38results about How to "Significant change in resistance" patented technology

The invention provides a flexible piezoresistive touch sensor array and a preparation method thereof. The sensor array comprises N*N separated piezoresistive layers and a coplanar electrode layer. The piezoresistive layers are arranged on the coplanar electrode layer. Each piezoresistive layer comprises an upper finger pressing layer, a middle sensitive layer and a bottom sensitive layer, wherein the three layers are each provided with a micro pyramid; the coplanar electrode layer comprises a polymer electrode substrate and N*N gold electrode pairs located on the polymer electrode substrate. The piezoresistive layers adopt polymer films with the micro pyramid, and due to the three-layer structure, the sensitivity of the sensor at the low-voltage region can be greatly improved. In addition, in order to overcome the defect that a traditional touch sensor is large in crosstalk due to a sandwiched structure, the coplanar electrode layer is adopted, all electrodes are located on the same plane, each piezoresistive layer is attached to the corresponding electrode pair, the piezoresistive units are completely separated, and the sensitivity and anti-interference capacity of the sensor are effectively improved.

The invention discloses a conductive hydrogel composite material which is sensitive to humidity level fluctuation, a device and a preparation method, which relates to a smart material and a device and a preparation method, wherein, the conductive hydrogel composite material and the preparation method thereof comprises four steps of dispersion of conductive filling materials, in situ polymerization, casting to be shaped and electrode trimming; the conductive hydrogel composite material and the device comprise a hydrogel which is sensitive to humidity level fluctuation, the conductive filling materials and an additive. In the process of responding to the environmental moisture change, the obtained conductive hydrogel composite material and the device can make a sensitive response to the external moisture change. The conductive hydrogel composite material and the device can obtain practical applications in the fields of biomedicine, fluid control, diffusion and permeation, intelligent machinery and the like.

A first and a second tunnel junctions (2 and 3) which have a common electrode composed of a nonmagnetic conductor (4) and each of which has a counterelectrode composed of a ferromagnet (6, 8) are disposed spaced apart from each other by a distance that is shorter than a spin diffusion length of the nonmagnetic conductor (4) wherein the first tunnel junction (2) acts to inject spins from the ferromagnet (6) into the nonmagnetic conductor (4) and the second tunnel junction (3) serves to detect, between the ferromagnetic metal (8) and the nonmagnetic conductor (4), a voltage that accompanies spin injection of the first tunnel junction (2) and wherein the nonmagnetic conductor (4) is a nonmagnetic conductor, such as a semiconductor or a semimetal, that is lower in carrier density than a metal. The common electrode alternatively may be composed of a superconductor (4′). A spin injection device thus provided can exhibit a large signal voltage with low current and under low magnetic field and can be miniaturized in device size. Magnetic apparatuses utilizing such a spin injection device are also provided.

The invention provides a flexible pulse sensor and a manufacturing method thereof. The flexible pulse sensor comprises a flexible base, carbon nano tube-graphene composite film of which part is embedded into the flexible base, and electrodes, wherein the electrodes are arranged at two ends of the carbon nano tube-graphene composite film; the thickness of the flexible base is 0.8-1.2mm; the light transmittance of the initial carbon nano tube is 85-95%, and the light transmittance of the carbon nano tube-graphene composite film obtained through chemical vapor deposition is 80-92%. According to the flexible pulse sensor and the manufacturing method thereof, the carbon nano tube, the graphene and the flexible base synergize with one another so that the flexible pulse sensor can not only have the advantages of the graphene and the carbon nano tube sensor but also avoid the disadvantages of the graphene and the carbon nano tube sensor, the mechanical stability of a strain sensor is strengthened, the pulse sensor does not lose efficacy within at least 10% of strain ranges, the pulse sensor can effectively catch pulse signals, and the detecting effect is reached.

The invention discloses a synaptic transistor based on a two-dimensional semiconductor material and a preparation method of the synaptic transistor. The synaptic transistor comprises an insulating substrate, and a channel, a source electrode, a drain electrode and a gate electrode which are arranged on the substrate, wherein the channel is a two-dimensional semiconductor material; the source electrode and the drain electrode are arranged at the two ends of the channel respectively and form an ohmic contact with the channel material; the gate electrode and an electrical interconnection system formed by the channel, the source electrode and the drain electrode are kept in electronic insulation; an organic electrolyte covers a channel region and most of the gate electrode and comprises an organic carrier capable of being electrically insulated and ions capable of being migrated, and effective ion control of the gate to the channel material is formed. According to the synaptic transistor based on the two-dimensional semiconductor material and the preparation method of the synaptic transistor, an ion attachment-intercalation mechanism is utilized, and the characteristics of large surface area and adjustable resistance value of the two-dimensional material are combined, so that the device shows long-term and short-term synaptic plasticity, and the two characteristics can change witheach other along with the change of a gate signal. Meanwhile, the device has good linearity and ultralow operational power consumption, and the implementation and large-scale integration application of a high-precision neuromorphic device are facilitated.

