Wearable sensor badge for toxic industrial chemicals
Inventors
Hur, Ryan • Palanisamy, Ramesh • Kim, Jeffrey • Chen, Gary • Li, Wei • Grudt, Dennis
Assignees
Publication Number
US-10330617-B2
Publication Date
2019-06-25
Expiration Date
2038-01-10
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Abstract
A wearable sensor badge utilizes a carbon nanotube (CNT) sensor array for selective sensing of chemicals from naturally diffused air or by sampling air using a pump/fan for higher sensitivity. An embedded microcontroller monitors the resistance of the sensing elements and by using an advanced detection algorithm the presence of TICs and/or CWAs are identified.
Core Innovation
The invention provides a wearable sensor badge capable of detecting toxic industrial chemicals (TICs) and chemical warfare agents (CWAs) in gas, vapor, and aerosol forms. This sensor badge employs a carbon nanotube (CNT) sensor array for selective chemical sensing from naturally diffused air or by actively sampling air with a pump/fan for higher sensitivity. An embedded microcontroller monitors the resistance changes of the sensing elements and uses an advanced detection algorithm to identify the presence of TICs and/or CWAs below permissible exposure limits (PEL) and immediately dangerous to life or health (IDLH) levels.
The background problem addressed is the impracticality of fixed sensor installations for ensuring chemical exposure safety for each individual in various environments such as manufacturing facilities or combat zones. Existing CNT-based sensors are effective for chemical detection but lack the portability and disposability needed for individual use. Therefore, there is a need for a lightweight, inexpensive, wearable sensor that can be easily carried by workers or soldiers, enabling continuous personal monitoring and timely alarms upon detection of dangerous chemicals.
The invention solves this problem by integrating a CNT sensor array with a microcontroller and air sampling mechanism in a compact, wearable housing. The sensor array elements are chemically functionalized for selective adsorption of target chemicals, producing characteristic signal patterns that differentiate TICs and CWAs from interferences through analysis of adsorption kinetics. The device includes multiple alarm indicators (visual, audible, tactile) and can communicate alarms remotely via a Wi-Fi module. It can be powered by a rechargeable or replaceable battery, optionally charged via USB, allowing independent operation and compatibility as a subsystem to other sensor systems.
Claims Coverage
The patent includes two independent claims encompassing features of the wearable sensor unit. The main inventive features relate to the sensor unit's structural configuration, sensor array composition, air sampling system, and detection and alarm functionalities.
Wearable sensor unit structure with integrated components
A sensor housing sized and configured for mounting on a person or personal protective equipment containing at least one air aperture, a power supply, a microcontroller, a sensor array of carbon nanotube sensors, an air pump creating airflow past the sensor array, and an air flow channel that is substantially isolated from the microcontroller.
Microcontroller monitoring of sensor array for toxic chemical detection and alarm activation
The microcontroller is configured to monitor the carbon nanotube sensor array for toxic chemicals and actuate an alert when detection occurs. It also determines gas concentration and compares sensor values to predetermined permissible exposure levels or time weighted averages.
Sensor array composition and mounting configurations
The sensor array comprises a plurality of carbon nanotube sensors, each functionalized with specific chemical groups for selective adsorption (such as carboxylic acid, octadecylamine, and others). The sensor array can be user removable and vertically mounted, with the air pump oriented perpendicularly, or non-removable and mounted horizontally adjacent to a horizontally mounted air pump.
Detection range and chemical specificity
The sensor array and microcontroller are configured to detect multiple toxic industrial chemicals and chemical warfare agents, including ammonia, hydrogen sulfide, sulfur dioxide, chlorine, carbon monoxide, nitrogen dioxide, nitric oxide, hydrogen cyanide, phosphine, methyl bromide, and nerve agents such as GA (tabun), GB (sarin), HD (sulfur mustard), VX.
Physical and functional characteristics of the wearable unit
The sensor housing dimensions range approximately from 3.6×2×1 inches (55 g) to 2.25×1.75×0.75 inches (30 g), include indicator lights on the exterior, and may be disposable when contaminated after an alarm event. The air apertures are positioned to facilitate air flow via the pump.
The independent claims broadly cover a wearable sensor unit with an integrated, functionally specified CNT sensor array and air sampling system managed by a microcontroller for selective, real-time detection of a range of toxic chemicals and chemical warfare agents, coupled with user alert features and tailored mounting and physical configurations.
Stated Advantages
Provides a small, lightweight, and inexpensive wearable sensor for continuous, personal monitoring of toxic industrial chemicals and chemical warfare agents.
Operates below permissible exposure limits and immediately dangerous to life or health levels, enabling early detection.
Selective chemical sensing through chemically functionalized carbon nanotube sensor arrays that produce characteristic response patterns to eliminate cross-sensitivity.
Multiple alarm indicators (visual, audible, tactile) and remote alarm communication capability for user notification and facility-wide alerts.
Versatility to be worn on various personal protective equipment and disposability after contamination.
Low power consumption with rechargeable or replaceable battery options, facilitating independent operation or subsystem integration.
Documented Applications
Detection of toxic industrial chemicals in industrial and manufacturing environments.
Monitoring chemical exposure for law enforcement and anti-terrorist personnel.
Environmental and agricultural contamination monitoring.
Personal protection for first responders, military personnel, and industrial workers.
Detection of chemical warfare agents in combat zones or tactical situations.
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