The microfluidic discs are created using layers of poly(methyl methacrylate)
(PMMA) bonded together by layers of pressure sensitive adhesive (PSA). Each
layer contains a structural component which is created by cutting voids out of the
material, when layered together this creates a three-dimensional network of cham-
bers and channels for flow control.
Once the disk design is complete it is important to ensure that all complex
structures requiring the interconnection of multiple layers are perfectly aligned, this
can be done by zooming and rotating around the central axis of the disc. If the
quality of the design is assured the disk design can be separated into 2D layers
which are compatible with the knife cutter and laser cutter (Fig.5.14).
Fig. 5.13 A cross sectional profile of the Lab-on-a-disk shows the location of each as well as the
intended material the designs will be cut from. The thinblue linesin the image above represent
layers of PSA whereas the large blue segments represent layers of PSA. The route between two
chambers is depicted by the black voids with the fluid (orange) moving outward due to the
centrifugal force
Fig. 5.14 Example SolidWorks design
134 B. Henderson et al.