The invention of a tiny microphone by Ron Miles, a professor in the mechanical engineering department, may be the key component to the next generation of hearing aids to help the hearing impaired.
“What we’ve done is created these little tiny microphone diaphragms that are directional to sound, so if sound comes from certain directions they will respond, but if sound comes from other directions it won’t respond,” Miles said.
The diaphragm, the key part of the new microphone technology, is the tiny membrane found inside all microphones that responds to the small fluctuations in air pressure produced by sound waves. Miles’ diaphragms, however, are different than those used by traditional microphones because they are created using a special silicon microfabrication process.
“We use silicon wafers; it’s basically the same fabrication process that you use to make integrated circuits and electronic gadgets, but we’re making microphone diaphragms with that technology,” Miles said. “The diaphragms are about 1 mm wide and 3 mm long, so because we’re using that fancy fabrication technology, we can incorporate all kinds of structural details into these diaphragms and design them really accurately and fabricate them the way we want. It’s hard to make this kind of thing unless you use that type of fabrication technology.”
According to Miles, life can be frustrating for hearing-aid users in noisy places, where the excessive background noise makes holding a conversation nearly impossible.
“One way of helping solve that problem is to have the microphone on the hearing aids respond best to the sound coming from the person you’re trying to talk to and help get rid of the sound coming from all around you,” Miles said. “Our microphone is ideal for that.”
Inspiration for this project came from studying the ways that flies not only hear, but navigate through use of their hearing capabilities.
“So in these really tiny flies, they’re incredibly good at localizing sound because their ears are very directional, and doing it in a really tiny thing is difficult; we’ve been borrowing these ideas from the fly,” Miles said.
Miles noted that this technology has applications beyond just improving hearing aids for the hard of hearing, including surveillance technology, voice-activated controls in cars, speech-to-text technology and even cell phones.
“Some cell phones have multiple microphones, like the newest iPhone actually has three microphones, and it’s possible to utilize a directional microphone instead of having that array of microphones,” Miles said.
Funding for this project came in large part from Research Foundation for SUNY’s Technology Accelerator Fund, whose grant of $100,000 was matched by Binghamton University.
“The SUNY Technology Accelerator Fund (“TAF”) provides funding to support the advancement of SUNY technologies from the lab to the marketplace. TAF’s strategic objective is to facilitate the transfer of SUNY-developed technology and public availability of promising new technologies in an expeditious and effective manner,” wrote Peter M. Taubkin, director of External Relations and Corporate Communications for the Research Foundation for SUNY, in an email. “TAF aims to identify opportunities where small investments will make a significant impact on making SUNY technologies available to the public. TAF was launched during the summer of 2011 and has successfully funded projects across the SUNY system to advance them toward commercial readiness.”
According to Taubkin, TAF proposals are evaluated based on the availability of intellectual property protection, marketability, commercial potential, cost sharing opportunities on campus, feasibility and the potential breadth of impact of the new technology.
“Dr. Miles’ proposal met the eligibility criteria and his technology demonstrated superior commercialization potential,” Taubkin wrote.
Miles said that the TAF funding was crucial for his project to get to the later stages of marketability.
“The basic research for creating this has basically been done, and that was funded mostly by National Institute of Health to do the basic research to create the microphones,” Miles said. “Then the question is, how do you transition this to the marketplace? This Technology Accelerator Fund has enabled us to develop more prototypes and to fine-tune these things, and do a little bit more of the development work to make these easier to market to companies.”
It won’t be long before this technology is licensed and incorporated into hearing aids. According to Miles, his team has acquired ten patents already, with around another ten patents pending, and several companies have already expressed interest in licensing this technology, although he was not at liberty to say which companies.
Miles also emphasized the large breadth of the work, adding that a lot went into this project from start to finish.
“We do the whole thing, in that we are actually creating an entire device, an entire system, that contains the mechanical parts, the acoustic sensing, the packaging and the electronics,” Miles said. “So creating the entire system involves a lot of different disciplines, so the work is very interdisciplinary.”
Due to the fact that the chips are made in such small batches, any small problem encountered by Miles’ team proved to be a major setback. According to Miles, it takes dozens of steps to fabricate the silicon wafers, and problems with chemical contamination or malfunctioning equipment may not be detected until weeks into the fabrication process.
Brandon Sheiner, a junior majoring in mechanical engineering, worked with Miles on this project, helping him build apparatuses that allow him to test various parts of the technology and building some of the casings for the micro-chips in the microphones.
“Working with Dr. Miles has been the most fun and best learning experience I have ever had,” Sheiner wrote in an email. “He is a genius but more importantly a great guy and a fantastic role model. I look forward to continuing my research with him and hope to one day have the opportunity to ask him for advice on my own inventions.”