microelectromechanical systems (MEMS) gyroscopes, which are vibrating structure gyroscopes.
a vibrating object tends to continue vibrating in the same plane even if its support rotates. The Coriolis effect causes the object to exert a force on its support. by measuring this force the rate of rotation can be determined.
When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum.
source: wikipedia