1 Introduction
7
allows for an early detection of possible errors, which potentially reduces the
number of required prototyping iterations. Furthermore, the applied model and
the simulation framework provide the basis for many of the following design
methods. Simulation is covered in detail in Chap. 3 of this book.
• Dimensioning Droplet Microfluidic Networks: For the design of a droplet
microfluidic network, the specification of the used components (e.g., the
resistances of channels, the applied pressures of pumps, the used phases, etc.)
have to be determined—i.e., the microfluidic network needs to be dimensioned.
This specification has to ensure desired flow conditions so that, e.g., droplets flow
along intended paths. Here, a huge number of parameters have to be considered,
which all affect the flow through the microfluidic device and, hence, whether
experiments are correctly executed.
In order to support the designer in this task, this book presents methods for
validating a specification of a microfluidic network as well as for automatically
dimensioning a microfluidic network. These methods are covered in Chap. 4.
• Designing Meanders: In order to realize the specification of the microfluidic
network in a physical design (also called layout or mask), the shapes of the
channels and modules have to be drawn as a vector graphic. Therefore, designers
commonly use programs like AutoCAD, Solid Edge, or Inkscape. The resulting
physical design is afterwards used as input for the fabrication process.
In the current state of microfluidics where no (or not yet a) standardization
exists, it is hard or even impossible to fully automate this task. However, small
utility methods which generate parts of a design in an automatic way can already
be helpful for designers. Especially meander channels are a central and often reoccurring entity in droplet microfluidic networks. Moreover, meanders are not
only required for droplet microfluidic networks but also for pressure-driven and
paper-based platforms.
This book presents a method, which allows designers to automatically generate meander channels for their respective needs (i.e., resistances and fabrication
settings). Details on the method, which is distributed as an online tool, 2 are
described in Chap. 5.
Besides that, further methods for designing microfluidic networks based on a
dedicated droplet routing mechanism, namely passive droplet routing, are proposed
in Part III of this book. Passive droplet routing does not require any active
droplet sorting mechanism based on, e.g., valves or switches, but only exploits
the hydrodynamic effect that a droplet always enters the channel with the highest
volumetric flow rate [20, 37].
More precisely, a bifurcation as shown in Fig. 1.3 allows to passively route
droplets through different paths. Therefore, the different volumetric flow rates
(i.e., the amount of fluid which passes per time unit) in the successor channels
of a bifurcation are exploited (in Fig. 1.3 these successor channels are named c 1
2 The tool can be accessed at http://iic.jku.at/eda/research/meander_designer/.
7
allows for an early detection of possible errors, which potentially reduces the
number of required prototyping iterations. Furthermore, the applied model and
the simulation framework provide the basis for many of the following design
methods. Simulation is covered in detail in Chap. 3 of this book.
• Dimensioning Droplet Microfluidic Networks: For the design of a droplet
microfluidic network, the specification of the used components (e.g., the
resistances of channels, the applied pressures of pumps, the used phases, etc.)
have to be determined—i.e., the microfluidic network needs to be dimensioned.
This specification has to ensure desired flow conditions so that, e.g., droplets flow
along intended paths. Here, a huge number of parameters have to be considered,
which all affect the flow through the microfluidic device and, hence, whether
experiments are correctly executed.
In order to support the designer in this task, this book presents methods for
validating a specification of a microfluidic network as well as for automatically
dimensioning a microfluidic network. These methods are covered in Chap. 4.
• Designing Meanders: In order to realize the specification of the microfluidic
network in a physical design (also called layout or mask), the shapes of the
channels and modules have to be drawn as a vector graphic. Therefore, designers
commonly use programs like AutoCAD, Solid Edge, or Inkscape. The resulting
physical design is afterwards used as input for the fabrication process.
In the current state of microfluidics where no (or not yet a) standardization
exists, it is hard or even impossible to fully automate this task. However, small
utility methods which generate parts of a design in an automatic way can already
be helpful for designers. Especially meander channels are a central and often reoccurring entity in droplet microfluidic networks. Moreover, meanders are not
only required for droplet microfluidic networks but also for pressure-driven and
paper-based platforms.
This book presents a method, which allows designers to automatically generate meander channels for their respective needs (i.e., resistances and fabrication
settings). Details on the method, which is distributed as an online tool, 2 are
described in Chap. 5.
Besides that, further methods for designing microfluidic networks based on a
dedicated droplet routing mechanism, namely passive droplet routing, are proposed
in Part III of this book. Passive droplet routing does not require any active
droplet sorting mechanism based on, e.g., valves or switches, but only exploits
the hydrodynamic effect that a droplet always enters the channel with the highest
volumetric flow rate [20, 37].
More precisely, a bifurcation as shown in Fig. 1.3 allows to passively route
droplets through different paths. Therefore, the different volumetric flow rates
(i.e., the amount of fluid which passes per time unit) in the successor channels
of a bifurcation are exploited (in Fig. 1.3 these successor channels are named c 1
2 The tool can be accessed at http://iic.jku.at/eda/research/meander_designer/.