Differential capacitive sensor and method of making same

A method of fabricating a Micro Electro-Mechanical System (MEMS) sensor comprising:

• providing a substrate;
• forming a first static conductive layer on said substrate to include a first actuation electrode and a first sensing electrode electrically isolated from said first actuation electrode;
• forming a first sacrificial layer on said first conductive layer;
• forming a movable element on said first sacrificial layer adapted for motion relative to a rotational axis offset between first and second ends thereof to form a first section between said rotational axis and said first end and a second section between said rotational axis and said second end, said first section including an extended portion spaced away from said rotational axis at a distance approximately equivalent to a length of said second section;
• forming a second sacrificial layer on said movable element;
• forming a second static conductive layer on said second sacrificial layer to include a second actuation electrode and a second sensing electrode electrically isolated from said second actuation electrode;
• and
• selectively removing said first and second sacrificial layers such that said first and second conductive layers are spaced away from said movable element, and said first and second conductive layers being formed such that said first and second actuation electrodes oppose said extended portion of said movable element.

A Micro Electro-Mechanical System (MEMS) sensor comprising:

• a movable element adapted for motion relative to a rotational axis offset between first and second ends thereof to form a first section between said rotational axis and said first end and a second section between said rotational axis and said second end, said first section including an extended portion spaced away from said rotational axis at a distance approximately equivalent to a length of said second section, and said movable element including a first surface and a second surface;
• a first static conductive layer spaced away from said first surface of said moveable element, said first conductive layer including a first actuation electrode, a first sensing electrode, and a third sensing electrode;
• and
• a second static conductive layer spaced away from said second surface of said moveable element, said second conductive layer including a second actuation electrode, a second sensing electrode and a fourth sensing electrode, said first and second actuation electrodes opposing said extended portion, said first and second sensing electrodes opposing said first section, said third and fourth electrodes opposing said second section, and each of said first, second, third, and fourth sensing electrodes having a surface area in a range of twenty-five to thirty-five percent of an overall surface area of said movable element.