Issue 20, 2017

Image-based feedback and analysis system for digital microfluidics

Abstract

Digital microfluidics (DMF) is a technology that provides a means of manipulating nL–μL volumes of liquids on an array of electrodes. By applying an electric potential to an electrode, these discrete droplets can be controlled in parallel which can be transported, mixed, reacted, and analyzed. Typically, an automation system is interfaced with a DMF device that uses a standard set of basic instructions written by the user to execute droplet operations. Here, we present the first feedback method for DMF that relies on imaging techniques that will allow online detection of droplets without the need to reactivate all destination electrodes. Our system consists of integrating open-source electronics with a CMOS camera and a zoom lens for acquisition of the images that will be used to detect droplets on the device. We also created an algorithm that uses a Hough transform to detect a variety of droplet sizes and to detect singular droplet dispensing and movement failures on the device. As a first test, we applied this feedback system to test droplet movement for a variety of liquids used in cell-based assays and to optimize different feedback actuation schemes to improve droplet movement fidelity. We also applied our system to a colorimetric enzymatic assay to show that our system is capable of biological analysis. Overall, we believe that using our approach of integrating imaging and feedback for DMF can provide a platform for automating biological assays with analysis.

Graphical abstract: Image-based feedback and analysis system for digital microfluidics

Supplementary files

Article information

Article type
Paper
Submitted
04 Leq 2017
Accepted
29 Leq 2017
First published
05 Way 2017

Lab Chip, 2017,17, 3437-3446

Image-based feedback and analysis system for digital microfluidics

P. Q. N. Vo, M. C. Husser, F. Ahmadi, H. Sinha and S. C. C. Shih, Lab Chip, 2017, 17, 3437 DOI: 10.1039/C7LC00826K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements