Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi-frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

A capacitive physical quantity sensor includes a first substrate, a movable electrode, a fixed electrode, and a second substrate. An auxiliary electrode is disposed on a portion of the second substrate to face the movable electrode and the auxiliary electrode has a facing area that faces the movable electrode. The facing area in a case where the movable electrode is displaced in one direction is different from the facing area in a case where the movable electrode is displaced in an opposite direction opposite to the one direction. The physical quantity is detected based on a capacitance, which is generated corresponding to the interval between the fixed electrode and the movable electrode, and a capacitance, which is generated corresponding to an interval between the facing area of the movable electrode and the auxiliary electrode.

A method for contextual inference of user activity is disclosed. In one embodiment, an indication of the motion of a pole mounted sensing device comprising at least one motion sensor and a Global Navigation Satellite System (GNSS) receiver configured to at least generate raw GNSS observables is received from the at least one motion sensor. The indication of the motion of the pole mounted sensing device is correlated with an operation defined in a gesture library regarding GNSS data collect by the GNSS receiver at a time when the indication of the motion is detected. The indication and the GNSS data are stored.

A micro-electro-mechanical system (MEMS) package structure and a method for fabricating the MEMS package structure. The MEMS package structure includes a MEMS die (200) and a device wafer (100). A control unit and an interconnection structure (300) are formed in the device wafer (100), and a first contact pad (410) and an input-output connecting member (420) are formed on a first bonding surface (100a) of the device wafer (100). The MEMS die (200) is coupled to the first bonding surface (100a) through a bonding layer (500). The MEMS die (200) includes a closed micro-cavity (220) and a second contact pad (220). The first contact pad (410) is electrically connected to a corresponding second contact pad (220). An opening (510) that exposes the input-output connecting member (420) is formed in the bonding layer (500). The MEMS package structure allows electrical interconnection between the MEMS die (200) and the device wafer (100) with a reduced package size, compared to those produced by existing integration techniques. In addition, function integration ability of the package structure is improved by integrating a plurality of MEMS dies of the same or different structures and functions on the same device wafer.

A sensor includes a MEMS element responsive to acceleration, an analog-to-digital converter coupled to an output of the MEMS element, and a free fall detector coupled to an output of the analog-to-digital converter. The free fall detector is configured to determine whether the sensor is in free fall based on acceleration information received from the analog-to-digital converter. A digital interface is coupled to the analog-to-digital converter and to an output of the free fall detector and is configured to issue an output related to free fall information determined by the free fall detector.

A MEMS device includes a first MEMS sensor associated with a first spatial plane and a second MEMS sensor is associated with a spatial second plane not co-planar with the first spatial plane, wherein the first MEMS sensor is configured to provide a first interrupt and a first data in response to a physical perturbation, wherein the second MEMS sensor is configured to provide a second interrupt and second data in response to the physical perturbation, and a controller configured to receive the first interrupt at a first time and the second interrupt at a second time different from the first time, wherein the controller is configured to determine a latency between the first time and the second time, and wherein the controller is configured to determine motion data in response to the first data, to the second data, and to the latency.

A MEMS accelerometric sensor includes a bearing structure and a suspended region that is made of semiconductor material, mobile with respect to the bearing structure. At least one modulation electrode is fixed to the bearing structure and is biased with an electrical modulation signal including at least one periodic component having a first frequency. At least one variable capacitor is formed by the suspended region and by the modulation electrode in such a way that the suspended region is subjected to an electrostatic force that depends upon the electrical modulation signal. A sensing assembly generates, when the accelerometric sensor is subjected to an acceleration, an electrical sensing signal indicating the position of the suspended region with respect to the bearing structure and includes a frequency-modulated component that is a function of the acceleration and of the first frequency.

A mechanism for reducing stiction in a MEMS device by decreasing surface area between two surfaces that can come into close contact is provided. Reduction in contact surface area is achieved by increasing surface roughness of one or both of the surfaces. The increased roughness is provided by forming a micro-masking layer on a sacrificial layer used in formation of the MEMS device, and then etching the surface of the sacrificial layer. The micro-masking layer can be formed using nanoclusters. When a next portion of the MEMS device is formed on the sacrificial layer, this portion will take on the roughness characteristics imparted on the sacrificial layer by the etch process. The rougher surface decreases the surface area available for contact in the MEMS device and, in turn, decreases the area through which stiction can be imparted.

A vacuum sealed MEMS and CMOS package and a process for making the same may include a capping wafer having a surface with a plurality of first cavities, a first device having a first surface with a second plurality of second cavities, a hermetic seal between the first surface of the first device and the surface of the capping wafer, and a second device having a first surface bonded to a second surface of the first device. The second device is a CMOS device with conductive through vias connecting the first device to a second surface of the second device, and conductive bumps on the second surface of the second device. Conductive bumps connect to the conductive through vias and wherein a plurality of conductive bumps connect to the second device. The hermetic seal forms a plurality of micro chambers between the capping wafer and the first device.

According to one embodiment, a method of manufacturing a device is provided. A amorphous metal layer is formed. A metal layer containing metal and having a crystal plane oriented to a predetermined plane is formed on the amorphous metal layer. A first layer containing semiconductor including silicon, and metal identical to the metal contained in the metal layer is formed on the metal layer. The first layer is changed to a second layer containing a compound of the semiconductor and the metal, the compound having a crystal plane oriented to the predetermined plane. A third layer containing polycrystalline silicon-germanium and having a crystal plane oriented to the predetermined plane is formed on the second layer.