valve is opened and closed by a pressing force in this manner, a fuel solution can be easily supplied.

Abstract: Provided is a fuel cell that is high in performance capabilities of initial power generation and in volume power density, and produces a stable power. Between fixing plates, first and second cell portions are provided. The first cell portion includes an anode, a cathode, and a proton conductor, and the second cell portion includes an anode, a cathode, and a proton conductor. To a space formed by gas-liquid separation and permeable films, cathode spacers, and an anode spacer, a fuel solution is filled. The gas-liquid separation and permeable films are disposed between the fixing plate and the cathode, and between the fixing plate and the cathode. The cathode spacers are provided around the cathodes, respectively, and the anode spacer is provided between the anodes.

Abstract: A bio-fuel cell includes at least one bio-fuel cell element. The bio-fuel cell element includes an anode, a cathode, an anode container filled with the bio-fuel, a proton exchange membrane sandwiched between the anode and the cathode, and a guide plate. The cathode includes a catalyst layer. The catalyst layer includes a number of tube carriers having electron conductibility, a number of catalyst particles uniformly adsorbed on inner wall of each of the tube carriers, and proton conductor filled in each of the tube carriers. The tube carriers cooperatively define a number of reaction gas passages. One end of each of the tube carriers connects with the proton exchange membrane. The guide plate is disposed on a surface of the cathode away from the proton exchange membrane.

Abstract: A fuel cell (100) includes a cation exchange membrane (110), a first anion exchange membrane (120) and a second anion exchange membrane (130). The cation exchange membrane (110) has a first side and an opposite second side. The first anion exchange membrane (120) has a first exterior surface and an opposite first interior surface disposed along at least a portion to the first side of the cation exchange membrane (110). A catalyst (140) is embedded along the first exterior surface. The second anion exchange membrane (130) has a second exterior surface and an opposite second interior surface disposed along at least a portion to the second side of the cation exchange membrane (110). A catalyst (142) is embedded along the second exterior surface. A stack of fuel cells (700) include a first fuel cell (701) with an acidic first anode (714) that is electrically coupled to an alkaline second cathode (722) of a second fuel cell (720).

Abstract: A glucose fuel cell for reception into a given constrained volume of implantation in a vertebrate in which the glucose fuel cell has access to fluid containing glucose. The fuel cell includes an anode adapted to oxidize the glucose, a cathode adapted to reduce an oxidant, and a membrane disposed between the anode and the cathode and separating the anode from the cathode. At least one of the anode or cathode define a flexible sheet that is geometrically deformed to be receivable into the given constrained volume of implantation and increase volumetric power density. Related methods of making a glucose fuel cell of this type and implantable assemblies including the glucose fuel cell are also disclosed.

Abstract: In a fuel cell (1) including an anode electrode (10), a cathode electrode (12), a membrane (14) which has ionic conductivity and is disposed between the anode electrode (10) and the cathode electrode (12), an ion-conductive gel-like substance (15) is held between the cathode electrode (12) and the membrane (14) having ionic conductivity.

Abstract: A fuel cell has an anode and a cathode with anode enzyme disposed on the anode and cathode enzyme is disposed on the cathode. The anode is configured and arranged to electrooxidize an anode reductant in the presence of the anode enzyme. Likewise, the cathode is configured and arranged to electroreduce a cathode oxidant in the presence of the cathode enzyme. In addition, anode redox hydrogel may be disposed on the anode to transduce a current between the anode and the anode enzyme and cathode redox hydrogel may be disposed on the cathode to transduce a current between the cathode and the cathode enzyme.

Abstract: Methods, systems, and devices are disclosed for implementing a biofuel cell device for extracting energy from a biofuel. In one aspect, a biofuel cell device includes a substrate, an anode including a catalyst to facilitate the conversion of a fuel in a biological fluid in an oxidative process that releases electrons captured at the anode, thereby extracting energy from the fuel substance, a cathode configured on the substrate adjacent to the anode and separated from the anode by a spacing region, and a load electrically coupled to the anode and cathode via electrical interconnects to obtain the extracted energy as electrical energy.

