With cell phones and implantable medical sensors smaller and lighter than ever, the antennas receiving signals must shrink as well. Enter foldable antennas from Osaka University in Japan. A team there recently printed what they call silver nanowire ink — a paste composed of 100-nanometer-wide wires, jumbled together — onto paper made with fibers slightly wider than common paper.
Folding or unfolding the paper tunes the wires to a range of frequencies. The highly sensitive components could be squeezed into narrower spaces within the tiniest electronic devices, making the antennas versatile enough to be applied to future foldable electronics. The pair of origami cranes above shows off the folded antenna-paper by lighting up an LED.
[This article originally appeared in print as "Nano Antennas for Tiny Machines."]