Automatic Design of Microfluidic Gradient Generators

Concentration gradient generators are common components of microfluidic devices when specified mixing ratios have to be acquired. However, depending on their complexity, the creation of a suitable design is an elaborate task. Although approaches exist that derive such a design, they suffer from low flexibility and usability, which is why most concentration gradient generators are still mainly designed manually thus far—a time-consuming and error-prone task. To tackle this problem, we propose a method for the automatic design of tree-shaped concentration gradient generators and introduce a publicly available online tool that automatically generates a suitable design by adjusting the hydrodynamic resistances within the network. Moreover, the proposed tool is not only able to generate designs complying with user-defined requirements, such as mixing ratios, flow rates, and channel widths but also works for any number of outlets. Simulations using a Computational Fluid Dynamics (CFD) tool as well as evaluations on fabricated designs confirm the quality of the results obtained by the proposed tool.