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# Graphite Sheets Ice Cutting Experiment

December 16, 2015

Sometimes objects have the ability to do things that you would never expect! Take a look at the graphite sheets that were included in Thermtest’s Thermal Science Education Kits. When you handle them, they don’t seem much different from a piece of paper. They bend easily, and are quite fragile. However, they have an amazing characteristic: extremely high thermal conductivity! Thermal conductivity is the ability to transfer heat, and graphite sheets can do this incredibly quickly. If you want to see this in action with your own eyes, a fun, easy way to do it is by using the graphite sheet to cut through an ice cube. Yes, that’s right, this thin strip can cut through a solid ice cube right in front of your eyes! Follow the steps below to see for yourself.

#### Experimental Protocol

Materials:

• Ice cube
• Graphite sheet

Procedure:

• Place the ice cube on a plate/tray
• Hold the graphite sheet so that as much of your hands are touching it as possible. The more your hands come in contact with the sheet, the more heat it is able to transfer to the ice cube.
• Start cutting through the ice cube with an edge of the graphite sheet, keep going until your ice cube is cut completely in two! For best results, keep the cutting edge taut.
• Please note that graphite sheets are quite brittle, so be patient. Trying to cut too quickly will result in the sheet ripping. You will also notice that the graphite sheet is going to get cold!

## How did it work?!

Many may wonder how such a seemingly flimsy graphite sheet is able to easily cut through an ice cube that strong knives would have difficulty cutting. The reason is the high thermal conductivity of the graphite. Graphite has one of the highest thermal conductivities of any material on the planet, and as a result is able to instantaneously transfer the heat from your hand to the ice cube. This means that the edge of the graphite in contact with the ice cube melts its way through the structure using your body heat that it is pulling from your hands.

Bonus:

Do you think that a graphite sheet the size of a piece of paper with many palms touching it would cut through ice faster than a graphite sheet strip?

Yes! The more heat available for the graphite to conduct, the more it will transfer to the ice.