Biological Battery

Abstract

A biological battery consists of uniformly-polarized biological cells capable of generating an electrochemical gradient compartmentalized into single layers which are separated from each other by sections of membrane capable of converting the energy contained within an electrochemical gradient into electrical current. This arrangement of stacked cell layers is encapsulated by an ultrafiltration membrane permeable to monosaccharides and amino acids but not large proteins. This enables the biological cells contained within to survive and generate the electrochemical gradients needed for power, but prevents an immune response against them by the organism it is implanted in. Biological batteries produce electrical energy capable of powering a circuit from an organism's own bodily chemical energy, thus eliminating the need for external power sources to power an implanted electronic device.

Claims

1. A system capable of generating electrical current from a biologically-generated electrochemical gradient produced by biological cells that can generate an electrochemical gradient across a compartment of space.

2. A process by which electrochemical gradient generating biological cells (ECGGBCs) are encapsulated within a biocompatible membrane permeable to small molecules such as glucose and amino acids but impermeable to proteins which provides them with the chemical material needed to survive and function but prevents the encapsulated ECGGBCs from initiating an immune response.

3. A process by which ECGGBCs are arranged in compartmentalized layers and directionally polarized with uniform orientation in order to generate an electrochemical gradient across sections of membrane which separate adjacent compartments.

4. A process by which encapsulated ECGGBC layers are stacked together and divided from each other by membranes capable of generating electrical energy from an electrochemical gradient across them.

5. A process by which energy stored in an electrochemical gradient generated by ECGGBCs, across membranes capable of generating electrical current from an electrochemical gradient across them, is converted into electrical energy capable of powering an electronic device.

Description

DRAWING

[0010] FIG. 1:

[0011] Here is displayed the outside of a linear biological battery. This is a membrane (Membrane Type 1) permeable to small molecules like carbohydrates and amino acids, but impermeable to proteins (such as immunoglobulins). The arrows on all sides indicate that the battery can be scaled in any dimension (or any combination of dimensions) to accommodate almost any desired geometry for various applications. In addition, the positive and negative leads sticking out of the battery can be modified to accommodate various applications as well. Leads can be connected in any combination of parallel or series to produce the desired output current and voltage needed for a specific application.

[0012] FIG. 2:

[0013] This image shows the outer semipermeable membrane (Membrane Type 1) partially removed to show a simplified, linear biological battery (the equivalent of a single cell in a normal battery). Notice two parallel oxyntic cell layers (OCLs) separated by a membrane permeable to HCO.sub.3 (Membrane Type 2). Membrane Type 2 can be distinguished by the positive and negative leads attached to it. On the outsides of the OCLs lie sections of Membrane Type 1. In reality, all the illustrated sections of Membrane Type 1 would be continuous (as in FIG. 1) and form a barrier to separate the outside cellular environment from the one contained within the battery, allowing nutrients needed for the biological function of the oxyntic cells contained within to diffuse through, but acting as a barrier to proteins like antibodies. Membrane Type 1 also forms continuous perimeter connections with all sections of Membrane Type 2, thus isolating OCLs into a discrete volume known as an OCL compartment. The oxyntic cells share a direction of polarization, which ensures that the ions being pumped to each side of an OCL compartment are of the same kind. In the case of oxyntic cells, this means that H.sup.+ ions are pumped to one side of the OCL compartment and HCO.sub.3.sup.− ions are pumped to the other. Oxyntic cells within the OCL compartments would be packed in tightly enough that they would be flush with adjacent cells and would form cell-to-cell adhesive junctions that divide the OCL compartment into two sub-compartments, thus reducing the mixing of H.sup.+ and HCO.sub.3.sup.− within the OCL compartment as much as possible, which serves to maximize efficiency.

[0014] FIG. 3:

[0015] Here can be seen a simplified view of two oxyntic cells abutting section of Membrane Type 2, which is capable of converting the energy stored in a conjugate acid-base gradient into electrical energy needed to power a circuit (as described in patent U.S. Pat. No. 4,311,771A). The uniform direction of polarization of OCLs means that the apical sides (which pump H.sup.+ out of the cell) of oxyntic cells in one chamber abut the basilar sides (which pump HCO.sub.3.sup.− out of the cell) of oxyntic cells in a neighboring compartment. Membrane Type 2 separates these two compartments and can convert the ion gradient generated across it into electrical energy. In nature, oxyntic cells, found in stomach epithelium, are polarized so that their basilar side moves HCO.sub.3.sup.− into the body via a Cl.sup.−/HCO.sub.3.sup.− exchanger and their apical side pumps H.sup.+ into the stomach lumen using the protein H.sup.+/K.sup.+ ATPase, thus acidifying gastric juices. Oxyntic cells in this battery would have their polarization artificially induced after being placed in compartments. In addition, the oxyntic cells would be immortalized, which would provide a long life for the battery once implanted by ensuring the oxyntic cells which generate the ion gradient that powers it do not die in vivo.

