57results about How to "Increased strain sensitivity" patented technology

A telemetric tibial tray includes a lower plate that defines a plurality of cylindrical transducer cavities having circular load diaphragms. An upper plate is attached to the lower plate through support posts projecting from the load diaphragms. The support posts have a circular cross-section and a diameter of about 5.0 mm. The lower plate further defines wiring channels communicating between the transducer cavities and a central cavity housing the circuit board for the telemetric tray. The wiring channels are arranged at a 45 degree angle relative to the sagittal plane of the knee joint in order to reduce the effects of the wiring channel intersection on the strain sensitivity of the tray. Each transducer cavity includes a radial strain gage array with four pairs of radially aligned strain gages, each pair aligned at a 45 degree angle relative to the sagittal plane of the knee joint. Each pair of strain gages includes an inner gage positioned at the point of maximum positive micro-strain across the diaphragm when loaded, and an outer gage positioned at the point of maximum negative micro-strain, to thereby increase the differential strain measured by the gages and increase the strain sensitivity of the tibial tray.

The present invention relates to a system for sensing the curvature of a towed hydrophone array and a curvature sensor used in the system. The system has at least two curvature sensors positioned along the length of the array. Each of the curvature sensors comprises a bend member which bends as the array bends, at least one optical fiber within the bend member, and at least one detection device embedded within the at least one optical fiber to detect a change in the strain in the at least one optical fiber.

A threaded member capable of detecting tightening force includes a head section, a threaded rod section and at least one strain sensor. The head section has a bottom face, a skirt section and a receiving space. The threaded rod section is disposed under the bottom face of the head section. A sink section is formed on the bottom face of the head section. The strain sensor is disposed on the bottom face of the head section and positioned in the receiving space. Due to the sink section, when the head section is strained and deformed, the strain sensor can sensitively and precisely detect the strain capacity of the head section and provide the tightening force of the threaded member for a user to more precisely tighten the threaded member.

The invention discloses a metal-encapsulated fiber Bragg grating sensor and a manufacturing method thereof. By encapsulating the fiber Bragg grating in a steel pipe through a specific manufacturing method, the sensor of the invention improves the strain sensitivity compared with the prior art, and Easy to install.

The invention relates to a method for preparing a film strain sensor. The method comprises steps that a film insulating layer is prepared on a metal substrate. A metal sensitive film layer is formed on one side of the film insulating layer. A first bonding layer is formed on a side of the metal sensitive film layer away from the film insulating layer. A graphene layer is formed on a side of the first bonding layer away from the metal sensitive film layer. A second bonding layer is formed on a side of the graphene layer away from the first bonding layer. The metal sensitive film layer, the first bonding layer, the graphene layer and the second bonding layer have the same shape and are stacked in order to form a resistance grid and an electrode connection structure. The method is advantagedin that the film strain sensor can have the characteristics of both metal and graphene, so the film strain sensor has both excellent electrical conductivity and strong physical property, has advantages of high sensitivity and a wide range of installation environments and can be used in harsh environments such as acid and alkali, salt spray, and high and low temperature alternation.

The invention discloses an aramid nanofiber/polyvinyl alcohol/polyaniline composite hydrogel, and a preparation method and application thereof. The composite hydrogel is prepared with aramid nanofibers and a polyvinyl alcohol hydrogel as matrixes and through in-situ polymerization with polyaniline under an acidic condition. Under the interaction of various hydrogen bonds, the mechanical strength and toughness of the composite hydrogel are remarkably improved. Meanwhile, due to the existence of the conductive polyaniline, the composite hydrogel disclosed by the invention has relatively high sensitivity, and can repeatedly and stably detect the changes of electric signals in practical application. The composite hydrogel provided by the invention has high mechanical strength, high toughness and high sensitivity, and is applicable to the field of wearable strain sensors.

A bolus, for introduction into a ruminant animal's reticulum to register pressure signals transmitted through fluids therein, has a case unit adapted for immersion in the fluids. A mechanical amplifier element extends out from the case unit and is adapted to be surrounded by the fluids in the reticulum and absorb mechanical energy from the pressure signals. A guide part conveys mechanical energy from the mechanical amplifier element to a sensor module in the interior of the case unit. The sensor module transduces the pressure signals into electric signals from which a processing module extracts data representing body movements, a heart beat rate, a respiratory rate, a respiratory depth and/or stomach activity of the animal. A communication module in the case unit receives the data and transmits output radio signals reflecting the data.

