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What is an ultrasonic fingerprint sensor?

If you’re weighing up easier ways to unlock your phone, you might be wondering what an ultrasonic fingerprint scanner is. In this article, all is revealed.

When you’re setting up your phone, you’ll often get the choice of entering a PIN or pattern, using facial recognition, or scanning your fingerprint in order to unlock it and get inside securely. However, did you know that there are different types of fingerprint sensors?

A capacitive fingerprint scanner works by registering how the ridges on your finger alter the charge in capacitors when pressed against them, creating a map of your fingerprints in this way. An optical fingerprint scanner, by contrast, shines a light onto your fingerprint in order to detect its shape by the light and dark areas that it scans. Additionally there’s one more type of scanner, and that’s the one addressed by this article.

How does an ultrasonic fingerprint scanner work?

Ultrasonic fingerprint scanners work by transmitting an ultrasonic pulse of inaudible sound waves against your finger when it’s pressed against the scanner, and this information is bounced back to a receiver. This way, it can map out the ridges on your finger for an accurate three-dimensional rendering. This type of technology can be hidden underneath a display (unlike a capacitive sensor), and is doesn’t need to light up when in use (like an optical scanner).

What are the benefits of an ultrasonic fingerprint scanner?

One major benefit is that you can still use an ultrasonic fingerprint scanner even if your fingertip is wet or oily at the time, due to that three-dimensional scanning. So if you’ve been caught in the rain or are just back from exercising, you should still be able to unlock your phone as usual.

What’s more they’re probably also the most accurate of the three methods listed here (though still not foolproof), so your phone is less likely to be opened by someone who is not you.

What are the disadvantages of an ultrasonic fingerprint scanner?

One disadvantage is that the technology isn’t that widespread yet across the price range; they’re mainly concentrated among premium Samsung handsets, such as the Galaxy S22 Ultra, and so this elevated cost is the major thing that counts against them.

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