Dry Electrode Adhesive for Biosignal Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current biosignal monitoring electrodes face limitations in prolonged use due to drying out, skin irritation, and poor signal quality, with existing gel electrodes having high salt and water content leading to short-term measurements and adhesive issues.
Innovation Solution
An ionically conductive pressure-sensitive adhesive composition comprising a (meth)acrylate resin with a high content of hydroxyl groups and a non-toxic ionic liquid, which forms a dry film for long-term biosignal monitoring without skin irritation and maintaining signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gel electrodes with high salt and water content are used to achieve low impedance and good signal quality, then signal quality is improved, but the electrodes dry out over time and cannot be used for prolonged measurements
Solution Approach 1:
The patent changes the fundamental parameters of the electrode composition by replacing water-based gel with an ionic liquid-based adhesive. This parameter change (from aqueous to non-aqueous ionic liquid) allows the electrode to maintain low impedance and good signal quality without the water content that causes drying out, thereby extending measurement duration indefinitely.
Solution Approach 2:
The patent uses a composite material system combining ionic liquid with (meth)acrylate resin containing hydroxyl groups. This composite provides both the ionic conductivity needed for low impedance (replacing the salt-water gel function) and the adhesive properties for skin attachment, while eliminating the drying issue through the use of non-volatile ionic liquid.
2Measurement precision
If high salt concentration is used in gel electrodes to achieve low impedance, then signal quality is improved, but skin irritation occurs in many patients
Solution Approach 1:
The ionic liquid acts as an intermediary substance that provides ionic conductivity (replacing the salt function) without causing skin irritation. The (meth)acrylate resin with hydroxyl groups serves as another intermediary, providing adhesion and a biocompatible matrix that interfaces between the ionic liquid and skin, eliminating direct contact with irritating components.
Solution Approach 2:
The patent changes the chemical composition parameters by replacing inorganic salts in water with organic ionic liquids in a polymer matrix. This parameter change maintains the ionic conductivity function while eliminating the skin irritation caused by high salt concentrations and water content in traditional gel electrodes.
3Duration of action of moving object
If carbon black is used as conductive filler in pressure sensitive adhesive to eliminate water content, then drying out is prevented, but adhesion is lost and signal quality deteriorates
Solution Approach 1:
The patent replaces the mechanical/conductive filler approach (carbon black) with an ionic liquid-based conductive system. Instead of relying on carbon black particles for conductivity and accepting adhesion loss, the ionic liquid provides both ionic conductivity and maintains strong adhesion through its molecular interactions with the (meth)acrylate resin and skin.
Solution Approach 2:
The patent creates a composite material where ionic liquid is integrated with (meth)acrylate resin containing hydroxyl groups. This composite provides a triple function: ionic conductivity (replacing carbon black), strong adhesion (improving upon carbon black formulations), and prevention of drying out (through non-volatile ionic liquid), simultaneously resolving all three issues.
4Strength
If gel electrodes with high water content are used to maintain adhesion, then initial adhesion is good, but the electrodes dry out and signal quality decreases over time
Solution Approach 1:
The patent changes the volatile content parameter by replacing water (volatile) with ionic liquid (non-volatile) in the adhesive formulation. This parameter change allows the adhesive to maintain its adhesion properties through the hydroxyl-containing polymer matrix while eliminating the drying out problem that limits measurement duration in water-based gels.
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
The adhesive composition provides low impedance and excellent skin compatibility, allowing for extended biosignal monitoring without drying out or causing skin irritation, while maintaining signal quality and adhesion properties.
Implementation Method 1
an ionic liquid... providing ionic conductivity
Implementation Method 2
a (meth)acrylate resin comprising at least 10% of a (meth)acrylate monomer comprising OH-group (hydroxyl group)
Data Source
Figure 1~2
Figure 3a~3b
Figure 4~5
AI summary
The present invention relates to an electrode adhesive, which is an ionically conductive (meth)acrylate based pressure sensitive adhesive allowing prolongated biosignal monitoring times without skin irritation and loss of signal quality.