LAUSR

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.