Design Automation for Microfluidics

The domain of microfluidic biochips is a multidisciplinary field which deals with the precise control and manipulation of fluids in the micro-scale. Corresponding biochips, often also known as "Lab-on-a-Chip" (LoC), are used to realize experiments or operations in domains such as medicine, (bio-)chemistry, biology, pharmacology, etc. The main idea is to realize assays, which are originally conducted in bulky and expensive laboratories, on a minimized, integrated, and automated single device.

However, the design and layout of microfluidic devices have become considerably complex tasks. Channels must be properly dimensioned and connected, the used samples and chemicals must be injected into the chip at the right pressure, and mixing, heating, or incubation processes must be initiated at the right time. This requires dedicated expertise on a huge number of physical parameters and, additionally, is mainly conducted by hand thus far. Moreover, the slightest changes in the assay easily render an already existing design useless and require a re-design of the device.

Our work aims to aid designers in these tasks by providing sophisticated methods for design automation and simulation. More precisly:

Design automation

In today's design and implementation of microfluidic devices, many steps are conducted manually thus far. Design automation can help here by providing designers with tools that accomplish such tasks in a push-button fashion. We develop corresponding tools out of which the following are also publicaly available (clicking on the links provide more details):

• Meander Designer: Designers frequently draw similar designs for meander channels in a CAD program like AutoCAD. In order to overcome this manual task, we developed this online tool, which allows to automatically generate meander designs with their needs and fabrication settings.

• Channel Router: This online-tool is able to generate a routing layout of channel-based microfluidic devices, where multiple components should be connected according to a specification. Furthermore, the tool also allows to prevent cornered channel bends by maintaining a minimal bending radius.

• Concentration Gradient Generator: This online-tool allows to automatically create designs for tree-shaped concentration gradient generators. Such devices are used to mix two fluids with different concentration values and provide various mixtures of these fluids (i.e., mixtures with certain concentration values) at corresponding outlets.

• Robustness Improvement: Manufacturing a given chip design always induces some kind of defects, since neither the used materials nor the used fabrication methods are perfect - frequently resulting in erroneous behavior of the chip. This tool allows to improve an existing design already in the design phase, so it becomes more robust against such defects.

Simulation

The state-of-the-art in the design of microfluidics is to fabricate the prototype, observe the functionality and refine the design until a working device is obtained. Of course, this is very expensive in terms of time and costs. We therefore propose to conduct simulations in order to validate the design before even the first prototype is fabricated. Therefore, our research focuses on methods for simulation, which are based on Computational Fluid Dynamics (CFD) and especially on the one dimensional (1D) analysis model (the hydrodynamic equivalent to electrical circuits). For the latter, we already have an openly accessible tool available:

• MMFT Droplet Simulator: This simulator exploits the 1D-model, which is especially suited for simulating designs before even the first prototype is fabricated and for design space explorations. Furthermore, it allows to simulate droplets and their respective paths inside a LoC with closed micro-channels.

More Information

Mainstream article introducing our FFG Project "Advanced Production of Microfluidic Devices through Simulation Methods"

Book (published by Springer) covering some of our methods

Munich Microfluidics Toolkit

Selected Papers

We developed several methods and tools which are specialized for the design of microfluidic devices. In the following, you can find a selected set of the resulting publications. A full list of papers is available at this page.

• Simulation and Design of Droplet Microfluidic Networks:
  • G. Fink, P. Ebner, M. Hamidovic, W. Haselmayr, and R. Wille. Accurate and Efficient Simulation of Microfluidic Networks. In Asia and South Pacific Design Automation Conference (ASP-DAC), 2021. PDF
  • G. Fink, A. Grimmer, M. Hamidovic, W. Haselmayr, and R. Wille. Robustness Analysis for Droplet-Based Microfluidic Networks. In IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems (TCAD), 2020. PDF
  • A. Grimmer, X. Chen, M. Hamidovic, W. Haselmayr, C. Ren, and R. Wille. Simulation before fabrication: a case study on the utilization of simulators for the design of droplet microfluidic networks. In RSC Advances, 8, 60:34733--34742, 2018. PDF (see also this page for the implementation and further information)
  • A. Grimmer, P. Frank, P. Ebner, S. Häfner, A. Richter, and R. Wille. Meander Designer: Automatically Generating Meander Channel Designs. In Micromachines, 9(12), 2018. PDF (see also this page for the tool and further information)
• Design of Droplet Microfluidic Networks exploiting a passive droplet routing mechanism:
  • G. Fink, M. Hamidovic, W. Haselmayr, and R. Wille. Automatic Design of Droplet-Based Microfluidic Ring Networks. In IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems (TCAD), 2020. PDF
  • G. Fink, M. Hamidovic, R. Wille, and W. Haselmayr. Passive Droplet Control in Two-Dimensional Microfluidic Networks. In IEEE Transactions on Molecular, Biological, and Multi-Scale Communications, 2020. PDF
  • A. Grimmer, W. Haselmayr, and R. Wille. Automated Dimensioning of Networked Labs-on-Chip. In IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems (TCAD), 2018. PDF
  • A. Grimmer, W. Haselmayr, A. Springer, and R. Wille. A Discrete Model for Networked Labs-on-Chip: Linking the Physical World to Design Automation. In Design Automation Conference (DAC), 50:1-50:6, 2017. PDF
  • A. Grimmer, W. Haselmayr, A. Springer, and R. Wille. Verification of Networked Labs-on-Chip Architectures. In Design, Automation and Test in Europe (DATE), 1679-1684, 2017.PDF
  • A. Grimmer, W. Haselmayr, and R. Wille. Automatic Droplet Sequence Generation for Microfluidic Networks with Passive Droplet Routing. In IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems (TCAD), 2018.PDF
• Design of Continuous Flow-based Microfluidics Using Valves (e.g. also PMDs):
  • A. Grimmer, B. Klepic, T.-Y. Ho, and R. Wille. Sound Valve-Control for Programmable Microfluidic Devices. In Asia and South Pacific Design Automation Conference (ASP-DAC), 2018. PDF (see also this page for the implementation).
  • A. Grimmer, Q. Wang, H. Yao, T.-Y. Ho, and R. Wille. Close-to-Optimal Placement and Routing for Continuous-Flow Microfluidic Biochips. In Asia and South Pacific Design Automation Conference (ASP-DAC), 530-535, 2017. PDF
• Design of EWOD & MEDA microfluidics
  • O. Keszöcze, Z. Li, A. Grimmer, R. Wille, K. Chakrabarty, and R. Drechsler. Exact Routing for Micro-Electrode-Dot-Array Digital Microfluidic Biochips. In Asia and South Pacific Design Automation Conference (ASP-DAC), 708-713, 2017. PDF
  • O. Keszöcze, R. Wille, T.-Y. Ho, and R. Drechsler. Exact One-pass Synthesis of Digital Microfluidic Biochips. In Design Automation Conference (DAC), 2014. PDF