C.4 Fluidics chamber

Figure C.4a shows the three layers of materials that have to be assembled in order to build a fluidics chamber. Using a laser engraver, 6 holes are made in the front coverslip, where the samples are introduced (and removed) into the chamber. The same laser engraver is used to make the channels in the nescofilm layer. A micropipette and two dispenser (or bearing) tubes are also sandwiched between the front coverslip and the nescofilm gasket.

Figure C.4b shows the sealed chamber after the nescofilm has been heated and melted at $ 119\,^{\circ}$C. A zoomed view of the central channel (red frame) shows the disposition of the inner tubes. The micropipette is oriented vertically. The bearing tubes connect the upper and lower channels with the central ones and they are oriented diagonally. The samples introduced in these channels reach the central one by flowing along the bearing tubes.

Figure C.4: Fluidics chamber. (a) Assembly. (b) Dimensions, final appearance of the chamber and zoomed region of the central channel.

Figure C.5 shows how the chamber is mounted in the black frame, which is moved by the $ xyz$-stage. The buffer is introduced into the central channel by means of a large syringe that pushes the buffer stored into the bottle. Two independent small syringes (blue needles) filled with the samples (beads and molecules) are connected to the upper and lower channels. The 3 channels are drained with the opposite holes and the wasted buffer and samples are stored in the trash bottle. The micropipette is connected to another syringe (red needle) filled with air, which is used to immobilize a bead at the tip of the micropipette by suction of air.

Figure C.5: Tubing of fluidics chamber. The samples flow from left to right.

JM Huguet 2014-02-12