Almost all smartphones nowadays have Android Fingerprint Sensors, the high-end smartphones that is. However, while we love to swipe our fingers to unlock our phones, some users, owners of these high-end devices, only need to touch the fingerprint sensor, usually at the back of the phone, to unlock it. Ever wondered how the fingerprint scanners on android are able to perfectly distinguish between your middle finger and the index finger? 
There are a few aspects to how the fingerprint scanner works in Android and we will tackle three main types of fingerprint sensors and how they work to secure your phone.
Types of Android Fingerprint Sensors
Optical Fingerprint Sensors
Optical scanners and sensors are among the oldest fingerprint sensors and they work using light. They are in very few phones and have been mostly phased out by better scanners. Basically, the sensor takes a picture of the fingerprint and compares it with what it had on record. If it finds a match, it unlocks and vice versa.
Read Also: How to Run Multiple WhatsApp Accounts on a single Android phone.
Capacitive Fingerprint Sensors
This type of fingerprint sensor works in the same way as a capacitive touch screen and is the most common by today’s standards. When you place your finger on the fingerprint sensor, it sends an electric charge into the system where the phone compares the pattern of the fingerprint to what has been recorded in the phone’s setup.
Ultrasonic Fingerprint Sensors
These ones are the future and are on very few phones. They work in the same way proximity sensors work. When you place your finger on the sensor, a sound is sent to hit against it by fine sensors. When it comes back, the phone has other sensors that will record it and analyze the pattern of your fingerprint. It will then match it with the fingerprint on record to unlock it.
While these processes seem long, they are undertaken in microseconds such that you do not notice the lag between the time you touch the phone and the time it unlocks especially when you are using the latest smartphones. Thanks to advancements in technology, the price of phones with fingerprint sensors keeps going down to enable everyone to have a secure phone.
