On-Board Diagnostic Sensor for Respirator Breakthrough.

摘要

Nanomaterials Research has demonstrated the feasibility of developing an extremely sensitive, low temperature, low cost, and miniaturized chemiresistive sensor that can be mounted inside a respirator to warn users when toxic organic vapors are present inside the respirator. This sensor can alert the wearer when the respirator's filter cartridge is defective, when the respirator does not fit properly, or when the respirator has been compromised for any other reason. Current methods of predicting filter breakthrough are inexact and inefficient, so the development of a real-time, quantitative respirator sensor is an important achievement. The Nanomaterials Research VOC sensor is based upon novel materials selection (including polymers and nano-scale ceramic powders) which overcomes present limitations of solid state sensor technology including: high operating temperature (300-400DGC), significant power consumption (a result of the high operating temperature) and poor reproducibility from one sensor to the next. The development of new and unique polymer and ceramic composite materials for sensors has resulted in a sensor that is responsive to a wide range of toxic organic gases. If developed into a product, this sensor technology can result in dramatically increased levels of worker protection as well as significant cost savings because filter cartridges can be used more efficiently. During the Phase I feasibility study, prototype nano-composite sensors were prepared and packaged using a commercial electronics package. These sensors were fully characterized for their response to a variety of VOCs including toluene, propanol, tetrahydrofuran (THF) and methyl ethyl ketone (MEK). The sensors were tested under a variety of conditions, including varying humidity, oxygen and carbon dioxide levels. The sensor response was excellent throughout the testing. Planned improvements in fabrication and packaging will lead to a low-cost, reliable sensor that is capable of operating on approximately 30mW of power.