Abstract: The designs of prototype batteries are described based on some biological Fenton reactions and the photo-excitation of singlet oxygen. The biological battery consists of hydrogen peroxide (or an acid) and ferrous gluconate complexed with a second ligand. Salts such as sodium chloride or ammonium chloride are used as the electrolyte. The photochemical battery uses an aqueous paste of ferrous gluconate with an additional ligand and is irradiated by light. The power of the battery is higher by adding small amount of titanium oxide to ferrous gluconate. The power of these batteries can be increased by using higher concentration of the chemicals or connecting multiple batteries in sequence and/or in parallel. Replacing ferrous ion with cupric ions increases the current of the battery by about 20 times.

Abstract: Disclosed is an improved biofuel cell having a cathode comprising a dual function membrane, which contains an oxygen oxidoreductase enzyme immobilized within a buffered compartment of the membrane and an electron transport mediator which transfers electrons from an electron conducting electrode to the redox reaction catalyzed by the oxygen oxidoreductase enzyme. The improved biofuel cell also has an anode that contains an oxidoreductase enzyme that uses an organic fuel, such as alcohol, as a substrate. An electric current can flow between the anode and the cathode.

Abstract: It is an object of the present invention to provide a microbial fuel cell capable of increasing a current density without employing a mediator. The microbial fuel cell 1 includes a 3-dimensionally structured agglomerate formed from conductive fine particles 2 and microorganisms 3. In the agglomerate 4, the conductive fine particles 2 disperse among pieces of Shewanella 3 and the conductive fine particles 2 are coupled to one another to hold Shewanella 3, thus forming the 3-dimensional structure as a whole. Accordingly, with respect to Shewanella 3, conductive fine particles 2 hold Shewanella 3a on a surface of an electrode 103 and even Shewanella 3b positioned vertically away from the surface of the electrode 103. Hence, it becomes possible that more pieces of Shewanella 3 are allowed to transfer electrons.

Abstract: Disclosed is a microbial fuel cell cathode assembly comprising a catalyst (6) and an electrically conductive catholyte wicking member (5) having a catalyst contacting surface (5a) in contact with the catalyst, an electrical contact region (5c) for contacting an electrical connector, and a catholyte supply region (5b) for receiving catholyte from a catholyte supply (9), wherein the electrically conductive catholyte wicking member is operable to wick received catholyte from the catholyte supply region to form a film of catholyte on a part of the surface of the catalyst such that a part of the surface of the catalyst is in contact with both the film of catholyte and a part of the surface of the catalyst is in contact with a gas pathway arranged to supply oxygen to the catalyst.

Abstract: A method for monitoring the metabolic state of an organelle in the presence of a potential organelle modulating agent is disclosed. A first organelle-modified bioelectrode is provided that is electrically coupled to a second electrode of opposite polarity in a circuit. The first bioelectrode is contacted with an aqueous carrier containing a biologically acceptable electrolyte and an effective amount of a potential organelle modulating agent and an effective amount of an organelle substrate. The substrate is reacted at the bioelectrode to form an ionic product that is released into the aqueous carrier-containing electrolyte to thereby provide a current at the second electrode when the circuit is closed. A metabolic flux data set is obtained during the reaction and is compared to a control metabolic flux data set obtained under the same conditions in the absence of the organelle modulating agent, thereby determining the metabolic state of the organelle.

Abstract: Provided is a method for producing a fuel battery in which an oxidoreductase has been fixed as a catalyst on at least one electrode of a negative electrode or a positive electrode, including conducting at least a step of preparing an electrode pattern, in which an electrode material containing at least electroconductive particles is printed on the surface of a bendable non-electroconductive sheet, and a step of preparing a negative electrode and a positive electrode, in which a negative electrode and a positive electrode are made by printing a predetermined oxidoreductase on the electrode pattern prepared in the step of preparing an electrode pattern.

Abstract: Disclosed herein is a flexible fuel cell including, one or a plurality of cell sections, and a sealing sheet covering the cell section or sections, wherein the cell section has, at least, a pair of electrode sheets which form an anode and a cathode and at least one of which is accompanied by an oxidoreductase present at a surface thereof, a separator which is disposed between the electrode sheets and which has a proton-permeable membrane, a pair of current collectors which are electrically conductively connected respectively to the electrode sheets with a conductive adhesive, and a fuel reservoir section which is provided at such a position as to make contact with the anode at least and in which a fuel solution containing a fuel component is reserved.

