Brains On! Science Podcast for Kids

Episode: How do stickers stick?
Host: Molly Bloom
Kid Co-host: Amira from Indianapolis
Date: January 27, 2026

Overview

This episode explores a sticky topic: the science behind how stickers actually stick! Host Molly Bloom and kid co-host Amira take listeners on a deep dive into adhesives, zoom in on molecules with a pretend “Zoomray,” chat about not-so-obvious stickers (like those inside juice boxes!), and meet an expert working on new, eco-friendly and even medical-grade stickers. The show keeps its signature playful tone, with sound experiments, creative sticker ideas, funny tangents, and a bit of science magic.

Key Discussion Points and Insights

1. Stickers: Everywhere, for Everything (00:24–01:01)

• Stickers range from fun (unicorns, faces, price tags, even blueberry-scented ones!) to functional—including surgical adhesives.
• Quote: “There’s a million and one uses for them, from labeling groceries and decorating water bottles to wearable name tags or even patching up holes inside our bodies.” – Molly (00:31)

2. The Big Question: How Do Stickers Work? (02:52–04:35)

• Amira inspired the episode by asking: “How do stickers stick?”
• Stickers are named perfectly but the name doesn’t reveal their secret.

3. Up Close With Adhesives Using the "Zoomray" (04:35–07:41)

• Stickers stick because of special molecules called adhesives.
• Adhesives behave both like a liquid (able to flow into tiny surface bumps) and a solid (stay put once pressed in).
• Paper, up close, looks like a bumpy basket. Adhesive molecules fill these crevices when pressed.
• Quote: “Those aren’t ropes. Those are actually long molecules. Molecules are a group of atoms, which are the building blocks of everything.” – Molly (05:23)
• The importance of pressing the sticker: More pressure means more adhesive gets into the crevices, creating a better stick.
• Quote: “Pressing helps push those sticky molecules deeper into those nooks and crannies so they can really hold onto the surface.” – Molly (07:28)

4. Pressure-Sensitive Adhesives vs. Other Glues (11:55–12:37)

• Stickers are pressure sensitive adhesives: pressing activates their stickiness.
• Other glues (like white glue or hot glue) bond differently—by drying or cooling.
• Quote: “Stickers are what's known as pressure sensitive adhesives because you use pressure, like pressing them down, to make them adhere.” – Amira (12:00)

5. How Do Scratch-and-Sniff Stickers Work? (12:37–13:45)

• Special “smelly chemicals” are contained in tiny microcapsules in the sticker’s paper layer.
• Scratching breaks open these microcapsules, releasing the scent.
• Quote: “Those tiny little smell-filled bubbles are added to the paper used for the sticker. When you scratch that paper, you are actually breaking those tiny bubbles open. That lets the smell out.” – Amira (13:32)
• Fun side-discussion: If Amira could invent a scratch-and-sniff, it’d be baked goods!

6. Sticker Collections—The Fun Side (14:05–16:20)

• The Brains On! crew reveal their favorite and silliest sticker collections: “Creature creeper” stickers, price tag stickers, and more.
• Quote: “You need stickers with colors, with patterns, with monsters of varying sizes and abilities!” – Sandon (16:01)

7. Everyday “Hidden” Stickers and the Future of Stickers (18:28–20:44)

• Not all stickers are obvious: juice boxes are layers of material stuck together with adhesives (19:01).
• Professor Philip Messersmith highlights future innovations:
  • Fully recyclable adhesives to improve recycling (19:21)
  • Biodegradable and medical adhesives, such as patches to seal holes during surgery (19:41)
• Quote: “So imagine a patch, and then the surgeon just presses it onto the tissue, and it sticks to the tissue. So it's kind of like an internal bandage.” – Philip Messersmith (00:42, 20:14)

8. Stickers Summed Up & New Directions (22:10–22:31)

• Recap of how stickers stick: pressure, microscopic bonding, and staying power.
• Scientists are inventing materials to make stickers better for the environment and useful in medical care.

Notable Quotes & Memorable Moments

• [03:10] “I decorate any treasure boxes I have with stickers.” – Amira
• [04:49] “Zoomray, another great name, tells you what it does.” – Amira
• [07:41] “Wow. Now, it's just a very colorful flying goat sticker on a piece of paper. Who knew there was so much going on up close?” – Amira
• [09:43] “I would call our generation the coronial since we went through Corona 19 or whatever it was called.” – Amira
• [15:45] “I even have 1999. That one took forever to find. And guess how much it cost?” – Bob
• [17:02] “I was taking a spoon out of the dishwasher yesterday, and it nearly melted my fingerprints off, it was so hot.” – Sandon

Timestamps for Key Segments

• Intro and sticker uses: 00:24–01:01
• Meet Amira, the co-host: 02:44–03:54
• Zoomray microscopy lesson: 04:35–07:41
• Pressure and adhesives explained: 11:55–12:37, 22:10–22:19
• Scratch and sniff stickers: 12:37–13:45
• Sticker collections goofiness: 14:05–16:20
• Juice box and recycling adhesives: 19:01, 19:21–20:44
• Medical applications of stickers: 00:42, 19:41–20:44, 22:28
• Mystery sound segment: 08:16, 22:53–24:14

Fun Extras

• Mystery Sound: A fizzy, unidentifiable sound; revealed at 23:44 to be a homemade “volcano” (baking soda and vinegar) (23:44–24:12).
• Challenge to Listeners: Suggest a better name for “Gen Alpha” (current young generation) (09:22–09:49).
• Mailbag Q&As: Why do we use hot metal utensils? And, why isn’t “funner” a word? (16:41–17:46)

Takeaways

• Stickers are simple, fun, and found nearly everywhere, from art projects to price tags and even inside our bodies!
• The science behind their stickiness comes down to pressure-sensitive adhesives that fill in microscopic gaps.
• Innovations are pushing stickers forward to be more environmentally friendly and even medically helpful.
• The Brains On! crew keeps learning light and full of laughs—making even molecules and adhesives fun for kids and adults alike.

For more curious questions and sticky answers, tune in next episode!