[eternalvision]

That's cool, but was thinking of something along the lines of what a PhD EE might conceive. Small chips out of sight using ultrasonic waves to create a detailed real-time 3d-map of a physical space, for instance.

[bigiain]

Ahhh - so not quite a "camera", but have you seen this:

http://people.csail.mit.edu/fadel/wivi/design.html

https://www.businessinsider.com.au/wifi-camera-sees-through-...

https://www.engadget.com/2017/06/19/researchers-map-a-buildi...