By: Craig Barteaux And Kyle Stavish

Engineering 45 Fall 2010  Electroplating is a plating process in which metal ions in solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal. Electroplating is primarily used for depositing a layer of material to bestow a desired property (e.g., abrasion and wear resistance, corrosion protection, lubricity, aesthetic qualities, etc.) to a surface that otherwise lacks that property. Another application uses electroplating to build up thickness on undersized parts.

THE PROBLEM THE SOLUTION

 In order for the  We coated the surfaces electroplating process to of our organic samples work, we need a with two types of negative charge to be conductive materials. distributed across the  The first was a silver organic surface for the paint used primarily to Copper cations to be fix circuit boards. We attracted to. We need a dissolved the paint in conductive material that Acetone to thin it out. is non soluble, and will  The second was a adhere to the organic graphite Colloidal samples evenly. paint.

Watching Paint Dry – Literally!

 The solution was made using 100 g of CuSO4 (Copper Sulfate) and 25mL concentrated H2SO4 (Sulfuric Acid) in enough water to make .5 liters of solution. We then divided the solution into equal parts so we could do two electroplating at once. The initial setup (1.0) had narrow copper tubes, causing the cathode and anode to short out. For version 2.0, we used a sheet of copper and increased the diameter to match that of the container. We had much better results, although the process was still very slow. After 4.5 hours of running 225 mA of current at .22 V through our solution, we doubled the power supply on the acorn to 450 mA.

When the process which was used on the graphite covered bone we made an alarming discovery.

No copper was deposited on the graphite at all

The process was still ineffective even after we used a modified cell phone charger to increase the voltage to 18 V causing only deposits on the wire itself.  The cause became apparent when we placed an ohm meter on our sample and discovered that it no longer conducted electricity at all.  Oils had seeped out from the bone and disrupted the graphite  We applied a fresh coat and immediately after it was dry tested it again and found that it had resistance of ≈ 1000 Ω/in. Copper deposits start to spread from the wire connection to the end of the bone.  The silver is highly conductive and works much faster than the graphite counterpart however it is also somewhat soluble so some of the silver will flake off leaving a patchy finish. It is for this reason that we recommend the graphite as a base coat due to its greater durability.  The plating worked best on smooth surfaces.  Pointy things were slow to plate.

 Construction - create a weldable surface on wood, stone, etc.  Failure Detection – Conductivity would be compromised if the object cracks.  Preservation – Create a airtight shell to protect objects.  Medical – Broken bones could be welded, and prosthetics could be attached.  We would like to thank the following for their generous contributions to our project:

 Gregg Davis – S.R.J.C. Physics Lab Tech.  Wikipedia - www.wikipedia.org  Nick Anast – S.R.J.C. Anthropology Dept.  Chemistry Dept. S.R.J.C.  Peet‘s Coffee