Printable Electrolyte Ink for Fast-Switching Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrolytes for printed electronics, particularly electrolyte-gated field-effect transistors (EGFETs), face challenges such as insufficient switching speed, humidity sensitivity, and the difficulty in using chemically cross-linked ion gels due to rigid gel structures and high temperature requirements, which hinder their practical application in ink-jet printing.
Innovation Solution
A chemical cross-linked electrolyte composition comprising a backbone polymer, a chemical cross-linker with maleic anhydride groups, and an ionic liquid, where the solvent content is high enough to inhibit immediate gelation, allowing for self-assembly during printing and subsequent evaporation, enabling ink-jet printability without additional synthesis steps or high-temperature treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemically cross-linked ion gels are used to improve stability and ionic conductivity, then the electrolyte performance is improved, but the gelation occurs before printing making it non-printable
Solution Approach 1:
The patent applies preliminary action by pre-synthesizing the cross-linker (polymer with maleic anhydride groups) and backbone polymer separately, then mixing them with solvent and ionic liquid just before printing. The chemical cross-linking is initiated only after deposition through solvent evaporation, ensuring the electrolyte remains printable while achieving cross-linked stability. This resolves the contradiction by separating the cross-linking initiation timing from the printing process.
2Reliability
If chemical cross-linking is performed to enhance mechanical properties and water resistance, then the electrolyte stability is improved, but additional synthesis steps and high temperature treatments are required
Solution Approach 1:
The patent merges multiple functions into a single process step. The chemical cross-linking, solvent evaporation, and gel formation are combined into one spontaneous self-assembly process that occurs after printing. The maleic anhydride groups react with moisture in the air or added water to initiate cross-linking, eliminating the need for separate high-temperature annealing or UV-curing steps. This resolves the contradiction by reducing process complexity while maintaining humidity insensitivity.
3Speed
If high ionic conductivity is achieved through strong EDL formation, then the switching speed is improved, but the electrolyte becomes sensitive to humidity
Solution Approach 1:
The patent uses a composite material system consisting of backbone polymer, cross-linker with maleic anhydride groups, ionic liquid, and solvent. The cross-linked polymer network provides structural stability and humidity resistance, while the ionic liquid maintains high ionic conductivity and fast switching speed. The synergistic combination of these components resolves the contradiction by decoupling the humidity sensitivity from the ionic conductivity function.
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 solution provides a stable, humidity-insensitive, and fast-switching electrolyte with enhanced gate-insulating properties and ionic conductivity, suitable for wide-range applications, including those with heat-sensitive substrates, and demonstrates effective performance even at low relative humidity.
Implementation Method 1
The simple mixing of a polymer comprising at least one maleic anhydride group and a polymer comprising at least one hydroxyl group lead to a gelation occurring by self-assembly
Implementation Method 2
This hydroxyl/anhydride reaction leads to a covalent binding and is the basis of the chemical cross-linked structure of the polymer
Implementation Method 3
This electric field enables conducting ions to migrate to the semiconductor/electrolyte interface and to form the electric double layer (EDL), generating high charge accumulation
Implementation Method 4
depositing the obtained ion gel ink on a substrate, whereby a deposited ion gel is obtained
Data Source
Figure 1(a)~1(e)
Figure 2(a)~2(e)
Figure 3(a)~3(d)
AI summary
The present invention provides a method for preparing an electrolyte for printed electronics as well as the electrolyte as such and its use in electrolyte-gating field effect transistors. The method comprises the following steps: a) providing a mixture (1) comprising at least one backbone polymer, at least one chemical cross-linker, at least one solvent, whereas the amount of the at least one solvent is higher or equal than 90% of the sum of the amount of the at least one backbone polymer and the amount of the at least one chemical crosslinker, b) adding at least one ionic liquid to get an ion gel ink (2), c) depositing the obtained ion gel ink (2) on a substrate (3), whereby a deposited ion gel (4) is obtained.