Fun with erasable pen, freezer and secrets...

When Sharko found the erasable gel pens in the science box today , we realized we haven't blogged it although we have been doing it for a couple of years now so here it is...

  The erasable pens we used here are 'Pilot Frixion erasable gel pens'. 

•  First take some paper to write
• Then take the erasable gel pen

•  Write whatever you want with the erasable pen on the paper.

• Then erase what you wrote with the eraser on the back of the pen

• Its so easy.  Now you cant see anything you wrote.

 

• Ask your mom or dad if they can get what you wrote back
• When they cant do it, take the paper and put it in the freezer for 10-15 mins
• Bring it out of the freezer 
• Magically whatever you wrote appears!!!  Its that easy...

Experiment done and written by - Sharko


How does this work?

Erasable gel pens are thermo-sensitive meaning their gel ink is heat sensitive.  When you 'erase' with the tip of the pen, the motion of erasing causes friction (maybe thats why they named those pens frixion) which produces heat and 'erase' the color.  The color doesn't get erased as much as it "disappears".  Since opposite of heat is cold, when we put the paper in the freezer, the 'cold' gets back the color.  You can erase it again and again and again:)



To test this theory, I took the paper which came out of the freezer with the drawing and text showing up again and applied heat to it.  I held it against water heater with hot water inside.  And presto! the color disappeared.  Then I put it in the freezer again and it came back to life again...












Happy experimenting...