593results about "Fluid pressure measurement using piezo-electric devices" patented technology

A disposable pressure sensor includes a substrate and a pressure diaphragm formed upon the substrate. A sensor coil can be provided, comprising a capacitor and an inductor formed on the substrate and surrounded by the pressure diaphragm. The ferrite core is located proximate to the sensor coil, such that when the pressure diaphragm is exposed to a pressure, the diaphragm moves close to the inductor or the capacitor, thereby resulting in a change in the capacitor or the inductor and an indication of pressure. The capacitor can be implanted as an adjustable, trimmable or variable capacitor. The inductor may also be provided as an adjustable or variable inductor and can include the use of a variable capacitor and a PVDF based piezoelectric transducer. When the PVDF layer is under pressure, it can generate an electric field across the interdigital transducer and transmit a signal thereof through an antenna.

A fluid pressure sensor for a lead or catheter intended for placement in a living organism, such as a human heart, includes a rigid annular or tubular supporting structure and a piezoelectric element disposed on at least a portion of the outer surface thereof. The piezoelectric element delivers an electrical signal when subjected to a pressure variation, and exhibits circumferential sensitivity. The rigidity of the sensor is defined to satisfy predetermined criteria to ensure that the sensor, when sensing pressure transferred to the sensor through an on-growth of tissue on the sensor, which is at least 90% of the signal which the sensor would emit without the on-growth.

A method and apparatus are described for fabricating an exposed backside pressure sensor (30) which protects interior electrical components (37) formed on a topside surface of a pressure sensor transducer die (31) from corrosive particles using a protective gel layer (38) and molding compound (39), but which vents a piezoresistive transducer sensor diaphragm (33) formed on a backside of the pressure sensor transducer die (31) through a vent hole (42) formed in an exposed die flag (36), enabling the sensor diaphragm (33) to directly sense pressure variations without the influence of a protective gel.

A pressure sensor includes: a supporting body which has an opening; a pressure detecting portion which includes a supporting film provided on the supporting body and having a diaphragm portion closing the opening, and a piezoelectric body provided on the diaphragm portion and deflecting to output an electric signal; a frame body which has, on the pressure detecting portion, a cylindrical cavity along a film thickness direction of the supporting film, and is formed, in plan view when viewed from the film thickness direction of the supporting film, at a position where a cylindrical inner peripheral wall of the cavity overlaps with the opening, or outside of the opening; a sealing film which closes the frame body; and a silicone oil which is filled in an inner space formed of the cylindrical inner peripheral wall of the cavity, the sealing film, and the pressure detecting portion.

The present invention is directed to an apparatus and method for a measurement system for the testing of transducers, and more particularly to the testing of piezoelectric transducers. The measurement system includes a transducer, a feedback amplifier coupled to the transducer and a signal processing circuit coupled to the output of the amplifier. The method of testing the transducer includes coupling the test signal to the transducer, disabling the amplifier, and measuring the response of the transducer to the test signal with the test processing circuit. The circuit itself used for performing this method includes a piezoelectric transducer, an amplifier, including a feed-back circuit coupled to the amplifier for amplifying the output of the transducer, a power source coupled to the amplifier, a signal source generating a test signal having a frequency spectrum at least overlapping the self resonant frequency of the transducer coupled to the transducer, and a switch coupled to the amplifier capable of disabling the amplifier.

In a pressure sensor A according to the presenting invention, a piezoelectric element B formed by a thin film of aluminium nitride is mounted on a base material C of an insulating material, and output electrodes D and E and output lead wires F and G which transmit a signal detected by the piezoelectric element B are mounted on the side of the base material C. The pressure sensor A is directly mounted on a cylinder head e of an internal combustion engine, or is mounted on the outer surface of a heater L which is secured at the free end of a glow plug K, whereby it is disposed to face a combustion chamber h. A combustion pressure or oscillations during the operation of the engine can be detected with a high sensitivity.

To provide a piezoelectric thin film element comprising: a piezoelectric thin film on a substrate, having an alkali-niobium oxide-based perovskite structure expressed by a composition formula (K_1-xNa_x)_yNbO₃, wherein composition ratios x, y of the piezoelectric thin film expressed by (K_1-xNa_x)_yNbO₃ are in a range of 0.4≦x≦0.7 and 0.7≦y≦0.94.

