Mechanical Details for Construction of a Dry Aerosol Deposition Device
Abstract
This document contains detailed design information for assembly of a Dry Aerosol Deposition Device (DADD). This report is further to technical report AFRL-RX-TY-TP-2008-4617, ADA492108 and technical report AFRL-RX-TY-TR-2008-4592, ADA502105; work unit DODT0056. Growing threats of biological contamination of infrastructure and equipment led to the development of antimicrobial surfaces/coatings. Standard methods to test efficacy of such materials have applied microbial agents suspended in aqueous buffers. These surfaces, however, will likely be contaminated via aerosol exposure, so antimicrobial efficacy measurements using microbes deposited as aerosols will provide a more-representative test platform. A settling chamber is the most common method for depositing biological aerosols on surfaces, but it can impose limitations in respect to time and variability of sample loading. In prior work, a Dry Aerosol Deposition Device (DADD) was developed that uses impaction rather than settling to load surfaces with biological aerosols, providing a mechanism for rapid and highly reproducible loading of microorganisms onto surfaces. The DADD was tested with Bacillus atrophaeus spores and Staphylococcus aureus vegetative cells, deposited to glass coupons at concentrations exceeding 1 104 colony-forming units/cm2. The average coefficient of variation (CV) for sample-to-sample loading within experiments was 13.6% for spores and 6.1% for S. aureus cells. The DADD provides a mechanism to load coupons with a highly reproducible challenge of microorganisms. Preliminary validation was performed on glass coupons, but the device can also be used with aluminum, concrete or fabric samples. The DADD was demonstrated to be a relatively simple and inexpensive device that can easily be contained within a 4-foot biological safety cabinet.1
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 22, 2014
- Accession Number
- ADA609647
Entities
People
- Robert Nichols
Organizations
- Universal Technology Corporation (United States)