The invention discloses a strain sensor based on an optical fiber Fabry-Perot cavity and a manufacturing method thereof, which belong to the technical field of optical fiber sensors. The sensor comprises a first optical fiber with a first end surface and a second optical fiber with a second end surface; the first end surface and the second end surface are in butt joint to form the Fabry-Perot cavity; and the Fabry-Perot cavity is internally provided with an air gap. According to the sensor with the microcavity structure in the design, the strain measurement sensitivity of the optical fiber strain sensor is greatly improved, and the temperature strain cross sensitivity is extremely low.

A manufacturing method for a high-temperature-resistant metal-packaged fiber Bragg grating sensor includes using a regenerated fiber Bragg grating obtained via high-temperature annealing as a sensitive element so that the grating will not be erased when used at high temperature. The method also includes using a magnetron sputtering method which makes an optical fiber and metal combine better to form on the surface of the optical fiber an adhesive layer and a conductive layer, thereby causing little damage to optical fiber because of the absence of the processes of coarsening, sensitization, etc. of electroless plating and the fact that the method is performed in an anhydrous environment. After magnetron sputtering, the method includes using an electroplating method to thicken and deposit a protective layer, and embedding the optical fiber in a flexible-structure metallic substrate through the electroplating method to achieve the all-metal package.

The invention relates to a sensitivity enhancement demodulation method and device of a fiber optical Bragg grating strain sensor and belongs to the technical field of optical detection devices. The method comprises the following steps: outputting original laser which is as the same as resonant wavelength of FBG (Fiber Bragg Grating) and changes synchronously in real time by an optical fiber laser as pump light; after combining the pump light and signal laser at another wavelength, carrying out chirped amplification of frequency in a non-linear system to realize high order four-wave mixing; and finally, realizing high sensitivity detection of wavelength drift and corresponding strain of the original laser through wavelength analysis of idle light. According to the invention, sensor demodulation with high strain sensitivity can be obtained at wavelength near 1550nm, and high strain sensitivity which is higher than intrinsic sensitivity of FBG can be obtained in the demodulating process based on common FBG, so that the method and device provided by the invention are suitable for sense application of high strain sensitivity.

Provided modified aluminate cement is prepared from the following raw materials: aluminate cement, titanium-silicon micro-nano capsules, magnesium oxide, a phosphate, fly ash, modified acrylic emulsion and an activating agent, wherein the titanium-silicon micro-nano capsule is prepared from orthosilicate and titanate under the conditions of a surfactant and alkalinity. The aluminate cement prepared by the invention is wide in raw material source and simple in preparation method, has good high-temperature resistance, wear resistance, sulfate corrosion resistance, adhesion, crack resistance, freezing resistance, seepage resistance, corrosion resistance and aging resistance, also has good effects of adsorbing and degrading formaldehyde and organic pollutants due to the TiO2 structure, plays agood role in environmental protection, ensures the safety as a structural part, and has a wide application prospect.

The invention discloses a wireless passive detection system for the tension of a high-voltage transmission line, and the system comprises a tension sensor, a clamping and tension transmission mechanism, and a wireless reader. The tension sensor is installed at a to-be-detected part of the high-voltage transmission line through the clamping and tension transmission mechanism, and is in signal transmission connection with the wireless reader. According to the invention, the system employs a surface transverse wave strain sensitivity theoretical model, integrates the strain sensitivity and a frequency temperature coefficient, and is provided with the dedicated clamping and tension transmission mechanism for measuring the tension of the high-voltage transmission line, wherein the clamping and tension transmission mechanism can be conveniently installed at any detected point on the transmission line, and can prevent the bending moment and torque from affecting the measurement of tension. The wireless reader is used for remotely querying the frequency shift of an STW resonator installed on the transmission line, i.e., obtaining the tension value of a detected point. The wireless reader can be installed on a mobile platform, and can achieve the routing inspection of a surface transverse wave tension sensor at a place which is 10m far.

