Infrared Laser Analyte Detection via Selective Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting low vapor pressure analytes like explosives and chemical warfare agents are inefficient, often requiring physical contact, high power consumption, and can result in false alarms due to non-selective heating and signal clutter, especially when dealing with complex substrates like leather or food products.
Innovation Solution
A method using infrared light selectively tuned to specific absorption bands to heat analytes without decomposing them, allowing for non-contact detection by comparing IR detector signals before, during, and after excitation, which can be applied to both organic and inorganic analytes, using resonant infrared laser sources to maximize energy transfer and minimize substrate heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual swipe sampling is used to collect analyte particles, then particles can be transferred for analysis, but the process is impractical, time-consuming, and inhibits covert detection
Solution Approach 1:
The patent replaces manual mechanical swipe sampling with a laser-based optical system. The laser selectively heats and vaporizes analyte particles on surfaces, and the resulting vapor is detected by a sensor, eliminating the need for physical contact and manual particle transfer while enabling rapid, covert detection
Solution Approach 2:
The patent introduces laser-induced vapor as an intermediary between the solid analyte particles on surfaces and the detection system. The laser converts solid particles into vapor phase analyte, which can then be detected remotely without requiring physical collection or transfer of the original particles
2Reliability
If broad band IR sources are used for heating, then all incident material is heated, but this consumes much more power and increases background signal and false alarms
Solution Approach 1:
The patent uses a tunable laser source that can be selectively tuned to match the specific infrared absorption bands of the target analyte. This localized spectral targeting heats only the analyte molecules that absorb at the selected wavelength, minimizing power consumption and avoiding heating of substrate materials that would create background signal and false alarms
Solution Approach 2:
The patent changes the spectral parameter of the heating source from broad band to narrow band by tuning the laser wavelength to match the analyte's absorption characteristics. This parameter change enables selective heating that reduces power requirements and eliminates background interference from non-analyte materials
3Adaptability or versatility
If LIBS is used for detection, then any matter can be analyzed, but significantly higher power is required and the sample and surface are destroyed
Solution Approach 1:
The patent uses controlled, moderate laser heating that is sufficient to vaporize the analyte for detection but below the threshold that would cause decomposition or destruction of the sample. This partial action approach maintains the analyte in its original chemical form while enabling detection, unlike LIBS which uses excessive energy that destroys the sample
Solution Approach 2:
The patent utilizes the phase transition from solid/liquid analyte to vapor phase through controlled heating. The laser provides just enough energy to overcome the analyte's vaporization temperature without reaching decomposition temperatures, enabling non-destructive detection through vapor phase analysis
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 efficient, selective, and safe detection of analytes at stand-off distances with reduced power consumption, minimizing interference from substrates and providing high detection speed, zero interference with radar and communication systems, and the ability to detect a range of materials including explosives and chemical agents.
Implementation Method 1
an infrared laser source tuned to couple to an infrared absorption band of the analyte
Implementation Method 2
tuned to couple to an infrared absorption band of the analyte to maximize heating of the analyte
Implementation Method 3
determining whether the analyte is present by comparing emitted photons with an IR detector
Data Source
AI summary
A method for non-contact analyte detection by selectively exciting one or more analytes of interest using an IR source optionally operated to produce pulses of light and tuned to at least one specific absorption band without significantly decomposing organic analytes and determining if the analyte is present by comparing emitted photons with an IR detector signal collected one or more times before, during, or after, exciting the analyte. Another embodiment of the present invention provides a method for non-contact analyte detection by selectively exciting analytes of interest using one or more IR sources that are optionally operated to produce pulses of light and tuned to at least one specific wavelength without significantly decomposing organic analytes, wherein the analyte is excited sufficiently to increase the amount of analyte in the gas phase, and wherein the content of the gas is examined to detect the presence of the analyte.