Aug 23 AT 11:28 AM Brooks Barnard 30 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 Android modding and theming. He has a hot wife, is a father of three, an avid F1 fan, and enjoys watching sports when he can. His current devices include the Nexus 6 and 7 (2103) both running stock roms and may or may not be rooted. You can follow Brooks on Twitter @Brooks_Barnard.

    Most Tweeted This Week

  • BlazeHN

    I use a Note 3, a huge phone, so putting a thick Otterbox or similar on it would be overkill for my pants pocket and for my hand. So I choosed this one to at least give some scratch protection:

    When I placed the order was the slimmest posible case, I have drop my phone with this case often, sometimes even big drops and it was just fine until some days ago when some uncle was using it as flashlight and drop it on the ground from hand distance, result: screen cracked (-_-) touch still fine, just the glass broke but people charges me the whole screen module to repair it since they dont like to chance only the glass (too risky they says)… sighs… anyways even then I dont feel like buying a huge case because that would be too much bulk… or maybe not?

    • Cals

      People told me that about my s3….”impossible to repair the glass because it’s fused”. One hair dryer and a 5 dollar replacement screen from Amazon later I fixed it myself anyway. I’m the clumsiest person alive but it was still very easy – you just have to be very patient.

      • Cals

        Btw if you do repair it yourself the only “risk” is breaking the digitizer. (Which is what they want you to pay to replace anyway) so basically there is no risk

  • 573W1E

    Are those cases pictured the Cruzerlite Android circuit ones? Picked one up for my G3 a week or so ago for about £10 and it’s the best case I’ve ever bought. Compliments the G3′s design so well.

  • Brooks Barnard

    No, the cases are some generic 8-pack of TPU cases that my wife bought off of Amazon. But I do really like Cruzerlite TPU cases. They’re a great way to protect your phone and show off some Android Andy.

  • SGB101

    Your bike helmets data doesn’t take into account the higher number of brocken necks due to extra weight, or the greater chance of risks do to the feeling of being ‘protected’.

    Most pro helmet campaigners all refer to one or two flawed research papers, ignoring the larger amount of data that outlines the risk of helmets.

    • namesib

      lol idiot

      • SGB101

        I agree

    • Nigel

      You are correct.

      Helmet opinions are either well informed and anti-helmet, or poorly informed and pro-helmet.
      At low speeds the human will survive as after all we evolved capable of landing at human speeds.
      At high speeds the helmet adds itself as the cause of the problem transmitting force from the front of the skull which is strongest to the rear, it causes more rotations which cause more internal brain damage and neck injuries.

      I see lots of people with no knowledge whatsoever.

      They also probably believe in a god, and tooth fairies too. Oh and don’t turn that light off at bedtime or the thing in the closet will GET YOU!

      • Brooks Barnard

        Are we confusing impact force with the helmet creating a larger moment (and I’m not talking about a *moment* in regards to time) or maybe torque on the neck? Because I get that side of the argument. But it doesn’t make sense that a helmet could create a larger peak impact force on the head. Or am I missing something significant?

        So, if I get what you’re saying correctly, you think helmets are designed poorly. I think you’d probably be a proponent of them if they were lighter and thinner but could still absorb energy, correct?

    • Brooks Barnard

      Well, since writing this post I have now learned some arguments for not using a helmet, however your phone does not have a spine, so the general principles within this post are still correct. A softer case will absorb energy and thus transfer less energy to the rest of the phone.

    • John Patrick

      Congratulations, that is the absolute stupidest thing I’ve seen posted here. Ever.

  • John Patrick

    On past phones I became a fan of TPU cases – relatively thin and provides a good grip in the hand. This is a pretty good solution for preventing drops and protecting the phone in up to a three foot drop into a flat surface. Especially if the case has a lip deeper that the phone thickness. For over a year now my new favorite for my Galaxy S 4 is a Slim-fit case mode of matte poly-carbonate.
    It’s thinner and harder so it doesn’t get hung up and sometimes pull the whole pocket out with the phone and simply snaps on or off the phone. I’ve dropped my phone three or 4 times since using since using the case. Max drop height was pocket to ground while standing onto pavement. No damage to case or phone. I was lucky. But as the saying goes – Luck is where preparation and opportunity meet, in my case preparation is having a case in the phone.

