Multi-Variable Detector for a Wearable, Direct-Reading Worker
VOC-Exposure Monitoring Instrument

Research Trainee: Chengyi Zhang, PhD, Postdoctoral Researcher, Department of Environmental Health Sciences at the University of Michigan

Faculty Sponsor: Edward T. Zellers, PhD, Professor of Environmental Health Sciences and Chemistry at the University of Michigan

Zhang

Chengyi Zhang, Postdoctoral Researcher

Zellers

Professor Zellers

Project Abstract

The accurate measurement of occupational exposures to toxic volatile organic compounds (VOC) is critical to protecting the health of large populations of workers, impacting directly the effectiveness of epidemiologic studies, regulatory compliance determinations, and general health surveillance efforts. This project concerned the further development of a recently invented nano-enabled, optical microsensor technology, called the micro-optofluidic ring resonator (µOFRR), and its integration into a recently developed (in-house) belt-mounted, microfabricated, gas chromatograph (μGC) prototype instrument to enhance the capability for near-real-time determinations of worker exposures to complex mixtures of volatile organic compounds (VOCs).


Bridging a critical gap between two other on-going projects, this research was intended to yield proof-of-principle results demonstrating:

  1. An unusually high degree of selectivity by the sensor by virtue of probing responses at multiple wavelengths.
  2. Enhanced sensitivity by virtue of improved optical interconnection techniques.
  3. Integration with our wearable μGC via a compact add-on detection module.
  4. Multi-VOC analyses.

The project succeeded in achieving some, but not all, of the goals set out. We generated results demonstrating:

  1. A high degree of diversity of optical VOC sensing with one of the MPN films tested.
  2. The successful implementation of an MPN-coated μOFRR as a GC detector providing highly sensitive VOC detection with compact laser sources.

We have created guidelines for operating MPN-μOFRRs as µGC detectors and have characterized such devices for on-going testing aimed at more definitively demonstrating the applicability of this technology to monitoring worker exposures to VOC mixtures in near-real-time. This work addresses several priorities and strategic goals defined by NIOSH.