The invention discloses a crack flexible strain sensor based on a graphene-gold composite film and a preparation method thereof. The preparation method comprises the following steps of preparing a metal electrode on a PDMS flexible substrate through a mask method, forming a quasi-continuous graphene film by using a liquid level self-assembly method, transferring the graphene film to a flexible substrate covering the sensing unit mask through a pulling method, performing magnetron sputtering of nanogold on the surface of the graphene to prepare a graphene-gold composite film, and pre-stretching the PDMS flexible substrate to enable the graphene-gold composite film to generate an initial crack, thereby obtaining the flexible strain sensor based on the graphene-gold composite film crack. The process conditions are mild, array batch manufacturing is easy, the prepared sensor has high sensitivity and a large linear range, the sensitivity can be improved through a mask patterning method, and the sensor is suitable for being integrated in a sensing system to complete strain measurement in a wide range.

The invention discloses a cellulose-dopamine/carbon nano tube based conductive fiber and a preparation method and application thereof. Through a wet spinning method, dopamine (DA)-modified carboxymethylcellulose (CMC) is used as a fiber framerwork, a carbon nano tube (CNT) is used as conductive filler, and the cellulose-dopamine/carbon nano tube based conductive fiber is prepared and is furthermore prepared into a flexible sensor. The flexible sensor formed by assembling the conductive fiber has the characteristics of high flexibility, high mechanical property, high conductivity and strain sensitivity and is expected to serve as new wearable electronic equipment to serve for future robots, artificial limb users and human body real-time motion detection equipment. According to the cellulose-dopamine/carbon nano tube based conductive fiber, the raw material source is rich, the cost is low, the preparation process is simple, the implantation performance is high, and the cellulose-dopamine/carbon nano tube based conductive fiber has huge potential in application to the fields of wearable electronic devices, flexible energy devices and the like.

The invention discloses a high-temperature-resistant optical fiber strain sensor. The left end of a hollow-core optical fiber is welded with a first single-mode optical fiber, and the right end of thehollow-core optical fiber is bonded with a second single-mode optical fiber positioned in a capillary glass tube by using high-temperature ceramic glue; a high-temperature ceramic adhesive layer is formed after the high-temperature ceramic glue is solidified, a Fabry-Perot interference cavity is formed by the splicing surface of the first single-mode optical fiber and the hollow-core optical fiber and the splicing surfaces of the hollow-core optical fiber, the hollow-core optical fiber and the second single-mode optical fiber, and a thermal regeneration Bragg grating is inscribed on the second single-mode optical fiber. According to the invention, the problem of temperature and strain double-parameter cross sensitivity is effectively solved. Compared with a traditional optical fiber strain sensor, the strain sensitivity of the strain sensor is improved, the strain detection range is 0-700 [mu][epsilon], the temperature detection range is room temperature to 1000 DEG C, the strain detection range and the temperature detection range are expanded, and the optical fiber strain sensor has the advantages of the simple structure, the small size, high sensitivity and the like, and can beused as a strain sensor.

The invention provides an impact force detection mechanism based on Galfenol alloy. The impact force detection mechanism comprises a base, a detachable module arranged on the base and a Galfenol beam connected to the base through a thread. The Galfenol beam is the main body of the detection mechanism. The tail part of the Galfenol beam is closely attached to a permanent magnet. A signal extraction coil is arranged in the middle part of the Galfenol beam. The end part of the Galfenol beam is closely connected with a force transmission rod. A force applying module is connected to the force transmission rod. A limiting boss arranged on the base is arranged at the bottom of the force transmission rod. The exterior of the permanent magnet is wrapped in a damping layer. The permanent magnet is arranged in a cavity between the base and the detachable module. The detection mechanism is simple in structure, easy to install and capable of achieving measurement impact load. In addition, the Galfenol beam as the detection main body is of a cantilever structure, so flexibility of the detection mechanism can be effectively improved.

The invention discloses an electric heating wire based on cellulose-dopamine/carbon nanotube conductive fibers and the application of the electric heating wire. A wet spinning method is used, dopamine(DA) modified carboxymethyl cellulose (CMC) is used as a fiber framework, carbon nanotubes (CNT) are used as a conductive filler to prepare DACMC/CNT-based conductive fibers, and the DACMC/CNT-basedconductive fibers are further woven into electric heating wires. The electric heating wire woven by the conductive fibers has the characteristics of high strain sensitivity, high temperature rise speed and high moisture resistance, and is expected to be applied to wearable electronic equipment as a weaving material to serve a health-care electric heating device, a heating textile, human health monitoring and a human-computer interaction interface. The electric heating wire is rich in raw material source, low in cost, simple in preparation process and high in practicability, and has huge potential in the application in the fields of soft robot technologies, flexible energy devices and the like.

