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Inspired by how the human eye detects millions of colors, researchers have developed an infrared (IR) standoff sensor that is ultra-low in size, weight, power, and cost and can detect and identify a broad array of chemical threats.
Protecting warfighters from chemical threats requires systems able to quickly detect and identify hazards, even in complex environments with many chemicals and changing conditions. IR standoff sensors detect threats from a distance by capturing the unique IR signals of chemicals. This provides a crucial distance between the chemical threat and warfighters, which gives them time to either avoid the contaminated area or to don the appropriate protective equipment.
The traditional IR standoff systems are costly, fragile, require extensive training to use, and consume a lot of power, making them less than ideal for field use. To address these issues, the Defense Threat Reduction Agency’s (DTRA) Chemical and Biological Technologies Department in its role as the Joint Science and Technology Office (JSTO) for Chemical and Biological Defense, an integral component of the Chemical and Biological Defense Program, partnered with researchers at the Naval Research Laboratory and the U.S. Army’s Chemical Biological Center (DEVCOM CBC) to create a new, biomimetic IR standoff sensor. This sensor weighs under 1.6 ounces, uses minimal power, and is more affordable.
Traditional IR standoff systems operate by using thermal contrast between chemical compounds of interest and the background of the cold sky to generate an infrared spectrum of the threat agent. These new IR sensors provide a solution for standoff chemical detection systems that are less expensive, bulky, and complex to augment the capability. The sensor works like the human eye, which uses different light-sensitive cones to distinguish millions of colors. Instead of visible light, this sensor uses overlapping IR filters to identify chemicals by analyzing their molecular vibrations. By applying statistical detection and machine learning, the sensor can distinguish between harmful chemicals like nerve agent simulants and harmless background (bkg) chemicals. This technology ensures accurate threat detection.
The biomimetic sensor uses multiple IR filter/detector combinations to generate a response to a target chemical in the same manner that the human eye sees different colors. The human eye uses three light-sensitive cones composed of different visible optical filters/dyes for discriminating over 2.3 million discernable visible colors from blue to red in the visible spectrum. The key element of the filters is that they are broadband and overlap. The International Commission on Illumination (CIE) chromaticity diagram describes how the eye perceives color over the visible spectral range. The biomimetic sensor uses the same mechanism as the eye to distinguish visible colors, however it operates in the IR portion of the electromagnetic spectrum, which provides molecular-level insight by probing bond vibrational modes. In the biomimetic sensor approach, three overlapping IR filters enable discrimination between different chemicals based on their IR spectral properties.
The DEVCOM CBC team used statistical detection algorithms and machine learning concepts to quantify the filter-conditional probabilities of detection and confusion between various threat and non-threat signatures, as well as to provide algorithms to predict the chemical identity. Machine learning results from this approach allow the biomimetic sensor to differentiate the chemical agent simulants dimethyl methylphosphonate (DMMP), diisopropyl methylphosphonate (DIMP), and methyl salicylate (MeS), as well as discriminate "threat" chemicals from common background interferents. Both methodologies demonstrate the inherent selectivity of the biomimetic sensor by modeling the system based on human color vision.
DTRA JSTO investment into the biomimetic sensor will ensure the capability for successful standoff detection of hazardous chemicals, such as nerve agents, for warfighters in the field. Because of its small size and weight and low power requirements, the sensor shows great promise for widespread applications throughout the Joint Force against chemical attack.
POC: Tyler Miller, tyler.c.miller23.civ@mail.mil
| Date Taken: | 10.28.2024 |
| Date Posted: | 10.28.2024 23:37 |
| Story ID: | 484105 |
| Location: | FT. BELVOIR, VIRGINIA, US |
| Web Views: | 486 |
| Downloads: | 0 |
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