Abstract: A multicopper oxidase mutant having improved resistance to imidazole compounds is provided. A multicopper oxidase mutant, which comprises an amino acid sequence derived from the amino acid sequence shown in SEQ ID NO: 2 by substitution of either or both an amino acid residue corresponding to methionine at position 157 and an amino acid residue corresponding to proline at position 414 with a different amino acid and has activity of catalyzing a reaction generating water molecules via four-electron reduction of oxygen molecules using ABTS (2,2?-azinobis(3-ethylbenzoline-6-sulfonate)) as a substrate is provided.

Abstract: A microbial power generation device includes an anode chamber which maintains a microbe and which is supplied with influent which includes an electron donor, a cathode chamber supplied with an electron acceptor, a nonconductive membrane having a first face and an opposing second face and arranged between the anode chamber and the cathode chamber, a first electro-conductive support material having a rough surface which has asperity spreading close to the first face of the nonconductive membrane, and formed by a porous material having approximately the same shape as the interior of the anode chamber, and arranged within the anode chamber, and a second electro-conductive support material having a rough surface which has asperity spreading close to the second face of the nonconductive membrane.

Abstract: Provided is a fuel cell having a structure in which a cathode and an anode face each other with a proton conductor therebetween. In this fuel cell, an oxygen reductase or the like is immobilized on at least the cathode, and the cathode is composed of a material having pores therein such as porous carbon. In this fuel cell, the volume of water contained in the cathode is controlled to be 70% or less of the volume of the pores of the cathode, whereby a high current value can be stably obtained through optimization of the amount of moisture contained in the cathode when an enzyme is immobilized on at least the cathode. Also provided is a method for operating the fuel cell.

Abstract: Embodiments of the present methods may be used to produce energy in the form of an electrical current from water without the use of fossil fuel. Silicon hydride is very easy to make. This procedure in conjunction with an enzyme to produce hydrogen gas for fuel cells and other small devices. In fuel cells the production of protons may be bypassed, and an oxidant such as permanganate or oxygen from air may be used to drive the fuel cells. In such an embodiment, an intermediate reaction may not be needed to produce protons. In one embodiment, membrane-less laminar flow fuel cells with an external grid for oxygen supply from the air may be used.

Abstract: Provided is a floating-type microbial fuel cell capable of effectively generating energy from organic contaminants of contaminated waters. The floating-type microbial fuel cell includes a cathode, an anode electrically connected to the cathode, and a floating unit connected to the cathode and/or the anode and floatable in a substrate solution, wherein the cathode is positioned at a region in the substrate solution having a dissolved oxygen concentration higher than that of a region at which the anode is positioned, and the anode is positioned at a region in the substrate solution having an amount of electrons generated by microorganisms larger than that of a region at which the cathode is positioned.

Abstract: The present disclosure provides for a method of forming, producing or manufacturing functionalized and soluble nanomaterials, most specifically carbon nanotubes on a substrate, which can be used in the production or manufacture of biofuel cells. One embodiment provides for the coupling of biofuel cells with a nanomaterial, wherein the nanomaterial supports catalytic enzymes. Another embodiment provides for a biofuel cell which uses enzymes immobilized on nanomaterials as electrodes. Another embodiment provides for the construction of a biofuel cell, wherein the application of a microwave process, and/or an electrochemical technique, is used to develop a biofuel cell having nanomaterial/enzyme-based electrodes on a substrate. Another embodiment provides for a composite of nanomaterial grown on a substrate, coupled to tethered or bonded enzymes, which makes it possible to fabricate direct electron transfer electrodes. A method for producing a nanomaterial-substrate system is also disclosed.

Abstract: A method and apparatus are disclosed for generating electrical power during negative pressure therapy. The apparatus includes a fuel cell, comprising an anode element and a cathode element, arranged to collect biological fluid from a wound site to which a negative pressure is applied and electro-oxidize a component of the biological fluid at the anode element and/or electro-reduce a component of the biological fluid at the cathode element.

Abstract: A fuel cell has an anode and a cathode with anode enzyme disposed on the anode and cathode enzyme is disposed on the cathode. The anode is configured and arranged to electrooxidize an anode reductant in the presence of the anode enzyme. Likewise, the cathode is configured and arranged to electroreduce a cathode oxidant in the presence of the cathode enzyme. In addition, anode redox hydrogel may be disposed on the anode to transduce a current between the anode and the anode enzyme and cathode redox hydrogel may be disposed on the cathode to transduce a current between the cathode and the cathode enzyme.