Methods for measuring and/or mapping in-plane strain of a surface of a substrate. A grating is formed on at least a portion of the surface of the substrate. A laser is then used focused onto the grating to determine the strain on the surface by determining the variation of the grating wavelength due to the strain on the surface. The strain information is essentially carried by the grating, in terms of grating wavelength, because it varies according to the volume change of the underlying substrates. By scanning the surface grating with the small laser size, a high resolution strain map of the surface can be produced. The induced strain is related to the grating wavelength variation, which leads to the diffraction angle variation that is captured by the strain sensing measurements.

The invention relates to the axial strain measuring system based on a double-refraction optical loop mirror. The axial strain measuring system comprises an optical fiber coupler, a double-refraction optical fiber, a light source and a spectrograph. The two ends of the double-refraction optical fiber are connected with two output arms of the optical fiber coupler respectively, the light source is connected with a light source input port of the optical fiber coupler, and the input end of the spectrograph is connected with an interference spectrum output port of the optical fiber coupler. The birefringence of the double-refraction optical fiber is 7.7024*10-6-2*10-4. According to the axial strain measuring system based on the double-refraction optical loop mirror, the double-refraction optical fiber with the birefringence of 7.7024*10-6-2*10-4 is applied, the cost is controlled, the system complexity is not increased, the strain sensitivity of the double-refraction optical loop mirror can be effectively improved, and the axial strain measuring system has high application value.

The invention provides a method for measuring strain by the aid of fiber F-P (Fabry-Perot) sensors. The method includes manufacturing the fiber F-P sensors, fixing fiber fixtures onto high-precision three-dimensional movement platforms and fixing HI-1060 fibers without coatings onto the fiber fixtures; sequentially transmitting femtosecond laser through half-wave plates, polarizers, attenuation slices and windows, reflecting the femtosecond laser via high-reflectivity mirrors, then focusing the femtosecond laser on the HI-1060 fibers and carrying out scribing and writing on the HI-1060 fibers;arranging charge coupled devices right above the high-reflectivity mirrors and observing focusing locations of the laser and morphology of the HI-1060 fibers on the fixtures; constructing strain testsystems comprising broadband light sources, circulators, the fiber F-P sensors, movable stretching platforms and spectrum analyzers; fixing the fiber F-P sensors onto the movable stretching platformsand allowing the fiber F-P sensors to generate the strain; observing and recording reflection spectra of the fiber F-P sensors by the aid of the spectrum analyzers in real time. The HI-1060 fibers with the observed morphology are processed by the laser. The method has the advantage that the fiber F-P sensors manufactured by the aid of the method are high in strain measuring sensitivity.

The present disclosure discloses a strain sensor and a method of fabricating the same. The strain sensor according to an embodiment of the present disclosure includes an X-axis sensor formed on a flexible insulating substrate and responsible for sensing X-axis strain; a Y-axis sensor formed on the flexible insulating substrate to be orthogonal to the X-axis sensor and responsible for sensing Y-axis strain; a metal electrode formed on a region of the flexible insulating substrate where the X-axis sensor and the Y-axis sensor are not formed; and an encapsulation layer formed on the X-axis sensor, the Y-axis sensor, and the metal electrode. In this case, the X-axis sensor and the Y-axis sensor have a metal-insulator heterostructure.

The invention discloses a light intensity modulation type signal demodulation system and signal demodulation method, and belongs to the technical field of light intensity modulation. A high-performance function signal generator is applied to provide an excitation source to light modulation signals, the light modulation signals enter a sensing optical fiber and a reference arm optical fiber through an optical fiber coupler, and reflected light carries strain and temperature information to reach a photoelectric detector through a coupler. The signals are accessed to an oscilloscope through amplification and filtering processing so as to observe phase difference. The system is simple in structural arrangement, high in sensitivity, high in precision and rapid in reaction. The method can be used for various occasions requiring obtaining of real-time strain monitoring data.