ESPOO, Finland – VTT Technical Research Centre of Finland, a government funded research agency, is claiming it has developed an improved form of silicon MEMS microphone.
VTT has a broad range of expertise in biological, mechanical and electronic technologies at both the component and system level. In the electronics sector it specializes in supporting microelectromechanical system (MEMS) sensors and printed electronics.
Professor Aarne Oja, director of the high performance microsystems program at VTT, showed EE Times a sample of the latest technology that includes four silicon membranes in an integrated die.
"VTT developed MEMS microphones in 2000 and 2003 with a polysilicon membrane but we were a little too soon for the market," he said. With the boom silicon MEMS microphone deployment for smartphone, tablet computer and potential automotive and domestic applications VTT has decided to re-enter the microphone field," Professor Oja said.
Professor Oja declined to reveal much about the device while VTT established its intellectual property protection and begins negotiating with parties. The key benefit of VTT's MEMS microphone is that it has lower noise and higher signal-to-noise ratio (SNR) than available MEMS microphones, he said.
"Conventional microphones are reaching a brick wall in terms of performance." One of the problems is internal noise due to Brownian motion of crystal structure.
While the use of multiple microphone membranes can be used for ambient noise reduction in noise-cancelling headphones and for direction finding to help identify speakers Professor Oja said that was not the key innovation that VTT has made.
MEMS mics are used in a large percentage of modern mobile phones and are being introduced into hearing aids.
The biggest player right now is Knowles, a traditional transducer maker.
Many semi companies are hot on their heels.
Another way of saying the same thing is that it may be able to produce adequate performance in less area of silicon thereby making listening/direction-finding arrays lower cost to produce.
But we need more detail.