Dual dielectrophoresis controller and fluorescence analysis platform for capillary-driven microfluidics on a portable device
In this paper, we describe the components of a portable point-of-analysis (PoA) platform prototype. This prototype is capable of simultaneously controlling the operation of integrated electrodes in the microchannels of a capillary-driven microfluidics device, which is used to manipulate microbeads flowing with the fluid, detection and analysis of the fluorescence signal emitted by the labeled proteins captured on the microbeads surface. The microfluidic chip employs integrated planar metallic electrodes inside the microchannels for creating a highly localized non-uniform electric field, capable of manipulating and immobilizing polystyrene microbeads of diameter from 1 μm to 10 μm in the flowing fluid, via dielectrophoresis. The analysis platform integrates several modules responsible for energizing and controlling the electrodes in the chip, generating and detecting the fluorescence signal, processing and transforming the captured data, communicating and providing access to cloud storage through the smartphone and securely handling the chip in a dark chamber. A mobile device application manages the platform operation via Bluetooth and connects to a Cloud service for further data storage and analysis. We demonstrate the operation of the analysis device by measuring the fluorescence emission of functionalized 3 μm microbeads trapped via dielectrophoresis above the integrated electrodes as they reach a trapping equilibrium state.