Boundary seals that help keep a certain environment sealed in while keeping the world out are everywhere.
If you look around your home, you may be surprised to see there are seals surrounding every door — and not just at the bottom. Your oven, microwave, and of course refrigerator door all have seals around them.
All these seals are different, yet they perform the same function. Your microwave is especially interesting, as its primary purpose is to keep microwaves from escaping the chamber that’s cooking your food. Your refrigerator seal has a magnet built into it, which keeps the door sealed shut.
Boundary seals are also found in many cell phones and electronic devices, keeping them water-resistant or water-proof (depending on the manufacturer). And in the industrial world, we have seals to create explosion-proof boxes in hazardous environments. The simple O-ring is found at the end of every cylinder cap to keep fluids in and the environment out.
We