Engineering
How a MEMS Accelerometer Senses Motion for Smartphones
Quick fact
Modern smartphone MEMS accelerometers can detect accelerations as small as a few milligravities (0.001 g) by measuring changes in capacitance of just a few femtofarads (10^-15 F).
Why this is interesting
Ever wonder how your phone knows to rotate the screen when you tilt it? The answer lies in a microscopic mechanical structure smaller than a grain of sand.