Samsung Galaxy S9 Fingerprint Reader

As early as 2012, hardly any major smartphone manufacturer had a phone with a fingerprint scanner, save for the Motorola Atrix. The fingerprint scanner was a great addition to the smartphone arsenal since it provided another layer of security save for the classic PIN/password/pattern ones that we were used to.

Motorola Atrix (top)
Samsung Galaxy S5 (bottom)

Fingerprint scanner technology, like any other technology started rough. We started off with scanners that required you to slide your fingers across the scanner. This was true with the Motorola Atrix and the Samsung Galaxy S5.

Capacitive fingerprint scanners started getting popular thanks to the iPhone 5S (Apple and their brilliant marketing team call it TouchID) and Apple improved its speed greatly with subsequent release until they were axed from the iPhone in 2017 with the release of the iPhone X.

Here is the thing: There was nothing wrong about the capacitive fingerprint scanner. It worked really well and in flagship smartphones, it was almost instantaneous. We even started seeing capacitive fingerprint scanners appear in budget phones, which was a win for everyone.

FaceID hardware on the iPhone X

Something changed in 2017. The iPhone X was released and it dropped TouchID in favour of face tracking technology which they call FaceID. Suddenly, the excellent capacitive fingerprint scanner that we had on iPhones was no more and about to be phased out. The FaceID system on the iPhone X was a good substitute to TouchID but it was slower than it at first and it is yet to catch up on speed.

On the Android side, companies tried with iris scanning technology and failed. Some like Oppo and Huawei tried with face tracking tech like the iPhone X and it felt like beta tests.

The rise of the under-the-display fingerprint tech

Huawei Mate 20 Pro optical fingerprint scanner (top)
Samsung Galaxy S10 ultrasonic fingerprint scanner (bottom)

Flagship Android phones started to drop the capacitive fingerprint scanners officially in 2018. We saw the rise of two in-display fingerprint scanners: optical and ultrasonic. We saw the optical fingerprint scanners with the likes of the Huawei Mate 20 Pro and the OnePlus 6T and we still see it with the P30 and the P30 Pro.

They work in rather different ways. Optical fingerprint scanners illuminate your finger using an LED light where a sensor at the back detects and creates the fingerprint image when you set it up. When you tap on it, it lights up to scan the registered fingerprint, validates it and logs you in.

The ultrasonic fingerprint scanner works in a slightly different way. It uses ultrasonic sound waves (typically 200khz) to create a three dimensional image of your fingerprint. These soundwaves bounce off your finger and onto the phone allowing the tech to see the ridges and valleys of your print.

These technologies are pretty cool compared to the classic capacitive fingerprint scanner since they reside under the display thereby saving space. However, they have a fatal flaw where currently they are way way slower than capacitive scanners.

I have used both technologies on the Huawei Mate 20 which has the optical scanner and the Samsung Galaxy S10 which has the ultrasonic fingerprint scanner and it is a fact that they are slower than the capacitive scanner that I have on the Huawei Y7 Prime 2019.

They feel as slow as the capacitive scanner that we saw with the iPhone 5S which was released in 2013! Add the fact that sometimes they can be fiddly where they need precise placement of your finger to activate and sometimes failing to register at all is annoying.


However, I understand these are first gen optical and ultrasonic fingerprint scanners and it only means that they will become better in the next couple of years. But, the move from a a technology that was working brilliantly to an inferior solution in terms of practicality feels disingenuous at best.

We’re in a situation where we get great capacitive fingerprint scanners and headphone jacks in mid-range to budget phones. Flagship phones have replaced both of these features with subpar solutions.

Until we get a situation where in-display fingerprint scanners are as good as capacitive fingerprint scanners, I’m off the school of thought where I believe it should come back to flagship phones.