Printed electronic labels and stickers are expected to play important role aa remote sensors within the Internet-of-things concept.
It is crucial to couple such technology with standard communication systems that commonly operate at gigahertz frequencies.
Ultra–high-frequency rectification components manufactured in a low-temperature printing process can supply the power to printed electronics with the help of conventional mobile phones.
In 2001, PetronellaNorberg at Acreo Swedish ICT, utilized silicon paste as ink in printing press to produce a functional printed diode, but could not explain how and why, and in addition, the diode only worked up to 1 MHz
With an article published in the Proceedings of the National Academy of Sciences (PNAS), NegarSani, Ph.D. student at Linköping University’s Laboratory of Organic Electronics, Campus Norrköping, has succeeded in explaining a 13 year old mystery – how a printed diode can function in the GHz band. The researchers succeded in developing an all-printed diode operating above 1 GHz, using a combination of Si and NbSi2 microparticles. When a paste containing the transition metal niobium, in the form of niobium silicide, NbSi2, is printed over the silicon paste, nano-thin films (1–2 nm) are formed around the micrometer-sized grains of silicon. Because of a tunnel effects phenomenon in quantum physics, the current between anodes (aluminium) and cathodes (silver and carbon) pass through, but only in one direction.
The diode was integrated with a flexible antenna and a printed electrochromic display indicator to successfully demonstrate remote transfer of signal and power from a standard Global System for Mobile Communications phone to the resulting e-label.