Tag: fingerprint’

Halloween Invisible Ink and Sherlock Science

 - by KitchenPantryScientist

Write spooky messages for your friends with invisible ink! Just paint lemon juice on printer paper with a Q-Tip, let it dry and reveal the message using heat from a candle flame via oxidation!  Adult supervision is required when using candles. You can also reveal your message using a very hot light bulb, but we had better luck with a flame.

You can see how it looks in the segment below. We also dusted for fingerprints on glasses with chalk and cocoa powder to get ready for the Science Museum of Minnesota’s upcoming Sherlock exhibit.

Fingerprint Fun

 - by KitchenPantryScientist


For this project, I thought that it would be fun to mix a little science and a little art.  My sister told me that she heard you could make Valentine’s cards using fingerprints.  I’ve also heard that it’s pretty easy to lift fingerprints using scotch tape, so I thought we’d give it a try.  All you need for the science part is paper, scotch tape and a pencil.  For the valentines, you will need an ink pad, paper and markers. 

On www.wikieducator.org/Fabulous_Forensic_Fingerprints, I found a fingerprint-lifting technique that works well, even for very young children.  Simply take a pencil and scribble on a piece of paper until a small area is covered with the graphite from the pencil lead.  Have your child rub his or her finger around in the graphite until it is covered with gray.  Then, have your child carefully place their finger on the sticky side of a piece of scotch tape and carefully lift their finger off of the tape.  A clear fingerprint should be visible.  Place the tape face-down on another piece of paper to preserve the fingerprint. 



Your child can then inspect the fingerprint under a magnifying glass, or just with their naked eye.  If you go to the wiki website I mentioned, your child can decipher whether they think their fingerprint is a whorl, a loop, or an arch.  It is fun to have them trace their hand, fingerprint each finger and thumb, and tape their fingerprints to the appropriate fingers.  Your child’s fingerprints would be a great addition to their science notebook!  I’ve found that their notebooks are great keepsakes of their drawings and observations at different ages.  The kids had a lot of fun with this project and could do it unassisted once I showed them what to do.

For the Valentines, have your children put two fingerprints or thumbprints together in the shape of a heart.  Of course, they will also want to make fish, bugs, and who knows what else?  I gave my kids some ideas to get them started and they went from there!  (It’s fun to add details with markers.)   Have fun!