Abstract: Disclosed herein is a membraneless micro fuel cell. A cathode fluid and an anode fluid with a low Reynolds number flowing along a cathode channel and an anode channel are formed to have an interface with each other through a micro passageway and to be mixed by only diffusion so that the direct mixing of the cathode fluid and the anode fluid is prevented, making it possible to prevent reactants from being depleted at an electrode surface as well as to increase the efficiency of the fuel cell.

Abstract: A microbial fuel cell includes an anode portion having an anode and a cathode portion having a cathode. The anode is configured to support an electrically conductive biofilm matrix. A cation exchange membrane is positioned between the anode and the cathode. The anode portion and the cation exchange membrane define an anode chamber having a volume of between about 1 ?L and about 100 ?L and configured to receive an anolyte. The cathode portion and the cation exchange membrane define a cathode chamber having a volume of between about 1 ?L and about 100 ?L and configured to receive a catholyte. The microbial fuel cell is configured to achieve a Coulombic efficiency of at least 30% and/or a power density of at least of 4.7 ?W/cm2. The microbial fuel cell is a microelectromechanical system and can be fabricated in an automated production process.

Abstract: A printed energy storage device includes a first electrode, a second electrode, and a separator between the first and the second electrode. At least one of the first electrode, the second electrode, and the separator includes frustules, for example of diatoms. The frustules may have a uniform or substantially uniform property or attribute such as shape, dimension, and/or porosity. A property or attribute of the frustules can also be modified by applying or forming a surface modifying structure and/or material to a surface of the frustules. The frustules may include multiple materials. A membrane for an energy storage device includes frustules. An ink for a printed film includes frustules.

Abstract: A cathode for a fuel cell comprising a catalyst layer; a backing layer mounted to an aperture in a fuel chamber of said fuel cell; 1) wherein said catalyst layer is mounted to the backing layer on a face opposed to the aperture, so as to be in fluid communication with atmospheric oxygen in the case of microbial fuel cell; and 2) wherein said catalyst layer is mounted to the backing layer on a face opposed to the aperture, so as to be in fluid communication with water in the case of microbial electrolysis cell.

Abstract: An anode/cathode system is disclosed for use in a Benthic microbial fuel cell. Carbon cloth forms at least a portion of the anode and is disposed on one side of a water oxygen impermeable layer, which can be weighted around a periphery thereof to hold the anode against a water-sediment interface. Carbon cloth flaps or strands can be attached to the other side of the impermeable layer to form the cathode. The anode and cathode can be divided into sections with each section having an electrical lead coupled thereto. The system is deployed onto the seafloor with the anode side in contact with the water-sediment interface.

Abstract: The present invention relates to a novel bilirubin oxidase from Magnaporthe oryzae, to the method of preparation thereof as well as use thereof notably for assay of bilirubin and for the application of enzymatic biofuel cells.

Abstract: A microbial fuel cell comprising a cathode module, an anode module, a means for feeding source water to the anode module, and a means for feeling air to the source water after said anode module, wherein the source water is introduced in the anode module and discharged at the cathode module, a membrane is not used to transfer electrons, and the source water does not flow through a layer between the cathode and anode modules, such as glass wool or beads.

Abstract: A fuel cell has an anode and a cathode with anode enzyme disposed on the anode and cathode enzyme is disposed on the cathode. The anode is configured and arranged to electrooxidize an anode reductant in the presence of the anode enzyme. Likewise, the cathode is configured and arranged to electroreduce a cathode oxidant in the presence of the cathode enzyme. In addition, anode redox hydrogel may be disposed on the anode to transduce a current between the anode and the anode enzyme and cathode redox hydrogel may be disposed on the cathode to transduce a current between the cathode and the cathode enzyme.

Abstract: The catalytic electrode of the present invention does not cause mass transfer resistance, unlike conventional catalytic electrodes coated with Nafion or the like, and thus can achieve significantly high electron transfer efficiency. Accordingly, the catalytic electrode can have high power density, and thus has excellent physical properties.

