Enhancement of mass and heat transfer using herringbone inspired microstructures for application in microfluidic redox flow cells

Abstract

Enhancing advection is of uttermost importance in many laminar microfluidic devices in order to thin boundary layers which limit both mass and heat transfer. We address this challenge by integrating herringbone-inspired flow promoters in channels for microfluidics. Due to the small dimensions of microchannels, microfluidic devices typically experience a purely laminar flow regime and are thus limited by diffusion. By augmenting diffusion limited transport to the wall of species and heat with advective transport mechanisms, the performance per unit area of microfluidic devices can be significantly improved. In the present contribution, we demonstrate that herringbone microstructures are a very promising class of flow promoters to passively increase both mass transfer in chemical reactions as well as heat transfer within the same device. This combined use of the same passive flow promoter microstructure is for example attractive for on-chip microfluidic redox flow cells for microprocessor power delivery with integrated cooling by using the same electrolyte as an energy carrier and as a coolant.