High-speed particle detection and tracking in microfluidic devices using event-based sensing. Issue 16 (23rd July 2020)

• Record Type: Journal Article
• Authors: Howell, Jessie; Hammarton, Tansy C.; Altmann, Yoann; Jimenez, Melanie
• Is Part Of: Lab on a chip. Volume 20:Issue 16(2020)
• Page Start: 3024
• Page End: 3035
• Publication Date: 2020-07-23
• Subjects: Miniature electronic equipment -- Periodicals; Combinatorial chemistry -- Periodicals; Biotechnology -- Periodicals; 543.0813
• DOI: 10.1039/d0lc00556h
• Languages: English
• ISSNs: 1473-0197

Abstract

Abstract : Event-based sensing offers unique advantages in terms of cost, sensitivity and compatibility with standard microscopes for high-throughput particle imaging in microfluidic systems. Abstract : Visualising fluids and particles within channels is a key element of microfluidic work. Current imaging methods for particle image velocimetry often require expensive high-speed cameras with powerful illuminating sources, thus potentially limiting accessibility. This study explores for the first time the potential of an event-based camera for particle and fluid behaviour characterisation in a microfluidic system. Event-based cameras have the unique capacity to detect light intensity changes asynchronously and to record spatial and temporal information with low latency, low power and high dynamic range. Event-based cameras could consequently be relevant for detecting light intensity changes due to moving particles, chemical reactions or intake of fluorescent dyes by cells to mention a few. As a proof-of-principle, event-based sensing was tested in this work to detect 1 μm and 10 μm diameter particles flowing in a microfluidic channel for average fluid velocities of up to 1.54 m s −1 . Importantly, experiments were performed by directly connecting the camera to a standard fluorescence microscope, only relying on the microscope arc lamp for illumination. We present a data processing strategy that allows particle detection and tracking in both bright-field and fluorescence imaging. Detection was achieved up to a fluid velocity of 1.54 m s −1 and tracking up to 0.4 m s −1 suggesting that event-based cameras could be a new paradigm shift in microscopic imaging.