Iran's Babol Noshirvani University of Technology reports that one of its faculty members, Bahram Azizollah Ganji, has built a 0.5 mm squared capacitor microphone that can be used in building tiny and "invisible" hearing aids.
The device, which includes the same MEMs, or micro-electro-mechanical systems, approach as the microphones currently used in portable devices, could claim the world record. (PhysOrg.com reports that Bosch Sensortec GmbH has also made a microphone that is roughly the same size.)
While no specs have been revealed, the tiny microphone is described as highly sensitive, low-cost, with low power requirements.
Most of the microphones used in portable devices today, like hearing aids and smartphones, range from a few millimeters squared to the size of a watch battery. But demand for even smaller microphones is taking off as new potential applications are uncovered, including smartphones and Bluetooth headsets with better form factors.
Tiny microphones can also be used for medical purposes, such as next-generation hearing aids and always-on, non-intrusive heart monitors.
With a little imagination, there is no end to the opportunities for invisible microphones, including "smart" buildings, defense systems, and a bevy of spy gadgets like pens and watches.