One of the world’s many problems is that there’s not purified water everywhere. In many places all around the world, people have difficultly getting drinkable water. Luckily, there’s a solution to that: LifeStraw.
LifeStraw is a straw-like water purifier. LifeStraw is made of a durable plastic so it won’t break easily. It has a filtering technique where there are tiny holes (0.2 microns across) in the filter so as you drink, the filter stops all the bacteria and dirt from entering. Thus, clean water for you to drink. You can clean it by blowing into the straw. By blowing into the straw, you get rid of everything that was in it. LifeStraw to purify about 1,000 liters (264 gallons) before it needs to be replaced. It also has a string so you can wear it around your neck.
https://science.howstuffworks.com/environmental/green-tech/remediation/lifestraw1.htm
https://www.youtube.com/watch?v=i82YD7uvi2s
LifeStraw uses no batteries and no chemicals. LifeStraw has a little bit of charcoal at the tip of the straw so that when you drink the purified water it will have a neutral taste. It relates to engineering because it by engineers trying to help other people. Engineers had to test multiple prototypes get this right and make a difference in people’s lives.