Passive Chronometric Tamper Indicator Using Chemical Diffusion
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Solution Overview
Problem
Current passive tamper-indicating devices (TIDs) lack the ability to provide a timestamp of tampering, making it impossible to determine the exact time of unauthorized access if the seal is breached between application and inspection.
Innovation Solution
A passive TID utilizing a chemical chronometer based on the diffusion of penetrants along fibers, with activation mechanisms triggered by tampering events, providing overt or covert indications of the time since application or intrusion through color changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If current passive TIDs are used, then the device provides unambiguous evidence of tampering, but the device cannot provide a timestamp of when the tampering occurred
Solution Approach 1:
The patent introduces a chemical intermediary (diffusing substance) that mediates between the tamper event and the time indication. The chemical diffuses through a medium at a known rate, creating a physical record of elapsed time that can be read without power sources or complex electronics, thus adding timestamp capability while maintaining passive device simplicity
Solution Approach 2:
The patent utilizes changes in physical parameters (diffusion distance, concentration gradients) of a chemical substance over time to encode temporal information. By measuring the extent of diffusion, the system determines elapsed time without requiring active components, resolving the contradiction between information richness and device complexity
2Measurement precision
If a chemical timer is added to provide timestamp information, then the ability to determine time of tampering is improved, but the device complexity increases
Solution Approach 1:
The patent employs a disposable chemical diffusion system where a sealed reservoir breaks upon tampering, releasing a chemical that diffuses through a medium. This single-use chemical mechanism provides precise time measurement without requiring reusable, complex, or powered components, achieving high measurement precision with minimal device complexity
Solution Approach 2:
The patent replaces potential mechanical or electronic timing mechanisms with a chemical diffusion process. The diffusion rate, governed by Fick's laws, provides a natural timebase that eliminates the need for clocks, batteries, or moving parts, achieving precise time measurement while keeping the device structure simple and passive
3Object-generated harmful factors
If the penetrant is colorless until excited, then covert reporting is achieved, but the ability to detect tampering without external stimuli is reduced
Solution Approach 1:
The patent applies different optical properties to different regions of the device. The penetrant chamber contains a colorless substance for covert operation, while the diffusion medium or reading window may contain indicators that become visible upon diffusion. This local differentiation allows the device to maintain covert properties where needed while providing detectability through controlled revelation
Solution Approach 2:
The patent utilizes the time-dependent nature of diffusion to create periodic or staged revelation. Initially colorless, the penetrant gradually diffuses and becomes visible over time, allowing the device to transition from covert to overt state in a controlled manner, balancing undetectability with eventual detectability
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
Enables precise determination of the time of tampering by calculating diffusion time based on known mass transport properties, offering both overt and covert reporting options.
Implementation Method 1
a penetrant chamber adapted to contain a penetrant material that selectively diffuses into the elongate structure at a predetermined rate when the release mechanism is actuated
Data Source
AI summary
A tamper-indicating device, the tamper-indicating device including: an elongate structure; a penetrant chamber coupled to the elongate structure; and a physical barrier (or other release mechanism) disposed between the elongate structure and the penetrant chamber; wherein the penetrant chamber is adapted to contain a penetrant material that selectively diffuses into the elongate structure at a predetermined rate when the physical barrier is ruptured (or the other release mechanism is actuated) by a tamper or environmental event; and wherein the penetrant material creates an overt or covert indication of the degree of diffusion into the elongate structure, the degree of diffusion indicating an amount of time since the tamper or environmental event. The tamper-indicating device further includes a substrate coupled to the elongate structure. Optionally, the tamper-indicating device further includes a visible time scale disposed on the substrate substantially adjacent to the elongate structure.