The Fraunhofer FEP institute in Germany first unveiled its bi-directional OLED microdisplays in 2012 with the novel idea of embedding photo detectors between the OLED pixels. Since then the instituted demonstrated its second-generation microdisplay that supported a resolution of 800x600 (SVGA), up from VGA in the first generation prototypes.

Bi-directional OLED microdisplay (Fraunfhoer FEP, 2017)

The Fraunhofer FEP now announced that it developed a new generation of these displays, that employ an extra-think encapsulation layer, which can turn these new displays into fingerprint sensors. The idea is that the OLED display illuminates the fingers and then the reflected light is used to detect and analyze the fingerprint with excellent accuracy.

The prototype sensor has a native resolution of 1,600 DPI - which is three times more than typically required by the FBI. This allows the identification even of smallest sweat pores beside the typical papillary lines, which can be used to increase the security.