Subtractive Manufacturing of Microfluidic 3D Braid Mixers

Subtractive manufacturing using the thread template approach is an emerging technique for rapid prototyping of complex, true 3D microfluidic systems, offering advantages to photolithography in terms of process complexity, and achieving excellent structure fidelity compared to 3D printing and micro-milling. This paper explores subtractive manufacturing for novel high-performance microfluidic 3D braid mixers. The broad freedom of design with subtractive manufacturing, that is achievable with minimal process complexity is exploited to study the impact of design parameters of such braid mixers on mixing performance. The braid mixer is compared by computational fluid dynamics and experimentally with a number of existing mixer designs using colorimetric chemical reactions. The use of a braid mixer in a streamlined production of nanomaterials in a multistep procedure, shows highly competitive performance compared to other microfluidic designs and nanoparticle assembly methods.