CHEMISTRY 2 min. of reading.

Creating fluorescent hydrogel spheres

Create your own fluorescent hydrogel spheres by hydrating them with a solution of water and fluorescein. Step by step.

Darío Otero
Darío Otero
October 10, 2023
Creating fluorescent hydrogel spheres

Today we’re going to learn how to make glowing water gel balls! We’ll explain all the steps to follow to do this simple activity correctly.

What You’ll Need

For this activity, you’ll need the following:

  1. Water gel balls. You only need a few because they’ll get much bigger when you add water.

Unsoaked water gel balls.

  1. Fluorescein. You only need a very small amount of this too.

Container with fluorescein inside.

  1. Water.
  2. A container where you’ll mix everything and soak the balls.

Let’s Get Started!

Making the Glowing Water

First, we need to make the water that will make the gel balls glow. This water will have water and fluorescein in it. How much fluorescein you use will change how bright your balls glow.

Water and fluorescein mixture.

It’s important to know that even a tiny bit of fluorescein can make the water very colorful, so don’t pour in a lot at once. Instead, dissolve it little by little.

Putting the Balls in the Water

Once your glowing water is ready, put the water gel balls into it in your container.

Remember that these balls grow a lot, so don’t put too many in the container, or they won’t all fit once they’re fully soaked!

After a few minutes, you’ll see the balls starting to grow as they soak up the water. After a few hours, they’ll reach their biggest size.

Making Them Glow with UV Light

Once the balls are full of the glowing water, you can shine ultraviolet (UV) light on them to see them glow! You can use a UV flashlight or try a simple trick at home.

For the homemade UV light, you’ll need your phone (or any flashlight), clear sticky tape, and a blue permanent marker. Stick a piece of tape over the flashlight part of your phone. Then, color over the tape with the blue permanent marker.

Repeat this a few times to get a stronger UV effect.

You can take a cool picture of your glowing balls by turning off the lights in the room and shining your phone’s light on them. Easy and awesome, right?

Photograph shining ultraviolet light on the glowing water gel balls.