Passive RFID Temperature Integrity Sensor With Irreversible Exposure Record
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Solution Overview
Problem
Current RFID temperature sensors fail to monitor temperature variations continuously and reliably, leading to potential deterioration of sensitive products due to inadequate temperature control in the cold chain.
Innovation Solution
A temperature integrity sensor using passive RFID technology with Photochromic Torsional Switch (PTS) organic semiconductors that change conductivity based on temperature, allowing continuous monitoring and recording of temperature integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If passive RFID tags are used for temperature monitoring, then the device complexity and cost are reduced, but the ability to continuously monitor temperature variations is lost
Solution Approach 1:
The patent replaces traditional electronic temperature sensing components with organic semiconductor materials that directly modulate RFID signal properties in response to temperature changes. This substitution eliminates complex electronic circuitry while maintaining monitoring capability through the intrinsic temperature-dependent properties of the organic semiconductors.
Solution Approach 2:
The patent exploits changes in electrical conductivity and signal phase of organic semiconductor materials as temperature varies. By monitoring these parameter changes in the RFID signal, the system achieves continuous temperature monitoring without requiring complex sensing electronics, thus resolving the contradiction between simplicity and reliability.
2Use of energy by moving object
If traditional RFID tags measure temperature only at intervals, then energy consumption is reduced, but temperature variations between measurements are undetected
Solution Approach 1:
The patent enables continuous temperature monitoring by integrating temperature-sensitive organic semiconductor materials directly into the RFID tag structure. As the RFID tag continuously transmits and receives signals, the organic materials continuously modulate the signal properties according to the instantaneous temperature, providing uninterrupted temperature data without additional energy consumption from active sensing components.
Solution Approach 2:
The organic semiconductor materials inherently respond to temperature changes by modifying their electrical properties, which automatically modulates the RFID signal. This self-service mechanism eliminates the need for separate power-consuming temperature sensing and data logging electronics, achieving continuous monitoring with minimal energy usage.
3Reliability
If active RFID tags with batteries are used, then continuous monitoring capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces active electronic temperature sensing systems with passive organic semiconductor materials that inherently respond to temperature through changes in their molecular structure and electrical properties. This substitution eliminates batteries, complex circuitry, and signal processing electronics while maintaining continuous monitoring capability through passive signal modulation.
Solution Approach 2:
The patent creates a composite structure integrating organic semiconductor materials with RFID antenna elements. This composite approach allows the RFID tag itself to function as the temperature sensor, combining identification and temperature monitoring functions into a single passive device without requiring separate active sensing components.
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
Ensures reliable detection of temperature continuity and integrity, preventing product deterioration by providing irreversible records of temperature exposure, suitable for perishable products.
Implementation Method 1
The organic layer at the heterojunction (contact surface between the thin film and the metal of the RFID) acts as a signal 'modulator' of the device, varying some of the intrinsic physical properties of the RFID circuit, e.g. frequency, impedance (Z) and reflection coefficient (S11)
Implementation Method 2
A temperature integrity sensor using passive RFID technology with Photochromic Torsional Switch (PTS) organic semiconductors that change conductivity based on temperature
Data Source
AI summary
A temperature integrity sensor or more precisely a temperature continuity sensor of a product which needs to be kept at a temperature below its degradation temperature, is provided. The product includes a refrigerated or frozen edible product; a pharmaceutical product such as a vaccine, or an antibiotic; or a biological-medical product such as a sample of a body fluid or tissue, or an organ. The sensor is based on RFID technology, in particular passive RFID technology.