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Why a sausage can do what your gloves cannot - Charles Wallace and Sajan Saini

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In 2010, South Korea experienced a particularly cold winter. People couldn’t activate their smartphones while wearing gloves, so they began wielding snack sausages— causing one company to see a 40% rise in sausage sales. So, what could sausages do that gloves couldn’t? In other words, how do touchscreens actually work? Charles Wallace and Sajan Saini dig into the science of touchscreens.

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TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Sajan Saini , Charles Wallace
  • Director Luis Torres, Mr. Flama
  • Narrator Addison Anderson
  • Storyboard Artist Luis Torres, Mr. Flama
  • Animator Luis Torres, Mr. Flama
  • Art Director Luis Torres, Mr. Flama
  • Sound Designer Jan Willem De With
  • Director of Production Gerta Xhelo
  • Producer Anna Bechtol
  • Associate Producer Abdallah Ewis
  • Editorial Producer Alex Rosenthal, Cella Wright
  • See more creators
Additional Resources for you to Explore
History of Touchscreens

Wanting to know more about this history and evolution of touchscreens? Head over to this Ars Technica review or this WNYC radio article. You might also be interested in learning more about present day touchscreens and how they've transformed our world. Learn more about the future of touchscreens, finger free-phones and full-body gesturing. If you're craving a more technical overview of the history of the 13 different touchscreen technologies, this is a good place to start.

Capacitive Technology, and its Chemistry

Fascinated by projected capacitive technology? Check out the following resources.

Here is a great summary of the basics by Texas Instruments. Projected-capacitive touch has grown quickly. This article examines all aspects of projected-capacitive touch technology, delving into sensor, controller, and module details. If you want to find out more about the different kinds of touch screens and how they are used, you’ll want to head over here. You’ll dig into the difference between projected capacitive versus capacitive tech. 

Learn about the complex of materials that need to be assembled to create these interactive screen in this technology brief by 3M and the chemistry of materials in this article by the American Chemical Society. 
Looking to get technical? Check out this technical brief by 3M on project capacitive technology. And if you’re looking for a challenge, head over to this theory article or this article that explore four categories of touchscreen technology. 

How Touchscreens Work and Don’t Work

Read up on how water confuses your touchscreen here. Dig deeper by exploring water, conductivity and free ions. Capacitive technology works because of the amount of water in our bodies. Learn more about that here. Wondering how and why a banana can swipe your touchscreen? Read about it here. And if you want to figure out the conductivity of different types of materials, check out this article in Sciencing.

The Building Block: Capacitors

If you curious about capacitors, how they work and their history, start with this article over at How Stuff Works. You might also want to read here for more in-depth explanations and applications of capacitors. Finally, this article in Electronics Hub gives a (highly technical) introduction to the different types of touch sensors: Working, Resistive, and Capacitive.

What’s Next: Gestural Interactions and Haptic Displays

Finally, take a look at this forward-looking MIT Technology Review piece on where this technology may be headed, next. One of the transformative next-generation technologies includes haptics, is ability transmit and understand information through the sense of touch. Dig deeper into haptic display screens here








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About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Sajan Saini , Charles Wallace
  • Director Luis Torres, Mr. Flama
  • Narrator Addison Anderson
  • Storyboard Artist Luis Torres, Mr. Flama
  • Animator Luis Torres, Mr. Flama
  • Art Director Luis Torres, Mr. Flama
  • Sound Designer Jan Willem De With
  • Director of Production Gerta Xhelo
  • Producer Anna Bechtol
  • Associate Producer Abdallah Ewis
  • Editorial Producer Alex Rosenthal, Cella Wright
  • See more creators