Solid Glucose Biofuel Cell Electrodes with Semipermeable Membranes

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Solution Overview

Problem

Existing glucose-oxygen biofuel cells require liquid mediums for electrodes, making them impractical for implantation in living beings and resulting in short lifetimes when using solid electrodes due to enzyme and redox mediator leakage.

Innovation Solution

Development of solid biofuel cells with anode and cathode electrodes formed from conductive materials mixed with enzymes and redox mediators, surrounded by semipermeable membranes that allow glucose and oxygen passage while blocking enzymes and redox mediators, using materials like graphite and conductive polymers, and manufacturing through compression of mixed powders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If liquid medium enclosures are used for electrodes, then the biofuel cell can properly operate with enzyme-catalyzed reactions, but it becomes impractical for implantation in living beings and difficult to handle

Engineering Contradiction:

Improveproper operation of biofuel cellVSAvoidimplantation feasibility and ease of handling

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the physical state parameter of the electrode system from liquid to solid. The electrodes are formed as solid agglomerates by mixing conductive material powder with enzyme and redox mediator, eliminating the need for liquid enclosures while maintaining electrochemical functionality

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates composite electrode materials by combining conductive material (graphite or conductive polymer powder) with enzyme and redox mediator in a solid matrix. This composite structure provides both electrical conductivity and biochemical catalysis in a solid, implantable form

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If solid electrodes are used in biofuel cells, then the device becomes easier to handle and implantable, but the lifetime becomes very short due to enzyme and redox mediator leakage

Engineering Contradiction:

Improveease of handling and implantationVSAvoidlifetime of biofuel cell

Core Design Contradiction:

Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The patent uses a semipermeable membrane (dialysis membrane) as a flexible thin film surrounding the solid electrode agglomerates. This membrane allows selective passage of small molecules (glucose, oxygen) while retaining larger molecules (enzymes, redox mediators), preventing leakage and extending device lifetime

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The semipermeable membrane acts as an intermediary barrier between the internal electrode composition and the external environment. It selectively mediates the transport of substrates and products while preventing loss of critical biochemical components

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables biofuel cells to be implanted in living beings with extended lifetimes and stable operation, as demonstrated by successful implantation in rats with sustained discharge currents from 10 to 50 microamperes over a 12-hour period.

Implementation Method 1

each of the anode and cathode electrodes is surrounded with a semipermeable membrane letting through oxygen and glucose and blocking the enzyme and the redox mediator

Methodology Applied

Scientific EffectSemipermeable membrane filtration: Semipermeable Membrane

Implementation Method 2

the anode comprises an enzyme capable of catalyzing the oxidation of the sugar

Methodology Applied

Scientific EffectEnzymatic catalysis: Enzyme

Implementation Method 3

catalyzing the oxidation of sugar

Methodology Applied

Scientific EffectOxidation reaction: Oxidation

Implementation Method 4

the cathode comprises an enzyme capable of catalyzing the reduction of oxygen

Methodology Applied

Scientific EffectEnzymatic catalysis: Enzyme

Implementation Method 5

catalyzing the reduction of oxygen

Methodology Applied

Scientific EffectReduction reaction: Reduction

Implementation Method 6

The redox mediator has a low redox potential enabling to exchange electrons with the anode enzyme

Methodology Applied

Scientific EffectRedox reaction: Redox Reactions

Data Source

PatentUS9017884B2Glucose biofuel cell

Publication Date: 2015.04.28 UNIVERSITE GRENOBLE ALPES

AI summary

A biofuel cell intended to be immersed into a liquid medium containing a sugar and oxygen, wherein the anode includes an enzyme capable of catalyzing the oxidation of the sugar and a redox mediator of low redox potential capable of exchanging electrons with the anode enzyme and the cathode includes an enzyme capable of catalyzing the reduction of oxygen and a redox mediator of high redox potential capable of exchanging electrons with the cathode enzyme. Each of the anode and cathode electrodes is formed of a solid agglomerate of a conductive material mixed with the appropriate enzyme and redox mediator and is solid with an electrode wire.