Temperature Detecting Material for Tamper-Resistant Cold Chain Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature indicators lack absolute irreversibility, making them susceptible to tampering, and fail to detect both temperature increases and decreases effectively, which is critical for ensuring the integrity of perishable and pharmaceutical products during distribution.
Innovation Solution
A temperature detecting material that utilizes a combination of leuco dye, color developing agent, and decoloring agent with hysteresis characteristics, allowing for reversible color changes to detect temperature increases and decreases, and can be initialized by rapidly cooling to a control temperature, ensuring both upper and lower temperature limits are monitored.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a reversible temperature indicating material is used, then the indicator can be reused for normal temperature storage and transportation, but the indicator becomes susceptible to tampering and cannot guarantee temperature control integrity
Solution Approach 1:
The temperature indicating material is divided into two distinct functional components: a first temperature indicating material for detecting temperature increases (color development) and a second temperature indicating material for detecting temperature decreases (color disappearance). This segmentation allows each component to have optimized irreversible characteristics for its specific detection direction, preventing tampering while maintaining reusability for normal temperature conditions.
Solution Approach 2:
Different regions of the indicating material have different functional properties: the first indicating material region provides irreversible color development for upper temperature limit detection, while the second indicating material region provides irreversible color disappearance for lower temperature limit detection. This local differentiation enables simultaneous achievement of anti-tampering reliability and reusability.
2Reliability
If a temperature indicator detects only temperature increase, then the indicator can provide absolute irreversibility, but the indicator cannot detect temperature decrease
Solution Approach 1:
The temperature indicating material is designed to perform multiple functions: the first temperature indicating material detects temperature increases through irreversible color development, while the second temperature indicating material detects temperature decreases through irreversible color disappearance. This multi-functionality allows a single indicator system to monitor both upper and lower temperature limits, enhancing versatility while maintaining detection reliability.
3Reliability
If an irreversible temperature indicating material is used, then tampering is prevented, but the indicator cannot be initialized for reuse
Solution Approach 1:
The indicating material exhibits dynamic response characteristics: upon exposure to temperatures outside the control range, the material undergoes irreversible color changes that prevent tampering. However, when returned to the normal temperature control range, the material dynamically reverses its color state (the first material becomes colorless, the second material becomes colored), enabling automatic initialization and reuse without manual intervention.
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 reliable method to detect temperature excursions in both directions, preventing tampering and ensuring product integrity by returning to a decoloring state, enabling the reuse of indicators for normal temperature storage and transportation.
Implementation Method 1
a first temperature indicating material A which... turns to a non-crystalline state and is kept in a decoloring state when cooled down lower than the color developing temperature Ta1 in a temperature increase process
Implementation Method 2
changes its color irreversibly between crystalline and non-crystalline states or between phase-separated and non-phase-separated states
Implementation Method 3
a second temperature indicating material B which... turns to a liquid state and is kept in a decoloring state when cooled down after melting to lower than the color developing temperature Ta2
Implementation Method 4
the first temperature indicating material A and the second temperature indicating material B each contain a leuco dye, a color developing agent, and a decoloring agent, and have a hysteresis characteristic in their color density-temperature curves
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~4
AI summary
A temperature detecting material comprises a first material containing a first temperature indicating material (temperature indicating material A) and a second material containing a second temperature indicating material (for example, temperature indicating material B), wherein the first temperature indicating material and the second temperature indicating material contain a leuco dye, a color developing agent, and a decoloring agent, and have a hysteresis characteristic in their color density-temperature curves, wherein the first temperature indicating material has a color developing temperature (Ta1 (Ta1A)) in a temperature increase process lower than a decoloring temperature (Td1 (Td1A)) in the temperature increase process, and turns to a non-crystalline state and is kept in a decoloring state when cooled down below the color developing temperature (Ta1) in the temperature increase process with a predetermined cooling speed or more after melting, wherein the second temperature indicating material, a color developing temperature (Ta2 (Ta2B)) is lower than a decoloring temperature (Td2 (Td2B)) in the temperature increase process, and wherein the color developing temperature (Ta1) in the temperature increase process is lower than the decoloring temperature (Td2) in the temperature increase process and the color developing temperature (Ta2) is lower than the color developing temperature (Ta1) in the temperature increase process.