I posted this forum topic looking for ideas back in March, and Goodhart gave me the idea to use electrophotography. It didn't work in the limited timespan I had left in that semester, but I've improved upon the process a bit to generate these.
In the first step, I'll try my best to explain what exactly this is, however, it's going to be too long for an intro.
****OBLIGATORY SAFETY NOTICE****This Instructable involves the use of high voltages, where "high" means in the thousands of volts range. This should go without saying, but if you are not comfortable working with high voltage, you should not be attempting this, as you will most likely end up in a darkroom with only a safelight to see by, holding both leads of a HV power supply in one hand as you fiddle with your subject with the other. If you do something stupid, this amount of power is potentially deadly. I am not responsible for any damage to you or anything else.
Step 1: Now with added what?
As usual, the most succinct definition I can find is on Wikipedia. Essentially, Kirlian photography, or electrophotography, is a technique that creates an image on a light-sensitive medium (sheet film or photo paper) of the corona from an electrically charged object. I don't have any sheet film, so I used photographic paper, which also allows me to use a safelight.
If you simply Google "Kirlian photography," most of the pages are about how it's "taking pictures of auras" or some such nonsense. I will say this plain and simple: that is a load of bull. If they are images of an aura, then apparently quarters have souls. I highly doubt that.
There is depressingly little information out there on electrophotography, and no pictures. The three pages that I found were the aforementioned Wikipedia article, and article from Make magazine (thanks, Goodhart), and this page from Imagesco.com. To my knowledge, this is the only photographic tutorial on the internet-please prove me wrong in the comments if you know somewhere else.
What's in a name? I have been referring to the process as electrophotography, and the result as an electrophotogram. When the word is broken down to it's roots, it has the best description of the actual process. However, the term "electrophotography" is also used to refer to the process in a Xerox copy machine. This is not the same process. I also want to point out that this isn't quite true Kirlian photograhy-that requires much higher voltages than I have at the moment, and uses film, not paper.
Step 2: Supplies
-Power supply-I used a 2,000V power supply from All Electronics. This was just barely adequate for this purpose, so get a higher-voltage one. In my case I had to hook up a 12VDC 1A wall wart power supply, as it requires 12V input. Basically, you need something that will get you a decent-sized spark. (see image 2 below)
-Switch-No, you can't skip it. Figure out a way to turn it off.
-Metal discharge plate- Try to find a flat one, and not painted. The picture shows a steel plate from an old CD drive that I sanded the paint off of, however, I ended up using a sheet up aluminum.
-Photographic paper- No, not the inkjet paper from HP or Epson. I mean real black and white photo paper. I used Mitsubishi Gekko VC paper, but any paper will do.
-Darkroom-and the chemicals that go with it. You'll have to develop the paper eventually.
-Subject- The object that you are imaging. I've found that coins and keys make good subjects, as they conduct electricity, are flat, and have nice relief designs.
Step 3: Selecting your subject
I don't know what else makes good subjects, as I haven't yet tried anything else. I think that green leaves might work, and I might try my fingerprints if I can force myself to remain in contact with HV for that long. I'll be playing around with this all semester, so if I come up with other interesting subjects, I'll add them here. If I make any major breakthroughs, I may republish this.
Step 4: Basic setup
The first thing to do is to unplug the enlarger. If you have an older mechanical timer, there probably won't be an issue, but unplug it anyway. The power supply can transmit odd feedback loops through the power cord and turn on the timer, and therefore the enlarger, exposing your paper. I ruined two pictures before I thought to unplug the thing.
Next, determine which lead is which on your power supply. Hold both wires up to something attached to the ground, but not you--I used the counter that I was working on. One wire will do nothing, and the other will have small arcs jumping from the wires to the object. Remember which wire is which.
Now, lay your metal discharge plate down. I set it on the base of an enlarger because there is no empty counter space in my school's printing darkroom, and it made it easier to attach things. Connect the wire that did not arc to ground to the metal discharge plate. There is high voltage, but very low current, so you don't need heavy cables-I used some cheap dollar-store alligator jumper wires.
Finally, place your photographic paper on the discharge plate with the emulsion side facing up. Otherwise, the arc will be on the back of the paper, and you won't get as crisp lines.
Step 5: Creating the image
Place the coins, keys, or whatever else you decide to use on the photo paper. Keep in mind that the side in contact with the paper is what will be printed, and it will be a mirror image. After you have arranged your subject in some semblance of an artistic design, turn on the power supply, and briefly touch the free lead (the one that isn't attached to the discharge plate) to each item placed on the photo paper. If everything is working, you should see a blue glow coming from the underside of the subject. The length of time that you leave the power supply in contact with the subject will vary with the conductivity of the subject and paper, the rating of your power supply, the size of the subject, the diameter of your nostrils, and the alignment of Mercury and Neptune. In other words, experiment. Something less than a jiffy but longer than an instant was about right for me. A horrifically crappy video of the process is displayed below.
After you have zapped all of your subjects, turn off the power supply, slide out your paper, and develop it. Hopefully, you now have a really cool image of something on the paper. If it's too dark, zap it for less time, and if it's too light, zap it longer, just like you would printing a negative.
Step 6: Other notes and samples
A note on the images: While I'm publishing this under a AT-NC-SA license, which I realize allows you to use these images for any purpose as long as I get credit, they are still my artwork, and I ask that you treat them as such. If you want a high-res image without a giant watermark plastered across it, PM me.