Improved silicon MEMS microphone targets smartphones and tablets

May 30, 2012 // By Peter Clarke
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.

"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," siad Professor Aarne Oja, director of the high performance microsystems program at VTT.

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.