Uncoated Functional Paper for Flexible Electronics Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrates for printed/flexible hybrid electronics, such as PET films and microporous coated papers, suffer from poor durability, ink adhesion, and high production costs, and are not environmentally friendly, while multilayer coated papers are thick and less flexible.
Innovation Solution
Development of uncoated functional papers made from a slurry comprising 10 wt% to 90 wt% cellulosic fibers and 1% to 25% sizing solution, subjected to calendering at temperatures above 50°C, which are then printed with conductive inks to create flexible electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If PET films or microporous coated papers are used as substrates, then ink holdout is improved, but durability and ink adhesion deteriorate
Solution Approach 1:
The patent changes the physical and chemical parameters of the paper substrate by controlling fiber composition (10-90 wt% cellulosic fibers), sizing solution concentration (1-25%), and calendering temperature (>50°C) to achieve optimal balance between ink holdout, durability, and adhesion without requiring additional coating layers
Solution Approach 2:
The patent creates a composite paper structure combining cellulosic fibers with sizing agents applied during or after papermaking, forming a multi-component material that simultaneously provides ink absorption, durability, and adhesion properties
2Reliability
If additional processing steps are applied to improve ink adhesion, then ink adhesion is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies sizing treatment during the papermaking process or immediately after formation, before printing operations, to pre-establish ink adhesion properties. This preliminary action eliminates the need for subsequent adhesion-enhancing processing steps
Solution Approach 2:
The paper substrate is designed to inherently provide ink adhesion through its compositional structure and sizing treatment, making the substrate self-sufficient for printing applications without requiring additional auxiliary processing steps
3Quantity of substance
If multilayer coated papers are used, then ink holdout is improved, but flexibility and thickness deteriorate
Solution Approach 1:
The patent optimizes the basis weight and fiber composition parameters to produce a single-layer paper with adequate ink holdout capacity while maintaining thin profile and flexibility, avoiding the thickness penalty of multilayer constructions
4Productivity
If conventional substrates are used, then production is established, but environmental sustainability deteriorates
Solution Approach 1:
The patent employs disposable cellulosic paper substrates that are inexpensive to produce and readily biodegradable, replacing durable but environmentally persistent plastic films. The substrates are designed for single-use applications where sustainability outweighs long-term durability requirements
Solution Approach 2:
The patent changes the material composition parameter from petrochemical-based plastics to renewable cellulosic fibers, fundamentally altering the environmental profile of the substrate while maintaining compatibility with existing printing and processing infrastructure
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 functional papers exhibit improved durability, flexibility, and cost-effectiveness, with electrical resistance comparable to traditional films, and can be used in flexible hybrid electronics like circuits and sensors, offering a sustainable alternative to conventional substrates.
Implementation Method 1
The sizing solution can be applied during papermaking, applied in a size press or coater after the paper has been made
Implementation Method 2
The paper can be subjected to a calendering treatment at a temperature greater than 50° C.
Data Source
AI summary
Provided herein is an uncoated functional paper formed from a slurry comprising about 10 wt % to 90 wt % cellulosic fibers and about 1% to 25% sizing solution per total weight of the fibers. The sizing solution can be applied during papermaking and/or applied in a size press or coater. The paper can be calendered at a temperature greater than 50° C. Methods of making are also provided. Also provided are flexible electronics including a functional paper substrate printed with a conductive ink.