STEM Activity: Invisible Ink

In the fascinating world of chemistry, there is often more than what meets the eye! Inventors use chemistry to create new materials, design products and solve everyday challenges.

You can explore the wonders of chemistry in a totally new way when you create an invisible piece of art, then reveal your masterpiece using everyday items you might already have at home. Watch as your blank canvas transforms into vibrant yellow and red hues in seconds! Will you make a portrait of a friend, draw a hidden treasure map or create an invention-themed picture? You decide!

Materials Needed

• Baking soda, 1 tablespoon
• Craft stick or spoon
• Drop cloth
• Hand sanitizer, 3 teaspoons
• Paintbrush
• Small bowls
• Turmeric, 1 teaspoon
• Water, 1 cup
• White paper

Step-by-Step Instructions

1. Cover your work surfaces with a drop cloth, as some of the materials could stain.
    
2. Create your invisible ink by mixing 1 tablespoon of baking soda with 1 cup of water in a bowl. Use a craft stick or spoon to stir the solution until the baking soda has fully dissolved.
    
3. Using white paper and a paintbrush, design your invisible artwork! As you create your design, keep in mind that areas where you use your invisible ink will turn red, and any areas without invisible ink will turn yellow.
    
4. When you’ve finished painting, set aside your invisible artwork and allow it to dry completely.
    
5. Create a transformation solution by combining 1 teaspoon of turmeric powder with 3 teaspoons of hand sanitizer in a separate bowl. Stir the solution well with a craft stick or spoon.
    
6. Ready to reveal your invisible artwork? Use the paintbrush to brush your transformation solution onto the paper and watch your artwork appear!

What Are We Discovering?

In this experiment, you used chemistry to create invisible ink and reveal it with a colorful chemical reaction. Did you notice the way the baking soda reacted with the turmeric and hand sanitizer in the transformation solution? Turmeric turns deep red or brown in alkaline conditions, such as when it is mixed with baking soda. The hand sanitizer suspends the turmeric and helps it dissolve. Curiosity and chemistry can turn everyday items like these into exciting inventions!

National Inventors Hall of Fame^® Inductee Herbert Henry Dow, founder of the Dow Chemical Co., was one of the creators of the modern American chemical industry. His inventions included steam and internal combustion engines, automatic furnace controls and water seals, but most of his inventions were chemical in nature. He is best known for his work in halogen chemistry, particularly the production of bromine and chlorine.

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