[0016] In addition, FIG. 3 also illustrates the biochemical pathway by which HCO.sub.3.sup.− and H.sup.+ are formed from water (H.sub.2O) and carbon dioxide (CO.sub.2) within oxyntic cells. These cells are known to produce a large amount of the enzyme carbonic anhydrase (represented by CA in FIG. 3), which functions to catalyze the conversion of carbon dioxide and water into carbonic acid (H.sub.2CO.sub.3) in a reversible reaction (carbonic anhydrase is incorrectly included as a reagent in the reaction illustrated on the left side of FIG. 3 due to the fact that there was no way to place it above the arrow yet its role is significant enough that it should be included as a part of the reaction). Carbonic acid dissociates into HCO.sub.3.sup.− and H.sup.+ in yet another reversible reaction. The arrows drawn in this illustration are shown to be one way because the internal concentrations of products (HCO.sub.3.sup.− and H.sup.+) are kept low by constant efflux through H.sup.+/K.sup.+ ATPase and Cl.sup.−/HCO.sub.3.sup.− exchangers. Thus, the net reaction in oxyntic cells is unidirectional as products are constantly being removed from the cell.

[0017] The mechanism by which electrical current is produced using Membrane Type 2 is also illustrated here. An electron dissociates from HCO.sub.3.sup.− when it comes in contact with the surface of Membrane Type 2 and subsequently traverses a circuit to reach the opposite surface abutting the high H.sup.+ concentration. After losing its excess electron, neutral HCO.sub.3 can cross Membrane Type 2 and recombine with H to form carbonic acid (H.sub.2CO.sub.3). Thus, in the region near Membrane Type 2, high concentrations of HCO.sub.3.sup.− and H.sup.+ (able to recombine by passing through Membrane Type 2) drive the formation of H.sub.2CO.sub.3 due to the fact that the two are in equilibrium. Then, this surplus H.sub.2CO.sub.3, due to the fact that it is in equilibrium with CO.sub.2 and H.sub.2O, drives the reaction towards the formation CO.sub.2 and H.sub.2O, dissociating to equilibrium as well. Thus, the net direction of the reaction outside of the oxyntic cells is towards the formation of CO.sub.2 and H.sub.2O, exactly opposite of the same reaction occurring inside of the (biological) cell. Notice that Membrane Type 2 has contacts with an electrical circuit that powers a load. In practice, this would probably be an implanted device of some kind, thus allowing implanted circuitry to be powered by the body's own chemical energy. Oxyntic cells feed off the carbohydrates and fatty acids of the body to create ion gradients whose potential is converted into electrical energy capable of powering a circuit.

[0018] FIG. 4:

[0019] This illustration shows a simplified circuit diagram of a biological battery comprising 5 OCLs wired in parallel, which is powering an attached electrical device using chemical energy from the body. Carbohydrates and fatty acids that diffuse through the encapsulating ultrafiltration membrane (Membrane Type 1) give the biological cells energy. Amino acids which diffuse through provide the necessary building blocks of cellular machinery. This allows the immortalized oxyntic cells (represented by the oval shapes) to survive and pump ions to different sides of their respective OCL compartments, thus generating a gradient of a conjugate acid-base pair across a membrane (Membrane Type 2) capable of generating electrical energy from the gradient of an acid-base conjugate pair. The electrical energy created from this ion gradient can be put to work powering a circuit which no longer needs an external power source to function within the body of an organism. All the energy is derived internally from the body's chemical energy. Oxyntic cells, being a type of epithelial cell, form cell-cell adhesions, which effectively divide each OCL compartment into two sub-compartments, which reduces the amount of neutralization between HCO.sub.3.sup.− and H.sup.+ that occurs within compartments. It is desirable for efficiency's sake that as much neutralization between conjugate acid-base pairs occur across Membrane Type 2 as possible, because only in this way can energy can be harvested to power a circuit. Note, the arrows in this diagram are used to denote the direction of flow of electrons through the circuit, with electrons traveling from the surface of Membrane Type 2 adjacent the region with a high concentration of HCO.sub.3.sup.−, into the wire with an arrow pointing towards the load, then into the wire with arrows pointing away from the load and to the surface of Membrane Type 2 adjacent to the region with a high concentration of H.sup.+. Though the wiring here is in parallel, simple, linear biological batteries can also be made by wiring cells in series as well. In fact, biological batteries can be wired in a combination of parallel and series to modify output voltage and current to suite specific applications.