SBIR-STTR Award

Polymer Aging Concepts, Inc. proposes to develop a""Smart Shelf Life""(SSL) tag which provides a low cost health monitoring system for ordnance based on a new condition monitoring sensor technology called AgeAlert. The AgeAlert sensor in SSL labels comprises a conductive composite element made from a tiny portion of desensitized double base propellant and conductive fillers. The sensor responds to the tiny mass loss resulting from stabilizer depletion during aging by a resistance change in the sensor. SSL tags, integrating the AgeAlert sensor into a passive wireless transponder such as a passive Radio Frequency Identification (RFID) tag are bonded externally to the monitored ordnance item, ordnance casing or packaging so that the AgeAlert sensor""sees""the same thermal environment as the ordnance device propellant. No embedment of the sensor into the propellant is required, not are any electrical connections required to the ordnance device. A handheld wireless RFID reader provides electrical energy to the SSL tag, queries the sensor and calculates remaining life of the ordnance device by use of sensor-propellant correlation models developed by acceleration aging of sensors and propellant samples. The SSL tags will provide individual propellant aging data for ordnance reliability and service life extension programs.

This Phase II SBIR project will develop and field test a wireless "Smart Shelf Life" tag for ordnance which provides real time "go/no-go" status of propellant condition without special training or complex equipment. The tag integrates a new propellant health monitoring (PHM) sensor for nitrocellulose-based propellants developed in the Phase I effort and a passive wireless tag for monitoring the degradation of ordnance propellant. The tiny sensor is a surrogate of the propellant itself and is made of inert propellant components and conductive fillers so that it changes resistance as the propellant components age. Sensor resistance data obtained during accelerating aging allows correlation with propellant stabilizer depletion for selected propellants. The wireless tag, containing the PHM sensor is bonded externally to ordnance devices so that it "sees" a similar environment as the propellant. A wireless field reader queries the tag on the ordnance device and correlates sensor resistance with propellant aging data and displays remaining life of the propellant. Alternatively, PHM sensors are incorporated into environmental propellant health monitoring systems to provide objective propellant aging status for existing and proposed propellant health monitoring systems. Approved for Public Release 14-MDA-7739 (18 March 14).

Keywords:
Ordnance monitoring, propellant aging, propellant monitoring, degradation sensors, shelf life extension, aging models, smart labels, integrated vehicle health monitoring