So I thinkkk Uno was able to get info from Lorenzo on Chapter 10 where he was left alone with the laptop using the microchip! After that he probably stuck it in his mouth and attached it to the cigar that Lorenzo was smoking. That could be the reason why Lorenzo noticed the bitter taste it in connection with the flashback on Chapter 11, where the the long-haired techy guy said how it would taste. This meant that the microchip was transferred into Lorenzo's mouth then.
And Uno got it back when he kissed him-thoroughly (Chapter 11). I am assuming that it was necessary for Uno to wait until Lorenzo to walk passed the metal detector just to be sure that he can get it back safely (from ML's mouth) and without causing an alarm.
Thank you for the explanation! I'm wondering, any ideas on how the chip wasn't swallowed by accident and how Lorenzo didn't notice the chip if it had been in his mouth for a short period of time? I'm assuming that is the only way the chip had gone unnoticed. Did Uno not have to go through security though on the way up to the secret area? I don't recall Uno mentioning going through security to get into the building.

Guys help I didn’t understand what happened,can someone explain to me?? I’m really confused about all that chip thing and everything!