Abstract: Provided is a fuel cell capable of preventing elution of nicotinamide adenine dinucleotide and/or a derivative thereof immobilized on an electrode, and capable of preventing performance degradation due to elution, and a method for manufacturing the fuel cell. A biofuel cell having a structure in which a positive electrode and a negative electrode face each other via a proton conductor, the biofuel cell configured so that an enzyme is used to extract electrons from a fuel, wherein the negative electrode is configured from an electrode including carbon and/or an inorganic compound having pores with a size of 2 nm or more and 100 nm or less on the surface, nicotinamide adenine dinucleotide and/or a derivative thereof being immobilized on the carbon and/or the inorganic compound. A carbon particle, a carbon sheet, or carbon fiber is used as the carbon.

Abstract: An aerobic microbial fuel cell anode electrode, a fuel cell using the anode, and methods of use. An anode electrode having a conductive exterior surface and having sufficient porosity to allow a fuel-bearing liquid flowing in a cavity within the anode to escape and to supply fuel to a biologically active microbe film grown on the exterior of the anode is situated in the fuel cell. When operated in an aerobic environment, such as water, the anode and a cathode can supply electrical power to a load without the need for a semi-permeable membrane between the anode and the cathode. Several embodiments in which the anode electrode is machined from a graphite block or cylinder are described. Conditions for growing the biologically active film and for operating the fuel cell are described.

Abstract: The present disclosure provides biological fuel cells comprising a paper-based fuel delivery layer which delivery fuel to the biological anode and cathode via capillary action and/or evaporation. In some embodiments the paper-based fuel delivery layer incorporates an outwardly extending fan-shaped region which enables a constant volumetric flow rate through the cell.

Abstract: The present disclosure provides photosynthetic electrochemical cells including photosynthetic compounds and methods of generating an electrical current using the photosynthetic electrochemical cells.

Abstract: The present invention concerns bio-nano power cells and methods of their manufacture and use. More particularly, the present invention relates to the preparation of bio-nano power cells that are biocompatible and capable of producing flash, intermittent, or continuous power by electrolyzing compounds in biological systems.

Abstract: A direct fuel cell comprises a cathode comprising electroactive catalyst material; and an anode assembly comprising an anode having a porous layer and electroactive catalyst material in the porous layer. The electrode characteristics of the anode assembly are selected so that fuel supplied to the anode is reacted within the anode so that cross-over from the anode to the cathode does not have more than a 10% negative effect on voltage or a 25 mV voltage loss when at peak power and steady state conditions. The anode and cathode each have a first major surface facing each other in non-electrical contact and without a microporous separator or ion exchange membrane therebetween.

Abstract: A current producing cell has anode flow plates 22 and cathode flow plates 20. Each of the flow plates 20, 22 defines a membrane face 26, a collector face 24, and a center axis C perpendicular to the membrane face 26 and the collector face 24. Each of the collector faces 24 define a plurality of cooling channels 74, 76, 78 and a plurality of transport channels 62, 64. The cooling channels 74, 76, 78 of the cathode flow plates 20 extend radially relative to the center axis C thereof to overlap the transport channels 62, 64 of the anode flow plates 22.

Abstract: Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce a carbohydrate solution that can be used in a fuel cell, e.g., a direct glucose fuel cell.

Abstract: A fuel cell includes an anode including a current collector and microorganisms; a cathode; and a source of a sulfur-containing compound; wherein the fuel cell is poised for the microorganisms to selectively oxidize the sulfur-containing compound to elemental sulfur. Purification of a sulfur-contaminated fuel may be completed using such fuel cells. A method of carbon sequestration includes providing a fuel cell that includes a cathode including a conductor and oxygen; and an anode including a current collector and microorganisms; and introducing carbonic acid to the cathode to react with the oxygen to produce water and a carbonate or bicarbonate salt.

Abstract: A fuel cell comprising: at least one microfluidic channel that allows the capillary flow of at least one suitable fluid for generating electricity, at least one receiving absorbent region coupled to each microfluidic channel, at least one collecting absorbent region coupled to each microfluidic channel, a cathodic zone coupled to each microfluidic channel, and an anodic zone coupled to each microfluidic channel, where each receiving absorbent region and each collecting absorbent region are coupled to one of the microfluidic channels such that when a fluid suitable for generating electricity is deposited in the receiving absorbent region, it flows by capillary action through the microfluidic channel to reach the collecting absorbent region where it is absorbed. As well as an analysis device comprising one or more of these fuel cells.

Abstract: The invention provides molecules useful for enhancing charge transport across membranes, such as electron transport across membranes, and methods of using such molecules, for example in improving the performance of a microbial fuel cell or in staining microbes for observation. The amphiphilic molecule comprises a conjugated core with hydrophilic groups on either end. The amphiphilic molecule inserts into the membrane of a microbe and facilitates charge transfer across the membrane of the microbe.