The invention provides a flexible wearable sensor and a corresponding wearable device and preparation method thereof, wherein the flexible wearable sensor is small in size and high in flexible degreeand output capacity. The flexible wearable sensor comprises a first electrode layer, a piezoelectric layer, a second electrode layer, an interval layer, a friction layer and a third electrode layer which are arranged in sequence; a flexible mixed material at least constituted by a piezoelectric material and silicone rubber is contained in the piezoelectric layer, and the piezoelectric layer can generate a piezoelectric signal after being subjected to polarization treatment; a flexible mixed material at least constituted by silicone rubber is contained in the friction layer, a plurality of protrusion parts formed by a plurality of protrusion structures which are configured in an arrayed mode are formed on the opposite areas in the inner surface of the piezoelectric layer and the inner surface of the friction layer correspondingly, and the two inner surfaces are oppositely arranged; the outer surface and the inner surface of the piezoelectric layer are covered with the first electrode layer and the second electrode layer correspondingly; and the interval layer is provided with hollow parts opposite to the protrusion parts on the inner surface of the piezoelectric layer, and the outersurface of the friction layer is covered with the third electrode layer.

The invention discloses a water shooting pressure measurement sensor. The sensor mainly comprises a piezocrystal assembly and an amplifying circuit, wherein the amplifying circuit is arranged in a shell; the piezocrystal assembly is connected with the amplifying circuit through a connecting lead; the amplifying circuit is connected with a signal output cable; the piezocrystal assembly is coated in sound-transparent silicone rubber by an epoxy resin; a graphite layer is coated on the external surface of the sound-transparent silicone rubber; the amplifying circuit is coated by an insulated tape and is packaged in the shell by elastic silicone rubber; one end of the shell is connected with a top cap; the output cable passes through the top cap to be connected with the amplifying circuit; and a screw for fixing the signal output cable is arranged on the shell. The sensor has a simple structure, cannot be easily shot and damaged by explosive products, and can be used for measuring water shooting pressure in a complex environment; and the output cable is reliably connected.

Embodiments of the present invention relates to a piezoelectric element, a manufacturing method thereof, and a piezoelectric sensor. The piezoelectric element comprises a piezoelectric member, a first substrate, a second substrate, a first electrode layer and a second electrode layer, wherein the first substrate and the second substrate are respectively arranged on the two sides of the piezoelectric member. The first electrode layer is arranged between the first substrate and the piezoelectric member, and the second electrode layer is arranged between the second substrate and the piezoelectric member. The surface of the first substrate and/or the surface of the second substrate layer, positioned closer to the piezoelectric member, are/is provided with lug bosses. According to the technical scheme of the invention, the sensitivity of the piezoelectric element is improved.

The invention relates to a single chip silicon SOI high temperature low drift pressure sensor in the field of sensitive sensing technology. Wherein the four voltage-sensitive resistances which form the Wheatstone bridge adopt SOI material; it adopts the interval compensation and the outer compensation technology of partial interval resistance of the SOI resistance network to make the zero point temperature drift below 1X10-6Vs/íµ; it adopts girder-film-island structure to improve the sensibility and linearity of the sensor; it adopts polysilicon with thick boron and the aluminum lead wire covered the lead wire surface to form the interval lead wire of the sensor; it adopts thick boron automatically end technology to make high sensibility high temperature low drift pressure sensor.

The invention belongs to the field of underwater explosion measuring equipment, and particularly relates to a piezoelectric film type sensor used for underwater explosion pressure measurement and a measuring method thereof. According to the sensor, a sandwich type piezoelectric film pressure gage is placed in a hose filled with silicone oil, the two ends of the hose are sealed through plastic plugs, an extension leading wire is led out from a thin through hole of the upper plastic plug, and a flexible fine wire is wound on the outer wall face of the hose. The measuring method includes the steps that (1) the sensor is hung in the same horizontal line with an underwater explosion explosive cylinder through a counter weight, a resistor is connected to the sensor in parallel, a piezoelectric film and the resistor form a powered loop through an extension electrode leading wire, and an oscilloscope is arranged on the loop; (2) after explosives are ignited, voltage signals at the two ends of the resistor are recorded; (3) the quantity of electric charges of the piezoelectric film is obtained through calculation according to the voltage signals, and an explosive shock wave pressure numerical value is acquired through conversion. The piezoelectric film type sensor can be used for directly measuring the pressure change rate of underwater explosion, and is wide in pressure measuring range, convenient to process and low in cost.

The invention relates to a thin film transistor sensor and a fabrication method thereof. The thin film transistor sensor comprises a first substrate and a second substrate, wherein the first substrate and the second substrate are opposite to each other, the first substrate comprises a first flexible substrate and a first grid arranged on the inner side of the first flexible substrate, the second substrate comprises a second flexible substrate and a second grid arranged on the inner side of the second flexible substrate, at least parts of the second grid and the first gird are in opposite, the second grid and the second grid are isolated from each other when the thin film transistor sensor is in a non-working state, an active layer, a source and a drain are further arranged on the first flexible substrate, the active layer is opposite to the first grid, the source and the drain are electrically connected with the active layer. In the thin film transistor sensor, spatial point contact changes of the first grid and the second grid of a flexible thin film transistor are utilized to realize the switching function of the thin film transistor, and thus, the effect of the sensor is achieved.

