Transparent and self-activated harmonic sensor using integrated graphene antennas and circuits

We propose a new paradigm of transparent, flexible, and self-powered radio-frequency (RF) harmonic sensor based on all-graphene antenna and frequency multiplier/sensor. The multilayered-graphene antenna receives fundamental tone at C band and retransmits the sensed signal (harmonic tone) at X band, thus allowing high-performance sensing in a severe interference/clutter background. The frequency multiplier is built by graphene transistors, with the conversion gain being chemically sensitive to exposed gas/molecule/chemical dopants. This all-graphene system may benefit various wireless sensing applications, such as smart contact lens and microscope slides.