What properties does a phone case need to protect your phone from scratches and the glass from breaking? To better understand it, let's do a simple science experiment together:
Springy ball vs. fragile Christmas ornament - which will break, which will bounce and why?
Take a bouncy ball and let it fall to the ground from a fixed height on a hard floor. It will not break but it will bounce. The ball doesn't break because it is very elastic. And the higher it bounces, the more elastic it is! The technical term for this is a high elastic limit. If you took a Christmas ornament made of glass for the dropping experiment it would most likely break. That is because it has a very low elastic limit and the mechanical load it experiences when hitting the ground is more than can be elastically absorbed by the material.
Your phone also has an elastic limit. If it is exceeded, the phone can scratch or the glass might break. And because we don't want that, we put a phone case on our phone. The aim of the phone case is to capture the mechanical energy without damaging the phone case itself. That is why we need a very elastic material.
What happens when your phone experiences more fall energy than it can take
However, you don’t want your phone to bounce away, so you need some dampening as well. A bag of sand for example is dampening. If you let it fall on the floor, all the mechanical energy is absorbed – so no bouncing. But a sand bag around your phone isn’t very practical. This means we are looking for a material that can do both: Be elastic enough so it doesn't break and dampening enough so it doesn't bounce.
Polycarbonate and silicone have a very high elastic limit with good dampenig properties, thus are two good choices in the fossil world. A fossil material that stays in the environment forever is however not a sustainable choice in our opinion. So we set out to find an earth-friendly alternative, which was not easy at all. Long story short, we found an all-natural solution!
Our Material - based on a Biopolymer and all-natural ingredients has everything it takes to protect your phone
We incorporated just the right amount of dampening and elasticity into our biopolymer material. From a material stand point the thicker the phone case, the better. Since a centimeter-wide block around your phone isn’t usable, we optimized it to get a thin case. The magic lies in the all-natural ingredients, their size, the distribution and even the form of the sprinkles. As a result the case does not break under normal use because of the high elastic limit of the optimized biopolymer and it absorbs shocks due to its inner structure. We made it to match your lifestyle with good scratch protection and drop protection by our unique design.
Now you can stop getting your head around the physics. We already did this for you! Get yourself a kepu case :)