Center of mass
You’ve probably seen plenty of smartphone holders or stands. You might use one to prop up a tablet to watch a movie, and maybe your parents have mounted one on the dashboard of their car to hold a phone being used for GPS navigation. But why buy one if you could build it yourself? In this project you’ll use the engineering design process to design, test and build your own smartphone stand.
Look around you. You’re probably surrounded by tons of everyday objects that don’t seem very “scientific.” Desks, chairs, lamps, doors, pencil holders, etcetera. Many of these objects, however, were probably designed by engineers who had to figure out solutions, such as: finding the best building materials; determining the weights the objects need to support; and devising efficient ways to manufacture them. If the engineers do their jobs well, you might never notice—but you certainly would if the chair you were sitting on fell apart or the lamp didn’t work!
Engineers design things using the engineering design process, which is different from the scientific method. The exact steps of this process may vary a bit depending on whom you ask, but they generally go something like this:
- Define the problem
- Do background research
- Specify requirements
- Brainstorm solutions
- Build a prototype
- Test the prototype
What does “iterate” mean? It means you might do some of the steps more than once! Things rarely work perfectly on the first try. You might think you have the perfect design for something, then test it and find out it doesn’t work at all—so it’s back to the drawing board! In this project you will get to try out the engineering design process and design your own cell phone stand.
- Smartphone or a “substitute” phone made from cardboard, coins and tape (see “Preparation”)
- Assorted office supplies and craft materials, such as cardboard, tape, rubber bands, paper clips, glue, etcetera (Because this is an engineering design project, there is no specific list of materials required for the activity. You can decide what materials you want to use.)
- Pencil and paper for sketching designs
- If you don’t have a phone available, you can make a substitute phone and design a holder for it. First, cut out a rectangular piece of corrugated cardboard about the same size as a smartphone. To make it heavier, tape a rectangular grid of coins to one side of the cardboard. It should now be about the same size and weight as a phone.
- Before you can start designing something you have to define exactly what problem you’re trying to solve. A problem might be, for example, “I need to be able to see a phone’s screen to use GPS while I'm driving” or “I want to be able to prop up a tablet to watch a movie without having to hold it.” The best solutions to these different problems probably won’t be the same. Figure out exactly what problem you’re trying to solve before you continue. In other words, why do you need a phone stand? How will you use it?
- Do some background research. If you have internet access, look around online at designs for different types of cell phone stands. Are there different kinds? How are they different? Do they all serve the same purpose?
- Specify the requirements for your phone stand. These will depend on how you plan to use the stand. For example, do you need it to work for phones of different sizes or just one phone? Do you want the angle of the phone to be adjustable? Do you need to make sure certain buttons or ports on the phone remain accessible? Do you need to be able to type or push buttons on the screen without knocking it over?
- Brainstorm some designs for your phone stand. Make sketches of them on paper and write down the materials you would need to build them. Try to come up with at least three different designs, and then think about how they would meet your requirements. Which one do you think will best meet the requirements?
- Build a prototype of your best design. You might need to start iterating at this point! For example, maybe the parts don’t all fit together like you thought they would. If you run into problems when building your prototype, it’s okay to modify the design or even switch to a completely different design if you realize it won't work as intended.
- Test your prototype! Try using it yourself or giving it to someone else to try out, and go through various real-world usage scenarios. For example, can you plug in the phone’s charging cable? If you push on the phone's screen, does it fall over? You could even try dropping it to see if it breaks. Does your prototype meet all of your requirements?
- If not, then it’s back to the drawing board—time to iterate and make changes to your design. Keep iterating until your phone stand meets all your requirements.
- Extra: Even if your stand meets all your initial requirements, you can still try to improve it. For example, can you make a stand with equivalent performance using fewer materials? In the real world this would save on manufacturing costs.
Observations and results
Did your phone stand work perfectly on the first try? You might have thought you had a perfect design on paper and then been surprised to find out it didn’t work as intended. Maybe there wasn’t enough friction between your stand and the table, so it slid around too easily. Maybe it was too narrow and fell over when you put the phone in or maybe the materials you used weren’t stiff enough and sagged under the phone’s weight. There are plenty of things that could have gone wrong—but that’s why you built a prototype and tested it first! That gave you a chance to make changes to your design to make sure it met all your requirements.
Engineers do the same thing—you wouldn’t want to design a product, start selling it and then find out it doesn’t work properly. Engineers almost always build and test prototypes before launching a final product. Now that you’re familiar with the engineering design process, what will you design next?
More to explore
The Engineering Design Process, from Science Buddies
Earthquake-Proof Engineering for Skyscrapers, from Scientific American
Paper Roller Coasters, from Scientific American
Science Activities for All Ages!, from Science Buddies