The invention relates to a surface acoustic wave pressure sensor adopting a compound die, which pertains to the technical field of sensors and comprises a mushroom pressurization cap, a hard-core ball shell pressure guiding metal diaphragm, a metal force guiding column, an overvoltage protective device, a metal shell side wall, a force guiding ejector disk, a force guiding cylinder, a quartz cantilever beam sensitive element, a bottom case and an overvoltage protective device, wherein, the hard-core ball shell pressure guiding metal diaphragm, the metal shell side wall and the bottom case form an air-tight container; the upper surface of the hard-core ball shell pressure guiding metal diaphragm is connected with the mushroom pressurization cap by the metal force guiding column, while the lower surface thereof is fixed with the force guiding ejector disk rigidly connected with the force guiding cylinder; the interior of the force guiding cylinder is provided with the quartz cantilever beam sensitive element; one end of the quartz cantilever beam sensitive element is connected with a blind hole end surface of the force guiding cylinder by glass powder, while the other end thereof is connected with a blind hole of the metal shell side wall by utilizing glass powder. The flexibility of the invention is 15 times higher than the conventional surface wave sensor, and the surface acoustic wave pressure sensor of the invention is suitable for the wireless monitoring of the tire pressure of carts.

The invention provides a pressor sensor for reducing error of pressure measurements. The pressure sensor includes: a housing; a pressure receiver which seals an opening of the housing and transmits pressure from outside the housing to the inside of the housing; and a pressure sensing element having a pressure sensing portion and a pair of base portions which are respectively coupled to both ends of the pressure sensing portion. In the pressure sensor, a force detecting direction is set to be a detection axis, a line connecting the pair of base portions and a displacement direction of the pressure receiver are arranged in parallel, one of the base portions is coupled to a central region, which is displaced by the pressure, of the pressure receiver, and the other of the base portions is coupled to a marginal region, which is at a fixing side, of the pressure receiver through a connecting member.

An object of the present invention is to provide a charge amplifier which can be operated at low cost so that electric charge generated in a piezoelectric pressure sensor having one end grounded is converted into a voltage signal.

In the charge amplifier (1) according to an embodiment of the present invention, a plus side power source input terminal of an operational amplifier (5) is connected to a plus power source (+5 V) while a minus side power source input terminal of the operational amplifier (5) is grounded, so that the operational amplifier (5) is supplied with a single power source. Further, an offset voltage lower than the plus power source voltage but higher than the ground potential is applied to a non-inverted input terminal of the operational amplifier (5). Accordingly, change of pressure in both positive and negative directions can be converted into a voltage signal with the offset voltage as its center though the operational amplifier (5) is driven by a single power source. That is, cost can be suppressed because a double power source is not required.

A liquid container includes; a liquid containing portion for containing liquid therein; a unit case, including a liquid inlet communicating with the liquid containing portion, a liquid outlet for supplying the liquid outside, a flexible diaphragm that covers an upper opening of the unit case and that is displaceable depending on liquid pressure between the liquid inlet and the liquid outlet; a movable member attached to the flexible diaphragm and that has a pair of shafts formed to protrude from opposite sides of the movable member: a sensor assembly attached to a bottom opening formed in a bottom plate of the unit case and used for detecting that the liquid in the liquid containing portion is exhausted to a predetermined amount; and a pair of shaft receiving portions that is provided on the unit case for receiving the pair of the shafts to fix the movable member in a predetermined position in an initial state where the liquid has not flowed from the liquid inlet to the detection portion.

A quartz girder resonant mode micro-pressure sensor chip with a silicon substrate single island structure comprises a quartz girder which is bonded on the front of the silicon substrate through low stress adhesive glue. Four opposite angles of the quartz girder are directed at four alignment markers on the front of the silicon substrate. The back of the silicon substrate is connected with a glass substrate in a sealing mode. The front of the glass substrate corrodes a groove. A pressure hole is formed at the center of the groove. The pressure hole is communicated with the atmosphere to form a gauge pressure sensor, or is communicated with the other tested atmosphere to form a differential pressure type sensor. The back of the silicon substrate corrodes the groove to form a silicon island. The quartz girder is driven to self-oscillate with an inverse piezoelectric effect of the quartz and when vibration frequency is equal to the inherent frequency of the quartz girder, resonance oscillation occurs. Resonant frequency is tested under a closed-loop feedback control system. Variable quantity of the resonant frequency represents the size of air pressure to be tested, and therefore the measurement of the outside air to be measured can be realized. The quartz girder resonant mode micro-pressure sensor chip with the silicon substrate single island structure has the advantages of being high in sensitivity, high in accuracy and high in resolution ratio.