78 results about "Electrocaloric effect" patented technology

A wiring substrate with improved heat dissipation capability and with reduced size is disclosed. The wiring substrate includes a metal core substrate, a buffer layer formed so as to cover at least a part of the metal core substrate and containing a phase change material or a material with an electrocaloric effect, an electronic device mounted on a surface of a base including the metal core substrate and the buffer layer or inside the base, and a thermal via formed between the electronic device and the buffer layer.

The invention provides a barium-titanate-based colossal-electrocaloric-effect chip-type laminate ceramic electrocaloric refrigeration device. The chip-type laminate ceramic employs perovskite ABO3 structural barium titanate as a matrix for A-position doping or B-position doping or A position and B position simultaneous doping, so that a combined phase is formed. The device possesses the following advantages that through doping, the sintering condition of the chip-type laminate ceramic is improved, the sintering temperature is reduced and further energy consumption of the technology is reduced; the material mechanical properties (pressure resistance, stretching performance, shearing performance and toughness) are improved, and the material can satisfy demands of more usage environments; and the effective working temperature interval of the material is expanded.

The invention belongs to the field of functional fibers and particularly relates to an electrochromic fiber and a preparation method and application thereof. The electrochromic fiber comprises a composite material in a three-layer structure which comprises a coating layer, a middle layer and a core layer sequentially from outside to inside, wherein the coating layer is a protective layer, the middle layer is an electrochromic layer, and the core layer is a conductive layer. The conductive layer is made of a conductive layer material with an electrothermal effect; the electrochromic layer is prepared according to a thermal softening wire-drawing method, and a preformed rod of the electrochromic layer comprises a hole structure; the conductive layer material penetrates a hole of the preformed rod, and the conductive layer serving as the core layer is prepared in the electrochromic layer while the electrochromic layer is obtained according to the thermal softening wire-drawing method. Inuse of the electrochromic fiber, the conductive layer material emits heat under an electrified condition, and the electrochromic layer material of the middle layer gives play to a color changing function under the thermal action of the conductive layer.

A cooling device utilizing the polymer composite materials possessing high electrocaloric effect and high elastic modulus are disclosed. Especially methods to enhance mechanical properties and reduce creep of the polymer composites with insulation fibers of high elastic modulus while maintain high electrocaloric effect.

The invention discloses a self-destruct nonvolatile memory chip and a preparation method thereof. The self-destruct nonvolatile memory chip comprises a memory chip and a self-destruct function layer formed thereon, wherein the self-destruct function layer sequentially comprises an insulating layer, a heating layer, a passivation layer and bonding pad metal from the bottom up. According to the invention, the heating layer is adopted to be connected with an external self-destruct circuit, the self-destruct circuit sends pulse ignition signals to the heating layer when judging that self-destruction is required to be carried out, the heating layer generates an electric heat effect, the temperature rises instantaneously, the memory chip located below the heating layer is heated, a tolerable temperature of the internal structure of the memory chip is exceeded, so that the memory chip is physically destructed, the memory chip is enabled to have irreversible structural and functional damages, and physical hardware self-destruction of information in the memory chip is realized. Compared with an existing memory chip, the self-destruct nonvolatile memory chip disclosed by the invention has the advantages of small memory chip change, high output, simple process, low cost and the like. The self-destruct nonvolatile memory chip has a flexible structure and extensive applicability.

A solid-state heat transporting device including a heat transporting element whose uniformity of contact with one or multiple surfaces is controllable so that various amounts of heat may be transported to and from the one or multiple surfaces. The heat transporting element uses the electrocaloric effect to absorb and release the heat and the uniformity of contact is controlled using an electrostatic effect which may change the shape of the heat transporting element. In one embodiment, the heat transporting element is an electrostatically actuated P(VDF-TrFE-CFE) polymer stack achieving a high specific cooling power of 2.8 W/g and a COP of 13 (the highest reported coefficient of performance to date) when used as a cooling device.

The invention relates to the technical field of ferroelectric film preparation, in particular to a preparation method of a film for regulating and controlling electrocaloric performance through a substrate, and belongs to the technical field of chemical engineering. The method comprises the following steps: spin-coating a LaNiO3 precursor solution on the substrate to prepare a first wet film, andperforming drying, pyrolyzing and annealing to prepare a layer of LaNiO3 film; repeating the previous steps to prepare a composite substrate with multiple layers of LaNiO3/substrates; spin-coating thePb0.78Ba0.2La0.02ZrO3 precursor solution on a composite substrate to prepare a second wet film, and performing drying, pyrolyzing and annealing the second wet film to prepare a layer of Pb0.78Ba0.2La0.02ZrO3 film; and repeating the previous steps to prepare the multi-layer Pb0.78Ba0.2La0.02ZrO3 thin film. The invention further discloses a preparation method of the Pb0.78Ba0.2La0.02ZrO3 thin film.According to the method, the film with the advantages of high purity, good compactness, small average grain size, high electric field breakdown strength, high electrocaloric effect and the like can be obtained.

