New Strategies towards the Next Generation of Personal Worn Bio Detector

Although personal samplers have been used for many years in fields such as occupational hygiene to measure individual exposure to toxic materials [1], they are still not widely used by the military and civil defence agencies for detection of biological warfare agents (BWA). Due to the low toxic threshold and large dynamic range of the BWA concentration and field equipments’ high limit of detection, using personal samplers to inform whether soldiers or civilian personnel have been exposed to dangerous levels of BWA is particularly challenging.

Here, we present a new concept [2] for high concentration ratio sampling combining electrostatic precipitation of airborne particulates with electrowetting-on-dielectric (EWOD) droplet transportation. The concept is based on a lightweight personal electrostatic precipitator (ESP) to collect aerosol particulates onto a removable hydrophobic surface. The EWOD system then transfers the collected sample into a microlitre-size water droplet that is actuated across the surface [3] thus delivering a highly concentrated sample for analysis. For an optimised ESP-EWOD system, a concentration ratio of 4.4 × 10^5 per minute of sampling can be expected.

We will discuss the initial results obtained for each part of the concept separately and we will present the different strategies to move from two distinct units: a lightweight ESP and a transportable EWOD system, to a fully integrated, personal, worn bio-detector for detection of BWA on the military field.

References
[1] J. Vincent, Aerosol sampling, Wiley, Chichester, UK (2007).
[2] T. Foat, W. Sellors, M. Walker, P. Rachwal, J. Jones, D. Despeyroux, L. Coudron, I. Munro, D. McCluskey, C. Tan, M. Tracey, J Aerosol Sci, 95 43 (2016)
[3] M. Jonsson-Niedziolka, F. Lapierre, Y. Coffinier, S. J. Parry, F. Zoueshtiagh, T. Foat, V. Thomy and R. Boukherroub, Lab on a Chip, 11 490 (2011).