MEMS are the Cinderellas of the electronic world. They do a lot of hard work, but get very little recognition.
The tiny chips, their full name is micro-electro-mechanical systems, can sense mechanical motion and convert that motion into electrical signals. “Just about everybody has them in their cellphones,” says Nicholas Yost, electronics technician at GE Global Research. These sensors, accelerometers and gyroscopes can detect the right screen orientation in smartphones, sense motion in Wii controllers, and even deploy airbags in cars.
Modern MEMS switches are the Jetsons version of the bulky mechanical relays in grandfather’s garage. They open and close circuits with just electrostatic force, the same stuff that makes your hair stand on end. “We take an electrical stimulus and make it into a mechanical moving structure,” says Marco Aimi, scientist at GE Global Research.
GE is developing a class of tiny metal MEMS devices that contain relays thinner than a human hair. They are able to switch electrical circuits hundreds to thousands of times per second. “We are using these switches to turn things on and off very quickly,” says Chris Keimel, process development engineer at the GRC. “Ironically, in order to make something faster, you have to make it smaller.”
Here’s why that’s important. Despite their small size, these microscopic relays can handle hundreds of watts, even kilowatts of power. The could help reduce waste heat and power consumption in everything from mobile phones to medical devices, and improve power management and protection systems for industrial and aviation applications
Keimel and Yost recently took filmmakers Gavin Free and Dan Gruchy into their lab to record MEMS in action. Free and Gruchy, who run the wildly popular You Tube show The Slow Mo Guys, brought with them their Phantom Flex digital camera, which can record 25,000 frames per second. They filmed how a MEMS-controlled Christmas tree LED flicked on and off thousands of times during the relative eternity it took a corn kernel to pop.