What You'll Get
Choose Between Two Options
- $9 for one tempered-glass screen protector for an iPhone 5, 5c, or 5s ($29.99 value)
- $43 for screen repair for an iPhone 4 or 4s ($79.99 value)
Touchscreens: Power at Your Fingertips
To learn what’s behind the face your smartphone shows to the world, read on.
Most electronic touchscreens—such as the kind on your smartphone, perhaps—rely on electricity. Not just the obvious electricity provided by their power supply, but your electricity, as in the tiny amount that runs through your body or the large amount that runs through your body if you’re a Frankenstein. Capacitive touchscreens are set up to detect any change in the electromagnetic field they produce, such as that created by a bare fingertip. Beneath the glass screen, a network of electrodes stands ready to relay information about the location of the touch to the device’s microcontrollers and translate it into a command.
Another Path: Resistance
There is another, slightly older form of touchscreen technology, which requires the hand to apply not electricity but pressure. This type is known as a resistive screen and is frequently still found at checkout counters and on PDAs. Beneath its surface are two layers of conductive material. Pressure forces the two layers to connect, completing a circuit; different points on the screen will produce a current with different voltage, which allows the system to pinpoint the precise location of the touch. Although these screens are lower-resolution and can’t respond to multiple simultaneous touches, they do have one advantage over capacitive screens: they’ll work even if you’re wearing gloves or oven mitts.
- There are plenty of other, less common ways to create a touchscreen. Some devices send ultrasonic waves continually across the screen, which are interrupted upon contact; others, including Microsoft’s Surface tabletop screen, sense changes not in pressure or electric charge but in light.
- Capacitive screens have also been developed that can register how hard you’re pressing. When you press down harder on anything you’ll notice your fingertip spread out to contact more of the surface. Newer screens take advantage of this fact and track whether you’re contacting an increasing number of capacitors.
The Fine Print
Promotional value expires 90 days after purchase. Amount paid never expires. Limit 1 per person. Limit 1 per visit. Valid only for option purchased. Not valid with other offers or promotions. All goods or services must be used by the same person. Must use promotional value in 1 visit. May be repurchased every 30 days. Merchant is solely responsible to purchasers for the care and quality of the advertised goods and services.