A sensor apparatus includes a base, a tap, a channel, and a gate. The tap is adjacent the base and electrically coupled to the base. The channel is between the tap and the base. The gate is adjacent the channel and electrically coupled to the channel. The gate is separated from the channel by a gap. At least a portion of a charge flow in the channel is substantially parallel or antiparallel to an electric field between the gate and the channel. A triode capacitor system includes a channel region, a gate region, and a processor. The gate region is separated from the channel region by a gap. The processor is coupled to a base contact, a tap contact, and a gate contact and configured to measure a distance of the gap based on a potential difference between the base contact and the tap contact.

A semiconductor structure includes a substrate, a sensing device disposed over the substrate and including a plurality of protruding members protruded from the sensing device; a sensing structure disposed adjacent to the sensing device and including a plurality of sensing electrodes protruded from the sensing structure towards the sensing device; and an actuating structure disposed adjacent to the sensing device and configured to provide an electrostatic force on the sensing device based on a feedback from the sensing structure. Further, a method of manufacturing the semiconductor structure is also disclosed.

A MEMS sensor comprising preloaded suspension springs and a method for mechanically preloading suspension springs of a MEMS sensor are described. The MEMS sensor comprises a MEMS support structure; a plurality of suspension springs connected to said support structure; and, a proof mass flexibly suspended by said suspension springs; wherein at least one of said suspension springs is mechanically preloaded with a compressive force for reducing the natural frequency of said proof mass.

A vibrating device includes: a base body containing mobile ions; a movable member disposed facing and spaced apart from the base body; and a conductor section disposed so as to cover at least a portion of the movable member. A first voltage whose potential periodically changes based on a reference potential is applied to the movable member. A second voltage that is at the reference potential when time-averaged is applied to the conductor section. The second voltage is constant at the reference potential.

The purpose of the present invention is to provide a method for manufacturing a three-dimensionally structured member which can be made by a simpler process. The method for manufacturing a three-dimensionally structured member includes shaping a flat plate-shaped base member to produce a three-dimensionally structured member having a plurality of sections that are different from one another in thickness. The manufacturing method comprises: a mask formation step for forming a mask over the whole of at least one main surface of the base member; a mask removal step for removing a part of the mask; and an etching step for etching an exposed part of the base member, wherein a combination of the mask removal step and the etching step is performed on the mask and the base member that correspond to each of the plurality of sections of the three-dimensionally structured member, in the order from thinnest to the thickest of thicknesses of the three-dimensionally structured members.

A capacitive accelerometer includes a proof mass, first and second fixed capacitive electrodes, and a DC biasing element arranged to apply a DC voltage (V.sub.B) to the proof mass based on a threshold acceleration value. A first closed loop circuit is arranged to detect a signal resulting from displacement of the proof mass and control the pulse width modulation signal generator to apply the first and second drive signals V.sub.1, V.sub.2 with a variable mark:space ratio. A second closed loop circuit keeps the mark:space ratio constant and to change the magnitude, V.sub.B, of the DC voltage applied to the proof mass by the DC biasing element so as to provide a net electrostatic restoring force on the proof mass for balancing the inertial force of the applied acceleration and maintaining the proof mass at a null position, when the applied acceleration is greater than a threshold acceleration value.

Provided is a sensor that is highly accurate while ensuring reduced power consumption. A sensor is an electronic circuit that includes a sensor element, an analog filter, an A/D converter, and first and second electronic circuit. The analog filter filters a waveform that includes a sensor signal from the sensor element and noise based on a servo signal. The A/D converter converts the waveform filtered by the analog filter into a first digital signal. The first electronic circuit includes a digital filter and acquires a second digital signal by performing signal processing including at least a filtering process on the servo signal by using the digital filter. The second electronic circuit acquires a third digital signal by subtracting the second digital signal from the first digital signal. A setting for the signal processing for acquiring the second digital signal is changed on the basis of the third digital signal.

A resonant mechanical structure, such as one for use in a torsional oscillator MEMS accelerometer that includes a mounting substrate and a reference mass configured to move within a reference mass plane, the resonant mechanical structure being connected to the mounting structure and the reference mass, and the resonant mechanical structure including a body, a center of mass, and an aperture, wherein the aperture is surrounded and defined by the body, and wherein the body includes a first mass portion and a second mass portion that are configured to oscillate about an oscillation axis located within the reference mass plane, wherein the center of mass is located on the oscillation axis, and wherein a movement of the reference mass within the reference mass plane varies a moment of inertia of the body while the center of mass of the body remains located on the oscillation axis.

A method for closed loop operation of a capacitive accelerometer includes applying a first drive signal V.sub.1 to a first fixed capacitive electrode and a second drive signal V.sub.2 to a second fixed capacitive electrode the first and second drive signals each having a periodic waveform varying in amplitude between zero and a maximum value V.sub.ref and sensing a displacement of the proof mass and applying pulse width modulation to the first and second drive signals with a constant frequency f.sub.mod and a variable mark/space ratio. The method also includes applying a voltage offset V.sub.ref/2 to the proof mass and applying the pulse width modulation such that the first and second drive signals have a waveform that varies so that when either one of the first and second drive signals is at V.sub.ref or zero the other drive voltage is at V.sub.ref/2.

The invention discloses a MEMS sensor detection device and a MEMS sensor system, wherein the MEMS sensor detection device comprises: a readout circuit used for analog signal processing of the output signal of the MEMS sensor to generate detection voltage; a cancellation voltage generation circuit used for generating a gravity cancellation voltage according to the detection voltage, wherein the gravity cancellation voltage and the gravity acceleration are in a positive proportional relationship; a selection circuit used for selecting the detection voltage output in a feedback phase and selecting the gravity cancellation voltage output in a gravity cancellation phase, wherein in one detection period, the feedback phase is located after the gravity cancellation phase; and a feedback circuit used for generating a feedback voltage according to the output voltage of the selection circuit, wherein the feedback voltage is in a positive proportional relationship with the output voltage of the selection circuit. The MEMS sensor detection device and the MEMS sensor system disclosed by the invention can cancel the influence of gravity acceleration and improve the sensitivity of the MEMS sensor system.