1 Get help from an adult to use the boxcutter to detach the the square bottom and top of the plastic food container. Once an adult makes the first slices, you can finish cutting it loose with scissors.
2 Use a circular item (like a tape roll or bottom of a coffee cup) to draw two circles on each of the plastic squares.
3 Draw your one-of-a-kind expressive emoji face on each of the plastic circles using whatever colored Sharpies you like.
4 Cut the faces away from the rest of the plastic and place them on a foil-covered baking sheet.
5 With the help of an adult, put the sheet in the oven for 2-3 minutes at 275 degrees. Watch the plastic shrink down to pin size!
6 After the pins have cooled, paint the side you did not draw the face on yellow to give it that emoji flare.
7 Add a drop of clear adhesive to the back to stick on your pin back.
8 Wear your emotions on your sleeve, shirt or backpack!
The Sci Behind the DIY
Not only will kids be able to personalize their pins, but they’ll discover why plastic containers shrink when put in the oven. The plastic containers—known scientifically as polystyrene—have polymers that all bunch together when exposed to heat, which causes the plastic itself to shrink. This happens when the containers are made, too, but they’re ironed out while they’re still hot and then quickly cooled down so they remain flat.
In the tech world, this shrinking process is extremely helpful to scientists, namely in nanotechnology. Scientists use nanotechnology to look at materials like glass and use these findings to help make solar cells and high-density displays. Sometimes that glass has patterns that scientists need to adjust. Printing glass with these patterns can take a long time and be very expensive, but using the same plastic used to make the emoji pins, scientists can print and shrink the patterns quickly and at a low cost. So, that pin your kid is proudly wearing to school is made from the same stuff that’s changing the way scientists do research.