A shear strain type pressure sensor comprises a shell. A magnetic field generating device in the shell comprises two magnetic poles which are opposite in magnetism and correspond to each other oppositely. A shear plate is arranged in the gap between the two magnetic poles, a rubber sheet is fixed on one side of the shear plate and in full contact with the end face of the first magnetic pole in the two magnetic poles, and a first electrode is fixed on the other side of the shear plate and fixedly provided with a magnetorheological elastomer. A second electrode is fixed on the other side of the magnetorheological elastomer, the second electrode is fixedly connected with the end face of the second magnetic pole in the two magnetic poles, the first electrode and the second electrode are electrically connected with a signal conditioning module, one end of the shear plate upwards extends to penetrate through an S-shaped force measuring piece and then extends out of the upper end face of the shell, a supporting plate used for supporting the S-shaped force measuring piece is fixed in the shell, a stop piece is arranged on the shear plate, and the lower end face of the stop piece is in contact with the upper end face of the S-shaped force measuring piece. The shear strain type pressure sensor is high in resolution, high in sensitivity, and large in force testing range.

The invention relates to a color-variable flexible electronic skin and a preparation method thereof. The preparation method comprises the steps of: (1) preparing a PDMS substrate; (2) preparing a salient point microstructure PDMS; (3) preparing a conductive graphite type thin film salient point microstructure PDMS substrate; (4) preparing a TCO/PDMS counter electrode substrate; (5) placing the TCO/PDMS counter electrode substrate on the conductive graphite type thin film salient point microstructure PDMS substrate to form a resistive pressure sensor; (6) preparing solid/colloidal electrolyte;(7) preparing a flexible ECD; and (8) integrating a flexible ECD with the resistive pressure sensor to form a power amplifier circuit. The color-variable flexible electronic skin is a chameleon simulating color-variable skin, has relatively good performance to pass color variation, and is capable of feeling external temperature and surrounding environment change and giving alarm or prompt. The preparation method is simple, efficient and low in cost, is capable of realizing reel-to-reel industrial production and can be used for monitoring, for environment, of natural people, artificial intelligence and robots.

The invention relates to a high sensitivity flexible pressure sensor and a preparation method thereof; the sensor comprises a conductive silica gel layer and a flexible substrate arranged below the conductive silica gel layer; the flexible substrate is a silica gel layer and in a hollow structure, and arranged in a shape of a Chinese character chuan or jing, or in a rhombus hollow structure; a bonding layer is arranged below the flexible substrate, and made of a hot melt adhesive. The flexible substrate of the flexible pressure sensor is in a hollow structure; the conductive silica gel layer can form bigger deformations when receiving external pressures, and the resistance change is more obvious, so the sensor is more sensitive; different hollow structures can bring about different sensitivities and piezoelectric relations; the hollow structure can be changed so as to adapt to pressure sensors of different occasions; the hot melt adhesive bonding layer can firmly glue the flexible pressure sensor on clothes through hot pressing; the flexible pressure sensor is wearable, hard to drop, and durable.

The invention discloses a method for measuring the piezoresistive coefficient of a double-end fixed-supported beam based on SOI silicon wafers, which includes the following steps: through force analysis, it is obtained that under the action of an electrostatic force uniform load, the upper part of the double-ended fixed-supported beam is located at The size of the compressed area in the middle position is the length of the double-end fixed beam, and it is doped within this range; the two ends of the doped area are heavily doped; in the heavily doped area, the corresponding anchor Metal aluminum is deposited in the region and the region between the heavily doped region and the anchor region; multiple metal wires are connected on the anchor region; a semiconductor parameter tester capable of measuring resistance is connected between the metal wires in the two anchor regions; An external voltage source that can apply an electrostatic bias voltage is added between the metal wire in the anchor area and the electrode of the substrate; the piezoresistive coefficient of the double-terminal anchored beam is measured and calculated. The invention avoids the canceling effect of the tension region and the compression region in the double-end fixed support beam, and has accurate measurement results and simple and convenient measurement method.

The invention discloses a novel perovskite manganese-based oxide thin film material. The perovskite manganese-based oxide thin film material has the general chemical formula of La<0.67>(Ca<x>Ba<1-x>)<0.33>MnO<3>, wherein Mn is metal manganese and O is oxygen; and the perovskite manganese-based oxide thin film material has an ABO<3> type perovskite crystal structure. The perovskite manganese-based oxide thin film material is obvious in resistance change under an external magnetic filed and relatively high in magnetic resistance; the metal-insulation transformation temperature and magnetic resistance maximum value can be continuously adjustable along with content changes within a temperature range of 230-270K; and in addition, the thin film material has high magneto-electricity performance.

The invention discloses ionic conductive hydrogel as well as a preparation method and application thereof. The preparation method comprises the following steps: step 1, preparing a phenylboronic acid ionic liquid monomer; and 2, preparing the ionic conductive hydrogel according to the product obtained in the step 1. The multifunctional ionic conductive hydrogel provided by the invention is applied to a sensor and is prepared from the multifunctional ionic conductive hydrogel, and the two ends of the multifunctional ionic conductive hydrogel are connected with wires and packaged. The sensor comprises but is not limited to a man-machine interaction sensor, electronic skin and the like. The electronic skin is also called as a novel wearable flexible bionic tactile sensor.

The invention provides a three-dimensional flexible sensor material as well as a preparation method and application thereof, and the preparation method of the sensor material comprises the following steps: adding a conductive agent, a binder and a reinforcing agent into water, and uniformly dispersing to obtain printing ink; the printing ink is made into a device in a 3D printing mode, and then the device is soaked in a cross-linking agent solution; and drying the device containing the cross-linking agent in a freeze-drying manner to obtain the cross-linking agent. The flexible sensor can effectively solve the problems that an existing sensor is large in hardness and poor in fitting degree.