The invention discloses an all-solid-state electrocaloric refrigerator. A third electrode layer serves as a center layer. An electrocaloric refrigeration unit cold end formed by sequentially attaching a second electrocaloric material layer and a second electrode layer to one side is connected with a refrigeration sheet. An electrocaloric refrigeration unit heat end formed by sequentially attaching a first electrocaloric material layer and a first electrode layer to the other side is connected with a cooling sheet. The all-solid-state electrocaloric refrigerator further comprises a first power source and a second power source, wherein the first power source is connected with the cold end so as to provide pulse voltages, and the second power source is connected with the heat end so as to provide pulse voltages. The electrocaloric material layers are made of ferroelectric materials or relaxor ferroelectric materials with an electrocaloric effect. Film materials with excellent heat conduction but without electric conduction are sputtered on the surfaces of the first electrode layer and the third electrode layer which make contact with the refrigeration sheet and the cooling sheet, and the film materials can be BeO or AlN.

The invention relates to an electrocaloric effect refrigeration composite thick film material. The composite thick film material comprises a SrTiO3 buffer layer and a (Pb1-3z/2Laz)(Zr1-x-ySnxTiy)O3 anti-ferroelectric thick film layer, wherein 0<=x<=0.45, 0<=y<=0.10, 0<=z<=0.06, and the SrTiO3 buffer layer is located between a substrate and the (Pb1-3z/2Laz)(Zr1-x-ySnxTiy)O3 anti-ferroelectric thick film layer. The composite thick film material has a high dielectric constant and high refrigeration efficiency and energy conversion efficiency and is suitable for development of micro-refrigerators with high refrigeration efficiency and energy conversion efficiency.

Currents act on metal, and an electric heating effect and electrically induced plasticity are achieved, wherein a high-frequency pulse current effect has the capacity of healing metal plastic strain damage. Electrically induced plasticity and electric heating softening effects are introduced into the precision blanking technology, and the precision blanking difficulty of high-strength steel platesis reduced. Metal materials are heated to expand through the electric heating effect, the defect that in the blanking medium-terminal stage, hydrostatic pressure stress of shear zones of the metal materials is reduced rapidly is relieved, and the capacity of restraining production-extension of holes of the shear zones is improved. By means of a good-time and proper pulse current acting manner anda loading method, current energy is intensively injected in good time at high density aiming at local zones, where the holes and micro-cracks are easily generated in the blanking process, of the shear zones, strain damage is repaired, the situation that the micro-cracks are further developed into macro-cracks, and a rough tear zone on a precision blanking section is finally formed is avoided, anda higher possibility is provided for enabling precision blanking to be more widely applied to high-strength type materials.

The invention discloses a zirconia ceramic plastic processing method assisted by a direct-current electric field. The method comprises the following steps: step 1, stabilizing ZrO2 powder by adoptingY2O3, and carrying out mold pressing and sintering to obtain a 3YSZ sample; step 2, heating the sample to 600-900 DEG C at a heating rate of 10 DEG C/min, and keeping the temperature for 30 minutes; and step 3, applying the direct-current electric field with current density of 50-400 mA/mm<2> to two ends of the sample under a temperature condition of 600-900 DEG C, keeping the direct-current electric field for 5 minutes, and then stretching the sample to complete the plastic processing. According to the invention, an electroplastic effect and an electrocaloric effect under the assistance of the direct-current electric field are utilized, so that deformation resistance in the plastic processing process is reduced while the deformation rate is increased and the environment temperature neededby the plastic processing is reduced, and the elongation rate of the plastic processing is improved.

A MEMS microgravity sensor chip with the quasi-zero stiffness characteristic preloaded based on electric heating comprises a monocrystalline silicon substrate, a silicon dioxide insulating layer growson the monocrystalline silicon substrate, a monocrystalline silicon structure layer is bonded on the silicon dioxide insulating layer, and a MEMS acceleration sensor chip is manufactured in the monocrystalline silicon structure layer; the MEMS acceleration sensor chip comprises a chip frame, four corners of the chip frame are respectively provided with a group of electrode anchor points, an electric heating driving unit composed of V-shaped beams is connected between each group of electrode anchor points, the V-shaped beams are connected with a middle arm, the middle arm is connected with a mass block through a limiting self-locking mechanism and a spring, and the limiting self-locking mechanism is matched with the chip frame; except the electrode anchor points and the chip frame, the monocrystalline silicon substrate and the silicon dioxide insulating layer below the rest part are corroded; an electro-thermal effect is adopted to carry out axial displacement loading on the spring, the mass block obtains a section of working interval with quasi-zero rigidity in the vertical direction on the premise that the vertical rigidity of the spring is not reduced, and the mass block can beused for microgravity acceleration detection and has the advantages of being simple in structure and the like.