Abstract: The present invention is directed to a method for cleansing fuel processing effluent containing carbonaceous compounds and inorganic salts, the method comprising contacting the fuel processing effluent with an anode of a microbial fuel ell, the anode containing microbes thereon which oxidatively degrade one or more of the carbonaceous compounds while producing electrical energy from the oxidative degradation, and directing the produced electrical energy to drive an electrosorption mechanism that operates to reduce the concentration of one or more inorganic salts in the fuel processing effluent, wherein the anode is in electrical communication with a cathode of the microbial fuel cell. The invention is also directed to an apparatus for practicing the method.

Abstract: Disclosed is a high surface area electrode for use in a microbial fuel cell. In one embodiment the high surface area electrode has an electrode backing and villiated extensions attached to the backing. In one embodiment the villiated extensions and/or electrode backing are made of an electro conductive material such as, for example, graphite or graphite fibers. In one embodiment the electrode is an anode and the electrode backing is in the form of a mesh or woven structure. The electrodes offer superior removal of chemical oxygen demand (COD) and are thus useful in the remediation of wastewaters. The invention also provides microbial fuel cells that utilize the electrodes of the invention. In one embodiment the microbial fuel cells utilize an oxygen barrier and do not utilize a cation or anion or proton exchange membrane.

Abstract: A fuel cell has an anode and a cathode with anode enzyme disposed on the anode and cathode enzyme is disposed on the cathode. The anode is configured and arranged to electrooxidize an anode reductant in the presence of the anode enzyme. Likewise, the cathode is configured and arranged to electroreduce a cathode oxidant in the presence of the cathode enzyme. In addition, anode redox hydrogel may be disposed on the anode to transduce a current between the anode and the anode enzyme and cathode redox hydrogel may be disposed on the cathode to transduce a current between the cathode and the cathode enzyme.

Abstract: A housing includes a body with a first silicon element and a second porous silicon element, at least one first cavity provided in the porous silicon element, a first electrically conducting contact area electrically coupled to at least a portion of at least one internal wall of the at least one first cavity, and a second electrically conducting contact area electrically coupled to a different portion of the at least one internal wall of the second porous silicon element of the at least one first cavity, wherein the two contact areas are electrically isolated from each other.

Abstract: A bacterial fuel cell including at least one anode and at least two cathodes in liquid communication with a liquid to be treated, the at least one anode being separated from the at least two cathodes by at least first and second electrically insulating spacers and the at least one anode and the at least two cathodes being electrically connected across an external load and the at least one anode and the at least two cathodes being wound together generally in a spiral configuration together with at least a third electrically insulating spacer.

Abstract: A photoelectromethanogenic microbial fuel cell apparatus for processing a carbon dioxide flow into electricity and methane. The apparatus comprises: (a) a photosynthetic microbial fuel half-cell component having an electron-conductive anode and a photosynthetic microbial culture for converting light and water into oxygen, protons and electrons; (b) an electromethanogenic microbial fuel half-cell component having an electron-conductive cathode and a methanogenic microbial culture for converting a flow of carbon dioxide into methane using electrons and protons produced in the photosynthetic microbial fuel half-cell; (c) an electrical coupling interconnecting the two microbial fuel half-cells; and (d) an ionic coupling with an ionic separator interconnecting the two microbial fuel half-cells for selectively transporting ions between the microbial fuel half-cell components.

Abstract: Improved nanotube devices and systems/methods for fabrication thereof are provided. The present disclosure provides systems/methods for depositing controlled numbers of nanotubes with specific properties at predefined locations for the fabrication of nanotube devices. The nanotube devices may be utilized in a range of applications. A bio-fuel cell system that does not require a proton exchange membrane separator and does not need a mediator to transfer charge is provided. This exemplary bio-fuel cell uses enzyme functionalized SWNTs for the anode/cathode. The absence of a membrane in the bio-fuel cell configuration opens up the possibility of other configurations that would otherwise be unfeasible. This includes a bio-fuel cell where the anode/cathode are on the same substrate. Since the electrodes can share the same substrate, the configuration may be integrated with a circuit device on the same substrate. An IC and its power source may be fabricated on the same silicon wafer.