5.3 Setup of Case Studies
69
Master Fabrication
A glass substrate (Borofloat 33, Schott AG, Mainz, Germany) with a thickness of
1.0 mm was cleaned with acetone, isopropanol, and deionized water. The substrate
was consecutively dried in a nitrogen stream. A dehydration bake at 200 ◦ C for
20 min was performed using a hot plate as all following baking steps. A single layer
of dry film resist (Ordyl SY355, Elga Europe, Nerviano, Italy) was laminated onto
the substrate followed by a soft-bake at 85 ◦ C for 3 min. The lamination process
and the soft bake were repeated for another layer. The substrate was exposed with
UV light through a polymer film mask (dark field) for 90 s. The post-exposure
bake (PEB) followed at 85 ◦ C for 60 min. The development was performed using
Ordyl developer and rinser (Ordyl Developer & Rinser, Elga Europe, Nerviano,
Italy). The substrate was developed first in the used developer for 4 min and then
in the fresh developer for 3 min. The development was discontinued with the
rinser bath for 2 min. The development was finished by rinsing the substrate with
isopropanol and deionized water. The process was completed with a hard bake at
120 ◦ C for 1.5 h.
Chip Fabrication
33.0 g of PDMS (Sylgard 184, Dow Corning, Midland, MI, USA) in a ratio of 10:1
was prepared and thoroughly mixed with an electric stirrer for 5 min. The compound
was de-gased in a vacuum chamber for 45 min. The PDMS was poured onto the
previously fabricated master mold creating a layer thickness of 4 mm. The PDMS
was cured in a convection oven at 60 ◦ C for 2.0 h. The chip was peeled off the master
mold and bonded via oxygen-plasma (at 50 W for 2 min) onto a glass substrate.
5.3.2 Setup for Realizing Dedicated Resistances
The first case study considers the realization of dedicated fluidic resistances.
Therefore, the Meander Designer was used to generate designs of meanders with
resistances ranging between 10 and 50 mbar/(μl/min), i.e. 10, 15, 20, 25, 30, 40,
and 50 mbar/(μl/min). As an example, for generating a meander with a resistance of
50 mbar/(μl/min), the specification and fabrication parameters as shown in Fig. 5.1
were set in the Meander Designer. The correspondingly generated output consisting
of the log and the generated meander is shown in Fig. 5.2.
Note that, when generating these meanders using the Meander Designer, the
variations resulting from the used fabrication process and how they affect the
resistances of the meanders were unknown. Therefore, no correction factor was
initially used in the Meander Designer.
For each fluidic resistance, four copies of the generated meander were fabricated.
Then, the volumetric flow rate through each of these meanders was measured.
69
Master Fabrication
A glass substrate (Borofloat 33, Schott AG, Mainz, Germany) with a thickness of
1.0 mm was cleaned with acetone, isopropanol, and deionized water. The substrate
was consecutively dried in a nitrogen stream. A dehydration bake at 200 ◦ C for
20 min was performed using a hot plate as all following baking steps. A single layer
of dry film resist (Ordyl SY355, Elga Europe, Nerviano, Italy) was laminated onto
the substrate followed by a soft-bake at 85 ◦ C for 3 min. The lamination process
and the soft bake were repeated for another layer. The substrate was exposed with
UV light through a polymer film mask (dark field) for 90 s. The post-exposure
bake (PEB) followed at 85 ◦ C for 60 min. The development was performed using
Ordyl developer and rinser (Ordyl Developer & Rinser, Elga Europe, Nerviano,
Italy). The substrate was developed first in the used developer for 4 min and then
in the fresh developer for 3 min. The development was discontinued with the
rinser bath for 2 min. The development was finished by rinsing the substrate with
isopropanol and deionized water. The process was completed with a hard bake at
120 ◦ C for 1.5 h.
Chip Fabrication
33.0 g of PDMS (Sylgard 184, Dow Corning, Midland, MI, USA) in a ratio of 10:1
was prepared and thoroughly mixed with an electric stirrer for 5 min. The compound
was de-gased in a vacuum chamber for 45 min. The PDMS was poured onto the
previously fabricated master mold creating a layer thickness of 4 mm. The PDMS
was cured in a convection oven at 60 ◦ C for 2.0 h. The chip was peeled off the master
mold and bonded via oxygen-plasma (at 50 W for 2 min) onto a glass substrate.
5.3.2 Setup for Realizing Dedicated Resistances
The first case study considers the realization of dedicated fluidic resistances.
Therefore, the Meander Designer was used to generate designs of meanders with
resistances ranging between 10 and 50 mbar/(μl/min), i.e. 10, 15, 20, 25, 30, 40,
and 50 mbar/(μl/min). As an example, for generating a meander with a resistance of
50 mbar/(μl/min), the specification and fabrication parameters as shown in Fig. 5.1
were set in the Meander Designer. The correspondingly generated output consisting
of the log and the generated meander is shown in Fig. 5.2.
Note that, when generating these meanders using the Meander Designer, the
variations resulting from the used fabrication process and how they affect the
resistances of the meanders were unknown. Therefore, no correction factor was
initially used in the Meander Designer.
For each fluidic resistance, four copies of the generated meander were fabricated.
Then, the volumetric flow rate through each of these meanders was measured.