The ability to identify yourself by simply touching a sensor has been a sought-after feature for years. Nowadays, fingerprint scanners are present throughout our daily lives, a common feature of our smartphones, computers and other devices.
In this article, we’ll take you on a journey to learn about the evolution of the fingerprint reader. You’ll learn about the most popular forms, and more.
The first fingerprint scanners in phones
The first phone with a fingerprint scanner to hit the market was the Pantech Gi100, released in the first half of 2004. The fingerprint scanner was mounted in the middle of the D-pad and was the main topic of discussion. for an otherwise unspectacular device.
In the years to come, companies like Toshiba and HTC added fingerprint scanners to their phones. It was a step forward in the widespread use of fingerprint scanners on phones.
Fingerprint scanners on modern smartphones
In the mid-2010s, fingerprint scanners on smartphones really took off. Technology has become a common feature for flagship smartphones. Apple’s first phone with this technology was the iPhone 5s, and Samsung’s was the Galaxy Note4.
In the second half of the decade, fingerprint scanners were on the flagship devices of new releases from all major smartphone makers.
There is nothing really special about the fingerprint scanner today. The new standard that has gained momentum is the in-display fingerprint reader. The first phone to feature this technology was the Vivo X20 Plus UD, released in 2018.
Now, most of the major original equipment manufacturers (OEMs) of smartphones, such as Samsung, OnePlus, and ASUS, are installing fingerprint scanners built into their phones.
The technology behind modern fingerprint scanners
In 2021, three of the main types of fingerprint scanners in use are: optical, capacitive and ultrasonic. Each method uses completely different branches of science to achieve the same result.
1. Optical fingerprint readers
Optical fingerprint scanners use light to create an optical image of the fingerprint. This is then stored in the device memory. When the device detects that there is a fingerprint on the scan area, it compares it to the saved image.
Inside the optical fingerprint reader, there is a three-sided prism. The finger is placed on one of its faces. A light source shines through one of the adjacent faces. The light bounces and comes out the other side, hitting a light sensor. It works much like a digital camera.
Although this method is easy to understand, it is not really space efficient. While this technology can be used in larger machines, it’s not the best for smartphones. A big downside to optical fingerprint scanners is that they can be tricked into placing a photo of a fingerprint on the sensor. Hackers can bypass your fingerprint reader in a number of ways, and this is one of them.
2. Capacitive fingerprint scanners
Capacitive fingerprint scanners are common in the smartphone world and do not require light to operate. The technology used by capacitive fingerprint scanners is similar to that used in touch screens.
The science behind capacitive fingerprint scanners is a little harder to explain, but it can make sense with a rough oversimplification. The scanning area uses a capacitor array circuit (roughly speaking, it is an area that detects changes in electrical charge).
When you place your finger over the scan area, the ridges of your fingerprint (the protruding parts) come into contact with the die. When the edges come into contact with the scanner, they change the electrical charge in that area.
The only areas affected are specifically those where the ridges touch the network. Valleys (the areas of your fingerprint between ridges) do not come into contact with the network. This allows the matrix to identify the structure of the fingerprint. Thanks to this, the technology can produce an image of the fingerprint.
One of the advantages of this type of fingerprint scanner is that the images cannot be used to deceive them, as is the case with optical fingerprint scanners.
3. Ultrasonic fingerprint scanners
Ultrasonic fingerprint scanners are a bit easier to explain. When your finger is placed over the scanner area, a very high-pitched noise is emitted. When the sound waves bounce back to the sensor, the latter then performs its measurement.
Sound waves hitting ridges return to the sensor before sound waves hitting valleys. The sensor analyzes which waves come back first and builds a fingerprint profile map based on that.
Fingerprint scanners have come a long way
Every technology we take for granted today has a long history stretching back decades. Fingerprint scanners are no different. The technology we use to unlock our phones has gone through over 100 years of development before we even unlocked its very first phone.
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