Lab-on-a-Chip Platforms for Airborne Particulate Matter Applications: A Review of Current Perspectives

Abstract

Lab-on-a-Chip (LoC) devices are described as versatile, fast, accurate, and low-cost platforms for the handling, detection, characterization, and analysis of a wide range of suspended particles in water-based environments. However, for gas-based applications, particularly in atmospheric aerosols science, LoC platforms are rarely developed. This review summarizes emerging LoC devices for the classification, measurement, and identification of airborne particles, especially those known as Particulate Matter (PM), which are linked to increased morbidity and mortality levels from cardiovascular and respiratory diseases. For these devices, their operating principles and performance parameters are introduced and compared while highlighting their advantages and disadvantages. Discussing the current applications will allow us to identify challenges and determine future directions for developing more robust LoC devices to monitor and analyze airborne PM.

Keywords: Lab-on-a-Chip; airborne particulate matter; particle analysis; particle manipulation; particle monitoring.

Figure 1

Illustration of (a) the predicted fractional deposition of inhaled particles in the nasopharyngeal (blue), tracheobronchial (orange), and alveolar (green) regions of the human respiratory tract during nose breathing, and (b) airborne particle classification by the Equivalent Aerodynamic Diameter of PM₁₀ (blue), PM_2.5 (orange), and PM_0.1 (green) particles using a CI.

Figure 2

Schematic diagram of the inertial separation principle in a curved microchannel for airborne particle classification. (a) Particles mode radially outward in the curved channel due to centrifugal force after their alignment through the application of a sheath flow. (b) Dean vortices in a transverse view of the microchannel affecting particle movement.

Figure 3

Operation principles of the (a) Cascade Impactor (CI) and (b) Virtual Impactor (VI).

Figure 4

Design of a µIV. (a) CAD drawing of a µIV. (b) Collection efficiency curve of a μVI obtained by FEM analysis. Modified from Reference [84]. Copyright (2013) with permission from Elsevier. (c) Cross-section of a vertically stacked μVI. Modified from Reference [98]. Copyright (2019) with permission from Elsevier.

Figure 5

Active separation techniques of selected airborne particles. (a) Trajectories of particles under an nDEP force for aerial bacterial isolation. Reprinted with permission from [112]. Copyright (2009) American chemical Society. (b) FEM simulation of positive charged NP sampling efficiencie curves. Reproduced from [115]. Copyright (2020) Molecular Diversity Preservation International under a Creative Commons Attribution License available online: https://creativecommons.org/licenses/by/4.0/ (accessed on 14 February 2022).

Figure 6

Schematics of electrical sensors. (a) Surface Acoustic Wave or SAW. (b) Quartz Crystal Microbalance or QCM. (c) Film Bulk Acoustic Resonator or FBAR. (d) Piezoelectric Cantilever Resonator or PCR.

Figure 7

Schematics of electrical sensors. (a) Capacitive. (b) Corona discharge.

Figure 8

Continuous flow microfluidic techniques for the detection of PM in the air. (a) Responses of the O detector and the X detector to different gaseous analytes. Modified from Reference [185]. Copyright (2017) with permission from Elsevier. (b) Schematic diagram of a LAMP-based microfluidic device for airborne bacterial identification. Reprinted with permission from Reference [190]. Copyright (2014) American chemical Society. (c) Schematic diagram microfluidic/SERS analytical device. Modified from Reference [199]. Copyright (2007) National Academy of Sciences of the USA.

Figure 9

Schematic diagram of an electrowetting device for airborne PM analysis. Reproduced from Reference [166]. Copyright (2020) Molecular Diversity Preservation International under a Creative Commons Attribution License available online: https://creativecommons.org/licenses/by/4.0/ (accessed on 14 February 2022).

Figure 10

Paper-based microfluidic techniques for airborne PM detection. (a) Schematic diagram of a distance-based µPAD. Reprinted with permission from Reference [211]. Copyright (2015) American chemical Society. (b) Schematic diagram of a UAV-based approach for airborne particle sampling. Reprinted with permission from Reference [175]. Copyright (2019) American chemical Society. (c) Principle of operation of a mPAD. Reprinted from Reference [183] with permission from AIP Publishing.