How microscopic machines can fail in the blink of an eye

phys.org ^ | November 30, 2018, | National Institute of Standards and Technology

[BenLurkin]

How long can tiny gears and other microscopic moving parts last before they wear out? What are the warning signs that these components are about to fail, which can happen in just a few tenths of a second?

[R]esearchers at the National Institute of Standards and Technology (NIST) have developed a method for more quickly tracking microelectromechanical systems (MEMS) as they work and, just as importantly, as they stop working.

[U]sing this method for microscopic failure analysis, researchers and manufacturers could improve the reliability of the MEMS components that they are developing, ranging from miniature robots and drones to tiny forceps for eye surgery and sensors to detect trace amounts of toxic chemicals.

Over the past decade, researchers at the National Institute of Standards and Technology (NIST) have measured the motion and interactions between MEMS components. In their newest work, the scientists succeeded in making these measurements a hundred times faster, on the scale of thousandths, rather than tenths, of a second.

The faster time scale enabled the researchers to resolve fine details of the transient and erratic motions that may occur before and during the failure of MEMS. The faster measurements also allowed repetitive testing—necessary for assessing the durability of the miniature mechanical systems—to be conducted more quickly. The NIST researchers, including Samuel Stavis and Craig Copeland, described their work in the Journal of Microelectromechanical Systems.

As in their previous work, the team labeled the MEMS components with fluorescent particles to track their motion. Using optical microscopes and sensitive cameras to view and image the light-emitting particles, the researchers tracked displacements as small as a few billionths of a meter and rotations as tiny as several millionths of a radian. One microradian is the angle corresponding to an arc of about 10 meters along the circumference of the earth.

[MV=PY]

Wow, that’s cool!

Thanks for posting.

[dhs12345]

Knowing process variability is the trick. Cpk re six Sigma.

[dhs12345]

This presumes that the device is designed correctly in the first place.

[Jagman]

Could you imagine a MEMS car: your warranty is for six minutes or six centimeters, whichever comes first!

[jim35]

There are microscopic machines???

[dhs12345]

Sorry for the multiple post: this is cool stuff. A company that I worked for a few years ago was working with their semiconductor process to fabricate MEMS devices. The processes for fabricating chips is perfect for making very small devices.