Aug 23 AT 11:28 AM Brooks Barnard 26 Comments

What you need to know about phone cases and drop protection [WARNING: Science content]

smartphone case feature

There are a lot of different case options out there: thick ones, thin ones, squishy ones, hard ones, colorful ones and clear ones. Nick Sarafolean just wrote a great piece on how you can use a case with your phone to make it more unique. But cases can do even more. A lot of us use cases for protection, and there are many of us out there that have a tendency to drop our phones sometimes. That can get expensive.

Hopefully people have figured out by now that these smartphones we carry around with us everywhere are worth more than the $200 price tag advertised by your carrier. Even the free on-contract phones are fairly expensive at full retail. High-end smartphones can cost $700 or more, and if you’re not doing something to protect them or paying for insurance, one drop can cost you a pretty penny. Either that or you deal with using a broken phone, if you’re the kind of person that can handle it. That’s where cases come in. Cases are an obvious solution to protect our phones. But why? And what should you consider when buying a case?

How do we minimize impact?

Your smartphone is a fairly rigid piece of a equipment, and it has a relatively brittle display. What I mean by rigid is that there isn’t much on a standard phone that can absorb energy in an impact, so rather than absorbing a shock and limiting the impact to a region, the energy from an impact will be transferred through the entire device. And what I mean by brittle is that the glass on your display isn’t able to bend very far without fracturing. Most of the glass used in smartphones these days is much tougher than a standard glass, meaning it can absorb more energy than a window or a drinking glass, but it’s still more brittle than the plastic on the back of your device. So how do we combat this? With science, that’s what.

helmet impact energy-horzLet’s take a simple bicycle helmet for example. Helmets are there to protect your precious brain in the case that something ridiculous happens while riding your bike. It’s made of many pieces to create this protection, but the most important thing it does is slow down the impact. In a simple graph provided by a Bicycle Helmet Saftey Institute, we can see the difference in impact energy between a head with a helmet and without. As you can see, the impact energy curve with the helmet is extended over a longer period of time and the peak is greatly reduced. This is done through the soft foam on the helmet squishing and the harder foam crushing, thus transferring less impact energy to your brain. That impact energy spike is the dangerous part. If you can mitigate that spike it saves lives. It’s been proven. It’s science.

How does this apply to cases?

Your smartphone is less important than your brain, but we can apply the same principles to protecting your smartphone. When selecting a case, choose one that’s made from a material that isn’t rigid or hard, but is more flexible or squishy. Pick a case that can absorb energy. Some of the common energy absorbent case materials are silicone and thermoplastic polyurethane, also known as TPU. This is what makes the popular OtterBox brand so successful and has given them such a good name. Their cases are typically made of silicone (at least one of the layers) and, depending on the series, can be very thick as well making them very efficient at absorbing energy. I don’t care for their bulkiness, but from what I hear they do a dang good job protecting mobile devices.

There are case options beyond OtterBox. This isn’t intended to be a post promoting OtterBox cases. This is a post promoting the use of a relatively soft case over a hard case if you’re hoping to protect your phone from a drop. I want to help you save money. A hard, rigid case will not absorb impact energy unless it breaks in the fall – which I’ve seen happen – but you shouldn’t count on that. What will most likely happen is the energy will be passed directly through the case to the phone without a decrease in intensity. Additionally, I’m not promising that a soft case will always protect your device in the case of a drop. Helmets aren’t 100 percent effective, but wearing one is significantly safer than not.

So what’s the bottom line?

If you’re looking for a case to protect your phone in a drop, add the terms “silicone” or “TPU” to your search. You may limit the cuteness or the coolness of your options, but you will in increasing the effectiveness of your protection. There may be other case materials I haven’t mentioned that are effective at absorbing impact energy. If I’ve left something out, let us know in the comments below. Fill in the community about your favorite cases, and why they’re your favorite. Tell us about the incredible drop your phone survived because you were using a case made to absorb energy. Or tell us horror story about a hard case or not using a case. Let’s all work together to help each other have great smartphone experiences. And also, please wear a helmet when riding your bike.

Brooks is an engineer living in the Bay Area recently dislocated from the Great Northwest. He's an Android enthusiast who decided to start doing something (productive?) with his countless hours surfing the interwebz and addictive ROM flashing and began writing. He has a hot wife, is a father of two, an avid F1 fan, and enjoys watching sports when he can. His current devices include the Nexus 5 and 7 (2103) both running stock roms rooted and modded with Xposed Framework (but this is subject to change). You can follow Brooks on Twitter @Brooks_Barnard.

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