Coupling electrohydrodynamics with photopolymerization for microfluidics-based generation of polyethylene glycol diacrylate (PEGDA) microparticles and hydrogels

Microfluidics-based methods have emerged as promising routes to generation of microparticles and hydrogels due to the precise control they provide. In this work, we use a microfluidic platform to couple electrohydrodynamics with photopolymerization for generation of polyethylene glycol diacrylate (PEGDA) microparticles and hydrogels. We employ a 3D hybrid glass-PDMS (Polydimethylsiloxane) microfluidic device to first generate PEGDA and PEGDA-water monomer droplets in the presence of electric fields and subsequently solidify them into microparticles and hydrogels through UV irradiation. Application of electric fields provides additional control over the size of the generated entities. Through the use of optical imaging, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy, we investigate the effect of the coupling strategy employed here on the size, uniformity, and morphology of the generated entities. We demonstrate that using a combination of varying outer flow rates, applied voltages, and monomer concentrations, one can tune the PEGDA particle and hydrogel sizes ranging over an order of magnitude while maintaining high monodispersity. In addition to expanding the spectrum of operating parameters, the current approach, through the application of electric fields inside a 3D hybrid microfluidic device, has additional advantages over existing techniques in terms of easy device fabrication, continuous operation without clogging, and uniform size distribution.