Binghamton University researchers want to improve capacitive sensing

Binghamton University scientists want to improve sensor technology critical to billions of devices made every year.

With a three-year, $359,958 grant from the National Science Foundation that begins in September, they will start by making a high-performance sensor and applying it to hearing aids.

“This [grant] allows us to explore a new sensing mechanism that can revolutionize capacitive sensing by addressing the severe limitation of limited range of motion. This could lead to devices with better sensitivity and functionality,” said Principal Investigator Sherry Towfighian, an Assistant Professor of mechanical engineering within the Thomas J. Watson School of Engineering and Applied Science about the grant that will help fund, “A New Approach to Capacitive Sensing: Repulsive Sensors.”

Distinguished Professor and Chair of the Mechanical Engineering Department Ron Miles is a co-principal investigator on the project.

Capacitive sensing uses differences in electrical storage capacity of two electrodes, one fixed and one movable, to detect physical quantities. The technology can measure position, humidity, fluid levels, acceleration or noise in devices like accelerometers, gyroscopes, touchscreens, proximity sensors, and microphones. The miniature sensors and devices are Micro-Electro-Mechanical Systems or “MEMS.”

All hearing aids contain a miniature microphone (often two), a signal processor/filter to compensate for hearing loss, a small amplifier, and a receiver which sends amplified sound into the ear, much like an ear bud, according to Miles.

While digital signal processing technology has produced significant performance improvements in hearing aids over the past decade, the ability to understand speech in noisy environments is still hampered by limitations in microphone technology with regard to microphone self-noise and directionality.

“This research will lead to new ways to sense sound that will overcome many performance limitations,” Miles said. “While this project uses microphones as an application area for capacitive sensing research, the intent is to overcome design constraints that plague all capacitive sensing devices.”

“MEMS microphones have the potential of providing significant performance improvements in hearing aids,” Towfighian said in the grant description. “However, they have not yet demonstrated sufficient performance for this demanding application in general. If successful, this research will lead to more sensitive MEMS microphones for hearing aids and will have a tremendous impact on the lives of hearing impaired.”

Along with the hardware research, a portion of the grant will be used to fund internship experiences for undergraduate students in MEMS and acoustics at Binghamton. Run primarily by graduate students, interns will become familiar with modeling, fabricating, and testing MEMS microphones with the new sensing system. The skills are in demand for research jobs.

“Internships can trigger deeper interest in undergraduate students to continue to graduate studies,” Towfighian said. “The experiences can train students to solve challenging research questions and enhance their analytical skills which makes them more marketable after Binghamton too.”

The research also aligns with the goals of the Transdisciplinary Area of Excellence (TAE) in Health Sciences from the Binghamton University Strategic Plan also known as the, “Road Map.” There are five Transdisciplinary Areas of Excellence at Binghamton:

• Citizenship, Rights, and Cultural Belonging
  
• Health Sciences
  
• Material and Visual Worlds
  
• Smart Energy
  
• Sustainable Communities
  

Run through the Office of the Provost, each TAE, addresses critical social, scientific, technological, economic, cultural, and policy issues. For the TAE in Health Science in particular, Binghamton seeks to, “have a positive impact on the quality, availability and affordability of American healthcare. This area of excellence will help to ensure that the latest innovations in healthcare travel speedily from lab bench to bedside,” according to the University’s official description.