Video doorbells are getting smarter all the time, with two-way talk, animal alerts and even built-in radar tracking. These are the smartest doorbell cameras of them all.

Wearable strain sensors based on poly (viny- lidene fluoride-co-hexafluoropropylene) (PVDF-HFP) reinforced with carbon nanotubes (CNTs) dispersed with Triton surfactant by solvent casting are proposed ...