Chipless RFID Tags With Deformable Substrates
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Solution Overview
Problem
Radio-frequency identification (RFID) tags, especially passive ones, face challenges in cost competitiveness with other identification technologies and require innovative solutions to effectively track strain, angle, and displacement in applications like airframes and human performance monitoring.
Innovation Solution
Development of frequency-, phase-, and/or amplitude-shift encoded, chipless RFID tags with polarization-independent designs using conductive patches and slot resonators on deformable substrates, which alter electromagnetic signatures based on deformation, enabling efficient tracking of strain, angle, and displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive RFID tags use silicon chips connected to antennas, then they can store and transmit identification codes wirelessly, but the cost increases and competitiveness with optical barcodes decreases
Solution Approach 1:
The patent removes the expensive silicon chip from the RFID tag while maintaining the essential identification function. Instead of using a chip with memory and processing capabilities, the invention uses a passive electromagnetic structure that reflects radio waves to encode identification information, thereby eliminating the costly chip component while preserving wireless identification capability
Solution Approach 2:
The patent employs inexpensive passive electromagnetic structures instead of expensive active chips. These chipless tags use simple conductive patterns and resonant structures that can be manufactured at very low cost, making the tags economically competitive with optical barcode systems while still providing wireless identification functionality
2Reliability
If RFID tags are designed for standard identification, then they can retrieve identification codes, but they cannot effectively track strain, angle, displacement and other physical quantities
Solution Approach 1:
The patent designs RFID tags that simultaneously perform identification and physical quantity measurement functions. By incorporating deformable substrates and strain-sensitive electromagnetic structures, the same tag can both identify objects and track mechanical parameters such as strain, angle, and displacement, thereby achieving multi-functionality that bridges identification and sensing applications
Solution Approach 2:
The patent utilizes changes in electromagnetic parameters (frequency, phase, amplitude) of the reflected radio waves to encode both identification information and physical quantity data. When the substrate deforms or rotates, these physical changes modify the electromagnetic resonance characteristics of the tag, allowing the same structural modifications to serve dual purposes: maintaining identification while enabling physical quantity sensing
3Ease of manufacture
If RFID tags use fixed geometric patterns, then manufacturing is simple, but readability from different angles and directions is poor
Solution Approach 1:
The patent employs asymmetric electromagnetic structures and non-uniform conductive patterns that are specifically designed to compensate for angular variations. These asymmetric designs create electromagnetic field distributions that maintain consistent reflection characteristics regardless of the reader's angle relative to the tag, thereby improving readability from various directions while remaining manufacturable
4Ease of manufacture
If RFID tags are made with simple structures, then cost is reduced, but coding density and information capacity are limited
Solution Approach 1:
The patent divides the electromagnetic structure into multiple resonant elements and frequency components. By segmenting the conductive pattern into distinct resonant features at different frequencies, the tag can encode multiple bits of information through frequency-shift encoding, thereby increasing coding density without adding significant structural complexity or cost
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 cost-effective, flexible, and efficient means to track deformations and movements by altering electromagnetic signatures in response to substrate deformation, enhancing the readability of RFID tags from various angles and improving coding density.
Implementation Method 1
each of the one or more slot resonators reflects the electromagnetic wave at a specific identifiable frequency
Implementation Method 2
alteration of the shape of the substrate (e.g., by bending, stretching, folding, expanding, contracting, or otherwise deforming) modifies the shape, orientation, and/or pattern of the conductive material and/or slot resonators
Data Source
AI summary
The present invention relates to radio-frequency identification (RFID) tags that produce a unique radar signature by passive reflection of an electromagnetic signal. In particular, provided herein are frequency-, phase-, and/or amplitude-shift encoded RFID tags, and methods of use and manufacture thereof.