Conductive Polymer Adhesive with Catechol Sulfonate Moieties
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Solution Overview
Problem
Conventional electrically conductive adhesives face challenges such as high costs for conductive fillers, filler aggregation leading to open circuits, oxidation issues, and high curing temperatures of polymer matrices, while intrinsically conducting polymers like PEDOT:PSS have limitations in adhesion and stability.
Innovation Solution
Development of an electrically conductive material comprising an anionic polymer with terminal catechol and sulfonate moieties and a cationic poly(3,4-ethylenedioxythiophene) polymer, which includes polymethylmethacrylate or polyacrylic acid as the polymer backbone, with N-methacryloyl-3,4-dihydroxyl-L-phenylalanine and 3-sulfoalkyl methacrylate as terminal moieties, and the use of polar organic solvents like glycerol to enhance conductivity and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrically conductive adhesives use large amounts of conductive fillers to achieve electrical conductivity, then electrical conductivity is improved, but cost increases and filler aggregation occurs leading to open circuits
Solution Approach 1:
The patent changes the fundamental parameter of conductivity mechanism from filler-based conduction to intrinsically conducting polymer-based conduction. The ICP provides electrical conductivity through its conjugated pi-electron system along the polymer backbone, eliminating the need for high filler loads while maintaining reliable electrical performance
Solution Approach 2:
The patent creates a composite material system combining ICP with polymer matrix and optional filler particles. This composite approach allows the ICP to provide the primary conduction pathway while the polymer matrix provides structural support and adhesion, and fillers can be used in much smaller amounts as supplementary conductive elements rather than primary conductors
2Strength
If conventional ECAs use polymer matrices with high curing temperatures to achieve good adhesion, then adhesion strength is improved, but processing complexity and energy consumption increase
Solution Approach 1:
The patent changes the curing temperature parameter by selecting polymer matrices that cure at lower temperatures. The patent specifically mentions polymers that can be cured at temperatures below 150°C, and in some cases below 100°C, while still achieving adequate adhesion strength for electronic assembly applications
Solution Approach 2:
The patent uses surface treatment agents or primers as intermediaries between the polymer matrix and substrate to enhance adhesion at lower curing temperatures. These intermediaries improve interfacial bonding without requiring high thermal energy, enabling effective adhesion at reduced curing temperatures
3Reliability
If conventional ECAs use conductive fillers to achieve electrical conductivity, then conductivity is improved, but filler oxidation occurs reducing reliability
Solution Approach 1:
The patent changes the chemical composition parameter by replacing metal fillers with intrinsically conducting polymers that have inherent oxidation resistance. The conjugated polymer structure of ICPs provides stable electrical conductivity without the oxidation susceptibility that plagues metal fillers like silver or aluminum
Solution Approach 2:
The patent replaces expensive, oxidation-prone metal fillers with more stable polymer-based conductive materials that do not degrade through oxidation, improving long-term reliability and reducing maintenance requirements
4Reliability
If PEDOT:PSS is used as an intrinsically conducting polymer to achieve good conductivity and processability, then electrical conductivity and solution processability are improved, but adhesion to substrates deteriorates
Solution Approach 1:
The patent merges PEDOT:PSS with additional polymer components to create a multi-component system. This combination maintains the excellent conductivity and solution processability of PEDOT:PSS while adding adhesion-promoting polymers that provide strong bonding to substrates, thus resolving the adhesion deficiency of pure PEDOT:PSS
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 new material achieves improved electrical conductivity and adhesion comparable to or exceeding conventional ECAs, is non-toxic, flexible, and water-soluble, with stable conductivity and adhesion strength, suitable for various substrates including biological surfaces.
Implementation Method 1
A polar organic solvent effective for increasing an electrical conductivity of the electrically conductive material relative to the electrical conductivity of the electrically conductive material without the solvent may be included
Implementation Method 2
an anionic polymer having a polymer backbone, a plurality of terminal catechol moieties bonded to the polymer backbone
Implementation Method 3
a plurality of terminal sulfonate moieties bonded to the polymer backbone; and (b) a cationic polymer including poly(3,4-ethylenedioxythiophene)
Data Source
AI summary
An electrically conductive material includes an anionic polymer having a polymer backbone that is bonded to a plurality of terminal catechol moieties and a plurality of terminal sulfonate moieties. It also includes a cationic polymer including poly(3,4-ethylenedioxythiophene).