It may seem strange, at first glance, to encounter a microphone as an Innovation Awards candidate. After all, the materials that comprise ECMs (electret condenser microphones) have existed since the 1920s, and Bell Laboratories unveiled the first practical ECM, basing it on thin metallized Teflon foil, in 1962. But leave it to Akustica, with the AKU2000, to bring vitality back into a moribund product category.

The core of Akustica's achievement is MEMS (microelectromechanical systems), a technology that to date has seen its broadest use in inkjet print heads, optical switches, DLP (digital-light-processing) engines, accelerometers, gyroscopes, and pressure sensors. Unlike traditional MEMS devices, which require custom thin-film semiconductor techniques, Akustica's AKU2000 employs the metal-dielectric layers of conventional CMOS processes.

ECMs' analog outputs are susceptible to signal corruption from nearby EMI-radiating sources, such as cell phones, LCDs and their backlights, and WiFi transceivers. As a result, engineers must often place them in nonideal locations, to minimize cabling lengths back to the system board, and must also burden the system with the cost of shielding materials. The AKU2000's PDM (pulse-density-modulated) digital output exhibits none of these shortcomings; the device (which integrates an acoustic transducer, analog preamplifier, and fourth-order sigma-delta modulator) is also surface-mountable and, at 4×4×less than 2 mm, squeezes into tight spaces. Although at the moment the cost of the AKU2000 is approximately double that of an ECM, the differential will decrease as MEMS microphones ramp into ever higher production volumes. And if and when Akustica follows through on its promises to meld a microphone with other MEMS-amenable functions on a single device, things will get very interesting.