1, I want to know what is the limitation on the making circuit for little device.

For example. if there is very small wifi chip (2mm x 2mm), and if we want to change this chip shape 1cm x 50um,

what is the limitation... 1. quantum size effect? 2. substrate

3. copper lead width 4. solders width

5. or etc...

2. If we want to make device which has the function of GPS tracker it need gps chip and RF chip and CPU chip and Antenna. But if we have to make this device very small, we have to not to use some parts such like gps chip or Rf chip.

What I want to know is What kinds of parts is needed... if we want to make new device which has the only Wifi chip and use Free Wifi zone position data for make someone know its position information

There are alot of free wifi zones. if new device is near by free wifi zone, device contact with wifi and send its wifi position which device is connected to someone who wants to check the device position by e-mail or etc... What kinds of parts is needed... it is more compliacted?