Advanced Personal Gas Detectors for Mining Applications: Final Report [Phase II] [2011]

Details

• Personal Author:
  Kostelecky CJ
• Description:
  During this SBIR Phase I project, Nanomaterials Research (NRLLC) successfully demonstrated a new type of sensor device for detecting hydrogen sulfide (H2S). This gas is extremely toxic at low concentrations, and workplace exposure is common in a number of industries. Improved sensors and gas detection instruments are sorely needed to ensure protection of these exposed workers and to reduce H2S emissions into the atmosphere, thereby affecting public health. NRLLC's new sensor device combines recent advances in both semiconductor materials and alternative sensor fabrication approaches. These novel components were produced using processes and architectures that are similar to those used in the manufacture of multilayer ceramic capacitors. The sensors had a footprint of only 0.45 cm x 0.30 cm and exhibited the requisite mechanical strength needed for handling and integration into traditional electronic packages. The sensors responded well to H2S at concentrations ranging from 5 to 50 ppm. These levels are commensurate with the monitoring requirements for workplace exposures, in which the personal exposure limit, or PEL, is 10 ppm and the short-term exposure limit, or STEL, is 15 ppm. The sensors exhibited a large decrease in resistance when the toxic gas was present, which is characteristic of n-type semiconductor behavior. This response was found to be linear with concentration and repeatable during multiple exposures. Response times (t50) were on the order of 20 seconds. Several variables were investigated to determine their effect on the sensor response and recovery. These included the composition of the sensor material, the operating temperature of the device, the particle size of the raw materials, the design of the multilayer structure, and the degree of porosity retained in the final device. While a more extensive study is required, the Phase I results suggest that the processing and operation of the devices can be optimized by controlling such variables, Synkera demonstrated ultra-low power combustible gas microsensors, based on our nano/microfabrication platform technology that integrates nanostructured sensing elements into a robust monolithic ceramic device. This sensor is aimed at enabling widespread protection of workers (miners, plant workers, first responders) because of it applicability in portable detection and the low cost, scaleable manufacturing routes used that will make it such protection affordable to a greater cross-section of potential users. A systematic development of the combustible gas microsensor technology was performed to meet the application requirements and advance the microsensor to a readiness level that enables integration with prototype instrumentation. The Phase II established a viable route to new combustible gas microsensors using AAO as the base material. The new sensors are highly sensitive, selective, and are robust and reliable. Through this development routes to commercialization and scale-up have been identified. One such route is the possible inclusion of this sensor under an effort funded by the Department of Homeland Security for the development of a multi-gas instrument for use by fire fighters. [Description provided by NIOSH]
• Subjects:
  Emergency Responders Manufacturing And Industrial Facilities Mining Occupational Health Personal Protective Equipment Safety
• Keywords:
  Detectors Factory Workers First Responders Gas Detectors Miners Mining Industry Nanofibers Nanomaterials Protective Equipment Sensors
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-88
• NIOSHTIC Number:
  nn:20058188
• NTIS Accession Number:
  PB2020-100158
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R44-OH-009026, 2011 Nov; :1-88
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Mining
• Performing Organization:
  Synkera Technologies, Inc., Longmont, Colorado
• Peer Reviewed:
  False
• Start Date:
  20070401
• End Date:
  20110831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3697a53d2d058685beaba1e77e01b2b952e536ac602850229d66447cb559c6d48782fd9fb4ad1fb75a561f8c52b9094451b4aa404c2b39896c52d6df44b7c432
• Download URL:
  https://stacks.cdc.gov/view/cdc/218939/cdc_218939_DS1.pdf
• File Type:
  [PDF - 3.74 MB ]