A micro-machined acceleration sensing apparatus includes a piezoelectric substrate that functions as a propagation medium. A diaphragm is configured upon the substrate, wherein the diaphragm is etched to form one or more etched cavities. Sensing elements are formed on the diaphragm, wherein a first sensing element among the sensing elements is located on a top of the diaphragm, a second sensing element among the sensing elements is located on a side of the diaphragm, and a third sensing element among the sensing elements is located at a crystallography different orientation with respect to the first and second sensing elements, such that the substrate, the diaphragm and the plurality of sensing elements comprise a micro-machined acceleration sensing apparatus thereof that is clamped at one end of the substrate to an object under an acceleration and submitted to a force at the free end of the substrate to provide signals indicative of acceleration.