You might remember over the summer we took part in a couple of brilliant engineering challenges with The Holiday Makers.
The Holiday Makers is an absolutely fantastic series of fun and free engineering inspired activities for parents to do with their children. We have found it to be a great source of ideas and inspiration, with something to appeal to everyone.
The Holiday Makers is part of a government initiative called the Year of Engineering which aims to shake-up people’s ideas about engineering and inspire future generations of innovators, inventors and problem solvers.
Did you know that there’s a huge shortage of young people attracted to engineering jobs and a lack of diversity in the engineering profession? So this initiative is very much needed.
Easy Slime Recipe for Halloween
The Holiday Makers challenged us to make some Halloween Slime. There are lots of different recipes on the internet for slime, but this is the one that has worked the best for us.
What you need to make no borax slime
¾ cup of PVA glue
¼ cup of water
1 teaspoon bicarbonate of soda
1 tablespoon saline solution
Glitter and other decorations – optional
All you need to do is mix the ingredients together, adding the saline last. The mixture will start to stick together as soon as you stir in the saline solution ( slime activator ). It’s great fun to watch and do!
Can you mix slime colours to make a new colour? Our yellow and blue slime made green slime!
How far can you stretch the slime?
Can you find the perfect slime recipe by changing the amount of glue, water and baking soda?
Work as a team to make a slime sheet!
The engineering of slime
Slime is called a non-Newtonian fluid because their viscosity changes with changes in pressure or temperature. Another very simple non -Newtonian fluid can be made using just cornflour and water. This sticks together to form a solid when pressure is applied ( you squeeze it in your hands ) and flows when pressure is released.
Glue flows because the polymer chains slide over each other easily. The saline solution reacts with baking soda to form borate which forms bonds between the polymer chains of the glue. This is called cross linking and is what makes the slime mixture stick together.
Materials engineers design and make new materials every day. You can watch an interview with a materials engineer and discover the engineering behind biodegradable glitter on the Year of Engineering YouTube channel.
Post in collaboration with The Holiday Makers