Step 14: Final assembly
Locate the bottom piece of the lamp's exterior - it should be the only piece of acrylic that you haven't glued to something yet! Back in the dim history of step 2, we marked the outside of this piece. Position the piece so that the outside is down. Apply a generous amount of superglue to the copper side of the sensor plate and then fix the whole electronics stack to the center of the bottom piece.
It's important that the sensor makes the best contact possible with the plexiglass, as air between the sensor and the plastic will have an effect on its sensitivity to touch. It's best to press down firmly on all four corners of the sensor plate for about thirty seconds. At the end of this time, if one or more of the corners pops up when you let go, just apply a little more superglue and press down longer. If you have a pair of spring clamps, they make this part a lot less tedious.
Once the sensor is glued down, it's time to perform our final check of the lamp's functionality before sealing it up. Plug it in, watch the lights flash, and then prove that it's able to sense your hand's presence through the acrylic. Note that with the addition of the acrylic separating your hand and the sensor, it will appear much less sensitive than when you were touching the bare metal. The more skin contact you place on the sensor, the better. It should trigger with one or two knuckles, but it will definitely trigger if you give it your whole palm.
When you're satisfied that everything is still working fine, it's time for the ultimate step. Flip the unfinished box upside down, apply superglue in all the in-cut parts of the dovetail joint, and then put on the bottom plate. As you're putting on the bottom plate, there's a good chance that you'll have to much of the power cord pulled through the hole, so pull the slack back through as you bring the bottom plate closer. Once the bottom is on, apply 30 seconds of pressure to all four corners to get it good and set, and then you're done!