Fingerprint sensor has gradually become an integral part of our smartphones. Today, a fingerprint studded smartphone is available for as low as Rs. 5,999 ($90 US), which is quite remarkable, since a year ago the same feature was exclusively reserved for flagships.
Recently (in the month of march to be precise) Qualcomm refreshed its line of mobile chipsets with Snapdragon 820 SoC in the lead. It grabbed headlines not only for performance benchmarks, but also for a new fingerprint sensor technology, which they termed as Ultrasonic Fingerprint Sensor. The Chinese company LeEco became the first firm to embrace this new technology with their new smartphone or as the company likes to call it “superphone” Le Max Pro and then in Le Max 2. Let’s get into the details to find out how this works and what advantages it have over existing optical or capacitive fingerprint scanners.
What is ultrasonic fingerprint scanner?
This new Sense ID developed by Qualcomm uses sonic technology to register finger grooves. It employs acoustic ultrasonic sound to map users fingerprint in any state. It is fastest and most secure fingerprint sensor currently available in the market. Unlike existing optical and capacitive fingerprint sensor which depends on 2D mapping, Ultrasonic fingerprint sensor register minute details in 3D and are thus very hard to fool.
How does Ultrasonic Fingerprint Sensor Work?
An ultrasonic fingerprint sensor consists of a sonic sound transmitter and a receiver. The sensor transmits a high-frequency sonic sound each time a finger comes in contact with the sensor. The emitted sound waves penetrate through epidermis layer (outermost layer of the skin which generally carries sweat, food oil and grease) and reflects off from the dermis layer (under top layer of skin) back to the receiver. In this process, it registers a unique print which also includes ridges and sweat pores. Sonic waves are capable of scanning through all most all plastics, sapphire crystal, and metal.
So what does that mean for Aam Aadmi (common man)?
- It means that scans by Ultrasonic fingerprint sensor won’t get affected by wet hands, food grease, oil or dirt.
- It also means that it becomes almost impossible to by-pass fingerprint authentication, and users can better safegaurd their privacy and security.
What are the other types of Fingerprint Sensors we currently have?
Prior to the arrival of ultrasonic fingerprint sensor, we have seen two sorts of scanner: Optical Scanners and Capacitive Scanners. Optical Scanners are the most basic ones. As the name implies, they employ image capturing technique (basically a photograph) and use algorithms to understand unique patterns such as ridges on the finger by examining dark and light sections of the image. These optical Sensors are equipped with arrays of diodes and LEDs lights. Optical Scanners are generally used in office attendance biometric systems, hospitals, Aadhar card registration, etc. The biggest drawback with optical fingerprint sensors is that they are easy to fool. They can’t be used to secure sensitive details.
Also read: Do We Really Need 6GB RAM In A Smartphone
Today, almost every smartphone – from iPhones’ to Galaxy phones’ to affordable Chinese phones – all uses capacitive fingerprint scanners. These are the most common type of fingerprint sensors today. These sensors rely on small capacitor circuits to store electrical charge when a finger touches the conductive plates. This charge stored is somewhat different for each individual due to finger ridges.
Capacitive sensors in smartphones will soon be replaced by Ultrasonic ones, which are faster, more accurate and more secure.