If you are having signal problems, you may some day be able to spray on an antenna to get better signal. Nano spray-on particles could be sprayed on to trees or buildings to transmit signals. This technology is not a spray-on dream of the future but was demonstrated at Solve for X.
Rhett Spencer CTO of Chamtech showed that the spray on antenna on a tree worked better than a standard antenna.
Tesla and Marconi used a copper wire for an antenna, the same technology still used today. Antenna's get hot, meaning it is not efficient. The ChamtTech material is more efficient.
They call it a wireless-antenna made of nana capacitors that charge and discharge very quickly. The signal hops from capacitor to capacitor easily.
After spraying a tree they transmitted data signal to an airplane 14 miles in the sky. He shows how applying it on a standard NFC tag that increased the range from 5 to 700 feet. Tested on iPhone, applied the substance increased the signal 20 DBM. The material transmitted one nautical mile in the water.
They also tested pulling energy out of the atmosphere to power it. ChamTech currently sells a portable "Spray on Antenna Kit" that comes spray cans of material and a manual.