New way to make micro-sensors may revolutionize future of electronics

Researchers at Binghamton University, State University of New York researchers have found a way to improve the performance of tiny sensors that could have wide-reaching implications for electronic devices we use every day.

The MEMS (microelectromechanical systems), which are microscopic devices with moving parts that are often produced in the same way as electronics.

The Binghamton team found that combining two methods for electrostatic actuation-parallel-plate and levitation actuators-led to a predictable linearity that neither of these systems offered on its own.

This research is funded by a grant from the National Science Foundation by Dr. Mark Pallay under the supervision of Principal Investigator Shahrzad (Sherry) Towfighian and Co-Principal Investigator Ronald N. Miles, associate professor and distinguished professor of mechanical engineering, respectively.

The team's findings could be revolutionary for microphone manufacturing, because this is a signal that can be boosted by the issue of noise. More than 2 billion microphones are made around the world each year.

"The electronic noise is really hard to get rid of," Miles said. "You hear this hiss in the background. When you make really small microphones-which is what we want to do-the noise is a bigger and bigger issue. the noise down. "

Towfighian, who has studied MEMS extensively, explained that actuators in the micro-devices are normally only two with a gap between. Those plates close and the device activates when it receives a certain voltage.

It is difficult to fine-tune that kind of actuator, but adding two electrodes on the sides of the plates makes it easier than ever before.

"Combining the two systems, we can get rid of nonlinearity," she said. "If you give it some voltage, it stands at some distance and maintains that over a wide range of motion."

Miles said that predictability is crucial when building actuators for microphones, which have been the focus of his recent research.

"In a sensor, life is much easier if it moves one unit and the output voltage increases in one unit, or something in proportion as you go," he said. "In an actuator, you're trying to push things, so if you're giving it as much as you like, you want to go to it.

"It's like if you had a ruler where you had these things in your mind." "It's a massive headache."

When the Binghamton researchers began their study, they did not know that it would be a good idea.

"The magic-the dumb luck-is that the nonlinearities cancel each other out," Miles said. "They tend to be in opposite directions, we're able to show a significant range, they're linear.

"By having both of these electrode configurations, it is possible to use different forms of design with a different parallel design. With this, there are more electrodes and you get much more control over the design. "

In addition to the possibilities for the manufacture-making of smaller, better and cheaper-Towfighian sees how the new actuator design can be used in her line of study, which includes gyroscopes, accelerometers, pressure sensors and other kinds of switches.

"We showed this concept at a basic level, but it has wide applications," she said. "It can improve the function of many devices, so the impact could be huge."

The study, titled "Merging parallel-plate and levitation actuators to enable linearity and tunability in electrostatic MEMS," was published in The Journal of Applied Physics.