Improved Swab Design for Contact Sensing

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Project Description

Overview and Significance

This project is an important element of the overall ALERT strategy to enhance air travel security. Like project R2-D.1, it is focused on checkpoints by contact sampling of carry-on baggage. Existing methods for contact sampling use traps that are applied manually to extract explosives residue from suspicious bags. These traps are then placed in an ion mobility spectrometer (IMS), where any explosive residue is desorbed from the trap when the temperature is raised to roughly 250°C over a period of approximately 8 seconds. Commercial-off-the-shelf (COTS) traps are optimized to survive repeated exposure to the IMS desorber, but not to extract residue from the surfaces being interrogated. Considerable effort has been placed on finding ways to improve the sensitivity, accuracy, and response time of IMS tools. However, these efforts have been undertaken without a great deal of consideration of the essential first step in residue detection, which is extraction of the residue from the surface of interest. This project addresses directly this key step by pursuing rational trap design by optimizing trap properties leading to superior residue harvesting from surfaces. This effort involves several steps, including:

  • Investigating the mechanical properties of explosives residues and relating these properties to the effectiveness of residue removal from surfaces.
    • This effort was so substantial that it was split off to be a standalone project (R2-D.1).
  • Performing rational trap design
    • to optimize the effectiveness of traps at harvesting residue from surfaces.
    • To retain chemical and mechanical integrity at IMS operating temperatures
    • To interrogate substrates of interest effectively
    • To adhere to residues of explosives effectively
A great deal of attention has been placed on optimizing IMS protocols for detecting explosives residues in air travel security environments, yet little attention has been paid to the first step in IMS-based detection, which is contact sampling of residues using traps.
Phase 2 Year 2 Annual Report
Project Leader
  • Stephen P. Beaudoin
    Purdue University

Faculty and Staff Currently Involved in Project
  • Byran Boudouris
    Assistant Professor
    Purdue University

Students Currently Involved in Project
  • Melissa Sweat
    Purdue University
  • Darby Hoss
    Purdue University
  • Sean Fronczak
    Purdue University
  • Jennifer Laster
    Purdue University
  • Jordan Thrope
    Lafayette Jefferson High School