  • Markus

    I use an Evercase tpu and have done so for past two phones cheap on Amazon thin and had a kickstand. Cost like $8.00.

  • Keith Tomlinson

    I have been using this case for a couple months. It’s absolutely the best case I have ever owned, I have had a lot of cases over the years. My Wife works in the mobile retail industry and gets cases and other accessories before they are released to the market, this was a freebie for me. But I’d pay whatever for it. I’m a technician for a large telecommunications company and I work outside 80% of the time and have dropped my S5 more times than I can remember, still looks and works like new.

  • p51d007

    I don’t “carry” my phone in my hand 24/7, like I see a ton of people do these days. I keep it in a faux leather belt clip. Have for the past 5 years. I use the cheapest plastic case for the back of the phone, to protect the back from scratches, and to put the camera lens just a little off the table so it won’t get nicked or scratched. I don’t know how people are so clumsy with their phones, but, considering the price, why they have to have them in their hands 24/7 just amazes me.

  • misterdestructo

    I use a clear Tech21 Impactology case for my HTC One m8, it has a special shock absorbent lining that has proven effective, at least for minor drops. Unfortunately I could only find the case on the company’s website and had to pay $15 in shipping from England. Otherwise it’s perfect, I love the look of it, it helps with the slippery issue some have mentioned with the m8 and I actually like the volume controls of the case better.

  • SGB101

    the m8 is the first phone ive put a case on ever, which is a bit ironic as im using the case as i like the look of the phone so much. it just makes no rational sense to hide it.

    im using the one that came with it, i did get a dot case, but i didnt like it, used it for 10 mins and put it in a draw.

    also im using a screen protector on it. the first time since the G1, it is a tempered glass one, a friend recommended it, and its really good link

  • aranea

    Why warning about “Science content”? Is it dangerous to read or NSFW because it’ll get your brain working and make you look like a nerd? Depending on knowledge should be the standard not the exception!

    • Brooks Barnard

      Maybe add thing science warning was a bit silly, but I used it in hopes to invite those who are interested in more than just a general discussion on phone cases. In general, a blog post on cases sounds horribly boring, but I thought people might enjoy learning about and discussing impact force and how to minimize it.

      I think people enjoy the science behind things in doses. Am I right?

      Also, if you think the [WARNING: Science content] tag is silly, what other ideas do you have to let you know this is more than an opinion or news post? What would be inviting to you to let you know this post has some science or engineering discussion in it?

      • aranea

        How does [This post is powered by Science. ENJOY!] sound like?

        • Brooks Barnard

          It’s a little long, but I like the sound of it ;-)

          • aranea

            Then only [Powered by Science!]

  • ujosmadre

    i have sony xperia t and i have hard case, so he is well protected

  • HeyUOvahThere

    Go Ballistic!!!

  • MeHere

    I have an OtterBox Commuter Series Case for my HTC One Mini and I really like it! It has two layers, a silicone inner layer and a polycarbonate outer layer. It also comes with a screen protector but I don’t use it. I got it when I got my phone last October and haven’t had any problems with it. I’ve dropped it a few times plus I have a cat that loves to knock things off my computer desk etc.
    I had another HTC phone before this one and also had an OtterBox case for it. Yeah, they might be more expensive than other cases but I don’t think I would buy another brand.

  • Emily

    I’m using a thin, clear TPU case for my iPhone 6+. It’s a big phone, so I want a thin case. Sounds like I did ok in getting a TPU case. One of the great things about this case – it came with a free screen protector in the package.

    And it didn’t cost a lot, clear TPU case & screen protector for just $9.99.

    I’ve only had it a couple of weeks, but all is good so far.

  • Amanda
  • Amanda
  • Noah Smith

    Just the explainer I was looking for. Thanks!