Transparent Conformal Polymer Antennas for Flexible RFID

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Solution Overview

Problem

Existing transparent antennas are not optically transparent and do not reliably adhere to flexible substrates, limiting their application in non-traditional surfaces and materials, while conductive polymers have lower conductivity but offer advantages like low cost and ease of processing.

Innovation Solution

The development of an optically transparent conductive polymer antenna method using a conductive polymer material with surface tension between 0.028-0.060 N/m, applied through inkjet printing with ultrasonic vibration and dimethyl sulfoxide to increase conductivity, allowing for flexible and inflexible substrate attachment and high conductivity suitable for RFID and wireless communications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductive inks are used on inflexible substrates, then high conductivity is achieved, but optical transparency and flexibility are lost

Engineering Contradiction:

ImproveconductivityVSAvoidoptical transparency and flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the material parameter from traditional conductive inks to conductive polymers, which have different electrical and optical properties. This material substitution enables simultaneous achievement of flexibility, optical transparency, and adequate conductivity for RFID applications

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite conductive polymer materials that combine the benefits of flexibility, transparency, and conductivity in a single material system, eliminating the need to choose between conflicting properties

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If traditional subtractive fabrication techniques are used, then precise patterns are achieved, but material waste and substrate limitations increase

Engineering Contradiction:

Improvepattern precisionVSAvoidmaterial waste

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent inverts the fabrication approach from subtractive (removing material) to additive (depositing material). Inkjet printing deposits conductive polymer material only where needed, achieving precise patterns while minimizing material waste

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces mechanical subtractive processes (milling, etching) with a non-contact additive printing process, eliminating the need for material removal and enabling fabrication on flexible and non-traditional substrates

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If thick conductive polymer layers are used to achieve high conductivity, then conductivity improves, but optical transparency is reduced

Engineering Contradiction:

ImproveconductivityVSAvoidoptical transparency

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent optimizes the thickness parameter of the conductive polymer layer to achieve a balance between conductivity and optical transparency. By controlling layer thickness and using highly conductive polymer formulations, adequate RF performance is achieved while maintaining transparency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite conductive polymer materials with enhanced conductivity per unit thickness, allowing thinner layers to achieve the required electrical performance while maintaining optical transparency

Inventive Principle:

Principle #40Composite materials

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 enables the creation of reliable, optically transparent, and flexible antennas with high conductivity, suitable for various substrates, enhancing the efficiency and cost-effectiveness of RFID and wireless communication applications by making antennas smaller and less expensive.

Implementation Method 1

Ultrasonic vibration may be applied to the material to remove gases before the antenna design is printed

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

dimethyl sulfoxide may be added to the conductive polymer material to increase conductivity

Methodology Applied

Scientific EffectDoping: Dopants

Implementation Method 3

a surfactant may be added to the conductive polymer material to lower surface tension

Methodology Applied

Scientific EffectSurface tension reduction: Surfactant

Data Source

PatentUS8922435B2Transparent conformal polymer antennas for RFID and other wireless communications applications

Publication Date: 2014.12.30 DREXEL UNIV

AI summary

An optically transparent conformal polymer antenna and a method for producing the antenna from optically transparent conductive polymers. The method includes selecting an antenna design; providing an optically transparent conductive polymer material capable of being printed using an ink jet printer device; and printing layers of the polymer in the desired antenna design pattern onto a substrate. The surface tension of the polymer solution is adjusted to allow the material to pass through a printer head for printing on a flexible substrate. The material is modified to have a higher conductivity than regular conductive polymer materials so that a suitable antenna may be formed.