Enterprising engineers build world's smallest microphone

January 5, 2012 by Bob Yirka report

(PhysOrg.com) -- Imagine what you could do with a microphone so small, it’s almost invisible to the naked eye. Clearly there would be practical uses, such as in creating hearing aids that no one would notice, or devices that could be applied with a mild adhesive on or near the mouth or jaw bone to allow for instant communications via Bluetooth technology; but what of other more clever applications, such as always-on implanted heart monitors or super-sensitive devices that could be used as hidden monitors to detect intruders or the presence of others for those with vision impairments.

All of these things and more are likely on the way as research engineers continue to invent new ways to build ever smaller microphones. The new record holders are Bahram Azizollah Ganji, of Noshirvani University of Technology, in Iran, who has built a microphone that is just a half mm square, or put another way, just 700 square microns, and Bosch Sensortec GmbH, who apparently have made one that is roughly the same size. Either way, these microphones are tiny; so tiny most people wouldn’t notice them at all unless one was sitting alone on a pure white backdrop. Perhaps just as important, the tiny new microphones appear to be both highly sensitive and tiny power consumers.

The tiny microphone market is huge, with some 685 million of them in various sizes and shapes sold in 2010 alone. Currently they are used in phones, electronic notepads, research equipment, computers, cameras, and a myriad of other devices (including spy equipment no doubt). But the rush is on to make them ever smaller, which should not only allow for smaller sized devices such as cell phones, but new uses for them altogether. Imagine a microphone placed strategically on either side of a person’s mouth, allowing someone listing to them on a dual speaker phone to hear their voice in stereo, or what if such microphones were to be embedded into the very construction elements of buildings, allowing people to speak to one another from their offices without having to use a phone at all, assuming they were all connected to a voice activated computer system of course. The possibilities seem almost endless.

Some industry analysts, such as the trend watchers at IHS iSuppli, say that the tiny market has more than doubled in just the past year, and expect such growth will not just continue, but grow. Thus, the development of ever tinier microphones is not just cool, it’s likely to be extremely lucrative.

Explore further: Novel Ear-like Dual Microphone System Tunes Out Background Noise In Cellphones

More information:
via ISNA

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5 / 5 (2) Jan 05, 2012
Very interesting, I could finally interview the bugs in my garden :D
1.9 / 5 (9) Jan 05, 2012
The ants in my house can finally put on that rock show they have been wanting for so long.

Also, I noticed that not a single mention was made of the applications in super secret awesome spy equipment.
5 / 5 (1) Jan 05, 2012
An interesting feature of miniature microphones is their very wide bandwidth, with these you can effectively detect high-frequency ultrasound in the air.
5 / 5 (1) Jan 05, 2012
sounds interesting,but i think 0.5mm² are not close to 700 square microns. "who has built a microphone that is just a half mm square, or put another way, just 700 square microns "

half mm² = 0.5*10^-6 m² and 700 square microns = 700*(1*10-6)² = 7*10^-10m²
5 / 5 (1) Jan 05, 2012
700 square microns in mm squared equals 0.0007 mm^2 not even close to 0.5mm^2. "...who has built a microphone that is just a half mm square, or put another way, just 700 square microns...".

700 microns are close to 0.5mm but not in squared units.
5 / 5 (1) Jan 05, 2012
I built a microphone almost that small using piezo pickups, you can cut them with a pair of scissors, the kind that are on a dime sized or quarter sized brass substrate. One side cuts clean, the other side shatters into very small pieces but with the silver paste still intact. It worked, not very noise free but it was just a quickie experiment. That was me and a genius in Jerusalem, Ray Sdudero, RIP.
5 / 5 (1) Jan 05, 2012
Interesting to read that this was developed in Iran. With all the sanctions they get it's impressive that researchers there can still make these breakthroughs. If Iran's relationship with the West was better they'd probably be able to accomplish much more.
2 / 5 (4) Jan 05, 2012
Very interesting, I could finally interview the bugs in my garden :D
Very interesting, Big Brother could finally enjoy the bugs in my bedroom..
1 / 5 (1) Jan 05, 2012
Jeeze pretty soon we wont need ears or eyes, the computers will see hear think and act for you. When do we die and the computers live though.
2.6 / 5 (5) Jan 06, 2012
Soon we won't be able to tell if/when a person is bugged and recording our every word. Computers will have invisible microphones and cameras in them that will invade our every space. Perhaps they'll even incorporate them into clothing so even the clothes we wear will be telling tales on us...
Of course, this is just my paranoid rant; I hope I am wrong.

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