If I understand this correctly, this is a paper about 3D printing physical objects, with no electronics, that send information over wifi.
This is magic.
@ajroach42 The same technique can be used (probably is being used) to turn your wifi into passive radar, revealing location & activity information about everyone in the house to a snooper outside.
@firstname.lastname@example.org yep. I read about that a few years back.
Also magic, but pretty scary magic.