In order to unlock a dead man's iPhone, a Michigan State University professor helped police by 3D-printing a new finger, supposedly with embedded metal chips to allow for conductivity:
https://www.engadget.com/2016/07/21/police-get-dead-man-s-finger-3d-printed-to-unlock-his-phone/
https://www.engadget.com/2016/07/21/police-get-dead-man-s-finger-3d-printed-to-unlock-his-phone/