Glass slide

Micropipettes

Starting Materials

Cut along dotted traces

Plexiglas square (1.1” x 1.1”)

0.2”

Interface reservoir sleevesDrummond 1-5-µL micropipette: OD = 0.042”Drill head = 0.046” (Lot#9923098)

Separation capillary sleeves (Outer capillary sleeves)Drummond microcap: OD = 0.034”Drill head = 0.037” (Lot#205309)

UV glue + UV lamp

Epoxy glue

365-µm OD capillary (Inner capillary sleeves)

A cross is formed in the Plexiglas square using the flat-head drills with the lathe machine. If you don’t know how to use the machine, ask for assistance from someone in the lab or one of the machinists.

Machining the Cross

Overhead view

Side view 1

Side view 2

0.046”

0.037”

0.037”

0.046”

Microcap sleevesM

icro

pip

ett

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leeves

Add a drop of UV glue to the outer ends of channels 1 and 3 and allow the glue to traverse down the channel. Be sure not to add too much glue.

Carefully place the microcap sleeves in the channels. At the same time, thread the 365-µm OD capillary through both sleeves to ensure alignment. These channels are used for the separation capillaries.

Observe the flow of glue under a microscope. Anneal when the UV glue reaches close to the center of the cross. Remove the 365-µm OD capillary.

Repeat the same procedure for channels 2 and 4 using the micropipette sleeves. These channels are used to connect the interface with a reservoir.

1

2

3

4

1

2

3

4

Place the glass square corner cut from the microscope slide on the center of the cross. This will be used to seal the interface. Add a small drop of UV glue to one corner of the glass square as shown above. Allow the glue to move to each edge through capillary action without leaking into the channels. Anneal when the glue fills the pink area. Repeat this step with all four corners.

1

2

3

4

Now the channels must be sealed with UV glue. Place some glue at the edge of the glass square where it meets with one of the channels. Capillary action will cause the glue to flow down the channel. Carefully watch the flow under a microscope and anneal just as the glue reaches the end of the channel. Repeat this step for the 3 remaining channels. At this point, the interface should be sealed except for flow within the sleeves.

1

2

3

4

The 365-µm OD capillary will be used as the inner capillary sleeve residing within the microcap outer capillary sleeves (channels 1 and3). First cut the capillary into two pieces having roughly 4-5-cm long. Remove the polyimide coat at the tip of each sleeve; insert this end into the outer sleeve while using epoxy glue on the outer surface area of the capillary sleeve. Do this for the other side as shown above. Give time to allow epoxy to dry.

The final step is to epoxy the separation capillaries within the inner capillary sleeves. The alignment must be done under a microscope. As the epoxy is drying, you can manually rotate the separation capillaries on each side to fine the best alignment but you only have 5 minutes or so.

With separation capillaries