NASA STTR 2007 Solicitation


PROPOSAL NUMBER: 07-1 T6.01-9878
RESEARCH SUBTOPIC TITLE: Wireless Surface Acoustic Wave (SAW) Sensor Arrays
PROPOSAL TITLE: Passive wireless SAW humidity sensors

NAME: Applied Sensor Research & Development Corporation NAME: Temple University
STREET: 1195 Baltimore-Annapolis Blvd., Unit #2 STREET: 1601 N. Broad Street
CITY: Arnold CITY: Philadelphia
STATE/ZIP: MD  21012 - 1815 STATE/ZIP: PA  19122 - 6099
PHONE: (410) 544-4664 PHONE: (215) 204-9696

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Leland P Solie
1195 Baltimore-Annapolis Blvd., Unit #2
Arnold, MD 21012 - 1815
(410) 544-4664

Expected Technology Readiness Level (TRL) upon completion of contract: 2 to 3

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
This proposal describes the preliminary development of passive wireless surface acoustic wave (SAW) based humidity sensors for NASA application to distributed humidity monitoring systems. SAW devices are a platform technology for passive wireless sensing of numerous possible measurands. SAW devices have been demonstrated as passive wireless temperature sensors in NASA contracts NNK04OA28C and NNK05OB31C, and as hydrogen sensors and cryogenic liquid level sensors under contracts NNK06OM24C and NNK06OM23C. ASR&D is currently developing these sensors and systems further under NASA Phase II STTR contracts NNK07EA38C and NNK07EA39C. The proposed humidity sensors will use individually coded SAW device structures combined with hygroscopic film elements to produce rapid, sensitive humidity sensors capable of wireless operation over the full range of relative humidity (0% to 100%). The Phase I research will utilize the results obtained in ASR&D's coded SAW sensor and wireless interrogation system research, and external research on SAW-based and nanofilm based humidity sensing techniques. The team will evaluate hygroscopic films previously investigated and novel nanostructured films, along with sensor device simulation, to determine which films are most likely to produce devices with desirable characteristics. Issues including formation of chemically selective films on piezoelectric substrates, optimization of this film, and the effects of environmental factors on device performance will be investigated. Successful completion of the proposed Phase I activities will establish the technical feasibility of producing the proposed humidity sensors, evaluate their potential performance capabilities in a range of operational environments, and define the additional work necessary to effect device implementation. Assuming the results of Phase I are positive, Phase II could result in the development of multiple uniquely identifiable, wirelessly interrogable, humidity sensors.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The primary NASA application for the proposed sensors would be in a wireless multisensor system for humidity detection. With uniquely identifiable passive wireless sensors, a system could use low cost sensors mounted at numerous locations to remotely detect humidity leaks in real time. This system could be useful, for example, when used with NASA's "Sensor Web" to monitor humidity in air and soil in remote locations such as Antartica. The demonstrated ability of SAW sensor devices to survive extreme temperatures (including cryogenic cold), combined with the anticipated ability of the proposed sensing films to withstand wider temperature ranges than traditional polymer sensing films, make the applicability of these sensors to extreme environment sensing likely. The completely passive (i.e. no batteries) nature of the proposed sensors, combined with wireless operation, make them ideally suited to applications in space exploration and aircraft, where battery replacement is difficult or impossible. The rad-hard nature of SAW devices, combined with their ability to survive thermal extremes, makes space a natural application environment. Of course, the effects of such an environment on the chemicals sensitive films will need to be characterized further in order to gain a clear understanding of the limits of applicability for this technology.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Potential commercial and non-NASA applications for the proposed humidity sensors abound. Numerous humidity sensing applications currently exist, and generate sales of over 8 million humidity sensors per year worldwide, with annual revenues exceeding $600 Million. The proposed sensor s will have a competitive advantage for any applications where the use of wireless, completely passive sensors is advantageous. For example, commercial building product manufacturers may find it desirable to incorporate passive humidity sensors with essentially unlimited lifetimes into construction elements to be used in "smart" buildings, to monitor water vapor intrusion into walls, around doors and windows, and even into concrete structures. Such monitoring could allow building owners to recognize leaks early, preventing harmful growth of mold and further damage due to water. Humidity detection is important within concrete, both during curing (to ensure the concrete reaches intended design strength) and after cure to monitor water intrusion that might lead to structural failure (due to freezing) or corrosion of support structures. ASR&D is currently developing a wireless concrete maturity monitoring system using passive wireless SAW temperature sensors, that would benefit from humidity sensors. Given the antiquated state of much of the infrastructure in the U.S., such sensors may find wide application for structural monitoring of both aging and newly rebuilt bridges, roads, and tunnels.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Airport Infrastructure and Safety
Sensor Webs/Distributed Sensors
Spaceport Infrastructure and Safety

Form Generated on 09-18-07 17:52