With the arrival of Face ID in 2017, the Touch ID fingerprint sensor almost disappeared from the iPhone range.
Touch ID, several patent filings since 2013
However, since 2013 Apple has already filed several patents for the integration of Touch ID under the smartphone screen, but many technical challenges remain for mass production: energy consumption, size of the capture area, modulus thickness and lamination process strength, among others.
Touch ID, health goal?
Proof that the brand is still working on the subject, another patent was recently granted to Apple. The technology described combines a short-wave infrared system and an optical imaging system which could have functions other than fingerprint recognition alone. The document indeed mentions the determination of venous patterns, the measurement of blood oxygenation, pulse, or even the presence of gloves and humidity.
According to news aggregator "eyes1122" from the Korean blog Naver, industry sources expect Touch ID to arrive only two or three years after Face ID itself was hidden under the screen, i.e. 2026 at the earliest. Source: macrumors