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Electroplating plus xerography process; using laser beam to control selective plating

Q. Hello,

I have a theory that I am going to test in a simple experiment. I wish to combine electroplating with the xerography process. My theory is that you can destroy electrical charge on a surface when you expose it to high intensity focused light. I wish to control where the electroplating process actually plates the cathode by using a focused high intensity image. The first phase will consist of a laser beam that focuses on a specific area of the cathode. I am hoping that the area exposed to the beam will not be plated. I have a home made power source that is capable of 4000 watts continually at 120 volts DC. The current can be monitored and controlled digitally by my laptop. Any suggestions on design or settings or even if it will work? Also, I will be using mostly copper and iron. Any suggestions on the easiest electrolyte solution to put together?

Scott Ketter
hobbyist - Nekoosa, Wisconsin, USA
March 25, 2009

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March 31, 2009

Q. Test results

The following is a summary of the test results from my most recent experiment in combining the xerography and electroplating processes.

Plating Recipe:
5 oz Distilled Water
5 oz Distilled White vinegar [in bulk on eBay or Amazon] (5% acidity)
1/4 Teaspoon Pure Salt
Ambient Temp = 72F
Ambient Light = 0 (Total Darkness)
Elapsed Time = 20 hours (approximately.)
Anode Material = Copper
Anode Connection = +746 VDC with the negative connected to ground.
Cathode Material = Ferrous Steel
Cathode Connection = Disconnected
Anode / Cathode Voltage Differential = 0.545 VDC

Setup:
I used a small jar with two stainless steel screws that suspended the anode and cathode materials in the solution. There was a small 5 mW laser that was focused on to the cathode. The anode was below the cathode in the solution approximately one inch. The cathode was a square inch steel plate with the laser target side facing up and the side closest to the cathode was facing down.

Results:
The bottom (anode) side of the cathode was plated very well with near perfect coverage and fantastic visual appearance. The top (laser) side of the cathode was not coated very well. The small area where the laser was focused did not have any coating at all. There was a discolored and slightly plated area around the focus point of the laser. The area near the edges of the top side was coated by copper but the coating wiped off very easily. I am not sure of the exact reason why the laser area was not coated. For now I can only speculate that the laser affected the ion flow over the top of the cathode and did not actually change the charge characteristics of the cathode its self. The gradient of coverage around the focus area could be due to the optical diffusion characteristics of the cathode material.

Future Experiments and Theories:
I believe that a high saturation of electrons in the plating bath will be more conducive to manipulation with focused light. My next experiment will consist of a thin sheet of aluminum foil that is suspended in the plating bath. I will use a higher voltage supply on the anode around 10,000 volts.

Scott Ketter
- Nekoosa, Wisconsin, USA