Stiction

Updated September 10, 2011

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New for August 2011! When a MEMS switch gets stuck in the closed position this is called stiction. It's a portmanteau which originally meant "static friction". When static friction is overcome, something begins to move, like a car on bald tires sliding down an icy hill with the wheels all locked by a panicked driver. The MEMS crew adopted the word and bastardized it, in this case it means "stuck closed". This phenomenon is the result of miss-handling a switch, a typical event that might cause stiction is hot switching beyond the rated power level. Over the life of the switch, there will be charge buildup which eventually sticks the switch forever.

Stiction has been the major reliability concern since the dawn of the MEMS RF switch. Many MEMS manufacturers claim to have this all figured out, often advertising 50 billion switch cycles as an important metric. This type of measurement takes many months because MEMS switches are so slow (10 us or more to change state). You could do 60 billion switch cycles in a few seconds with a PIN diode switch...

Below is a link to a song that might have been written with MEMS switches in mind, by everyone's favorite anarchist band, Chumbawamba. MEMS switches get knocked down, but they get up again, until they get knocked down for good. Oh, Danny Boy, Danny Boy...

Chumbawamba's Tub Thumping on Letterman

Just replace the lines "pissing the night away" with "pissing my career away..."