The invention discloses a thin-film material with a high electrocaloric effect and a preparation method of the thin-film material. The thin-film material is 0.5 (Ba0.7Ca0.3)TiO3-0.5Ba(Ti0.8Zr0.2)O3-xFe, x is 0.0-0.03. The preparation method comprises the following steps: dissolving barium acetate and calcium acetate in acetic acid, separately dissolving tetra-n-butyl titanate, zirconium isopropoxide and iron nitrate nonahydrate in ethylene glycol monomethyl ether, then mixing and diluting an obtained solution, and cooling the solution to a room temperature to obtain sol; and preparing a thin film by using a spin-coating method, repeating a coating and pretreatment process for multiple times, carrying out annealing treatment on a substrate on which the thin film grows, and cooling to the room temperature to obtain a target thin film. The preparation method of the thin film is mild in preparation environment, low in cost, high in reliability and simple in process; and by the method, thethin-film material with the high electrocaloric effect is expected to be obtained.

The invention relates to a sheet-type micro refrigerator applying a lead-free ferroelectric material. The micro refrigerator comprises a multi-layer structure which is composed of a ferroelectric dialectric layer and a metal electrode layer alternatively; the ferroelectric dielectric layer is made of the lead-free ferroelectric material; periodic square wave signals with alternative changes of working electric fields for controlling the ferroelectric dialectric layer are applied on the metal electrode layer, thus the changes of the working electric fields of the ferroelectric dialectric layer are higher than 100kv/cm. A curtain coating technology is adopted to manufacture the multi-layer thick film structure for the sheet-type micro refrigerator provided by the invention, the high electrocaloric effect is realized through a superelevation electric field condition, and the sheet-type micro refrigerator has the following beneficial effects: 1) environmental protection: a lead-free ferroelectric ceramic is adopted as a working medium, which correponds to the environment protection requirement; 2) high efficiency: the actual refrigerating amount can reach more than 2J/g; and 3) the structure is simple, the production technology is mature, and the cost is low.

A minimal quantity lubrication grinding device including: heat pipe grinding wheel covered with electrocaloric film material on both side surfaces, wherein external electric field is applied to outside of the electrocaloric film material; and electrostatic atomization combined nozzle provided with high-voltage DC electrostatic generator and magnetic field forming device at the outside and in an electrocaloric refrigeration and magnetically enhanced electric field; electrostatic atomization combined nozzle is respectively connected with nanoparticle liquid and gas supply system; and nanofluid is electrostatically atomized by electrostatic atomization combined nozzle and is jet to grinding area to absorb heat of grinding area; electrocaloric film material absorbs heat in grinding area through electrocaloric effect and disperses absorbed heat through heat pipe grinding wheel after leaving grinding area to form a Carnot cycle. Nanofluid electrostatic atomization is integrated with electrocaloric refrigeration and heat pipe.

Technologies are generally described herein for electrocaloric effect heat transfer devices, methods, and systems that may be effective to efficiently transfer and distribute thermal energy from a heat source utilizing coordinated application of out of phase electric signals to adjacent heat transfer stacks coupled with a thermal distribution layer. Some electrocaloric effect heat transfer stacks may include alternating layers of electrocaloric effect material and thermal rectifier material. The out of phase electric signals produce electric fields that bias the electrocaloric effect material of one heat transfer stack to a hot phase, emitting thermal energy, while biasing the electrocaloric effect material of an adjacent heat transfer stack to a cold phase, absorbing thermal energy. The thermal distribution layer allows for thermal energy from the material in the hot phase to be distributed to the material of the adjacent stack in the cold phase rather than back to the heat source.

The invention relates to a morphotropic phase boundary potassium-bismuth titanate-based leadless relaxor ferroelectric ceramic preparation method. The method comprises the following steps: selecting raw materials and performing two-time ball milling, discharging materials, drying the materials, and calcining the materials to obtain ceramic powder, dumping the material in a muffle furnace and performing sintering, and using sand paper with different granularity for grinding sintered ceramic chip to obtain the thin ceramic chip with a flat and bright surface. Compared with the prior art, the ceramic phase structure constitutes rhombohedral phase and tetragonal phase, under effect of an electrical field, a ferroelectric domain is easily overturned, large electrocaloric effect can be obtained,the ceramic can be obtained through a common sintering method, cost is low, and pollution is not generated, the prepared material has electrocaloric effect in a wide temperature area, and has a largeapplication prospect on a solid refrigeration aspect.

The invention discloses a two-phase flow refrigerating device based on an electric heating effect. The device comprises N refrigerating devices with electric heating effect materials, N+1 heat transfer fluid pipelines, low heat conducting fluids, high heat conducting fluids and a power supply; the N+1 heat transfer fluid pipelines and the N refrigerating devices are alternately paved; the two heattransfer fluid pipelines on the outermost side respectively correspond to a heat dissipating end and a refrigerating end; the low heat conducting fluids and the high heat conducting fluids are alternately filled in the heat transfer fluid pipelines by the same volumes; each refrigerating device comprises multiple sections of refrigerating chips, and thermal insulation matters arranged between twoadjacent sections of refrigerating chips; each section of refrigerating chip is connected with the power supply; power supply switches are connected to circuits between each section of refrigeratingchip and the power supply; and the power supply switches corresponding to odd sections of refrigerating chips and even sections of refrigerating chips are alternately turned on and off. The two-phaseflow refrigerating device based on the electric heating effect has the advantages of scientific design, simple structure, continuous heat transfer and improvement of the heat dissipating power and thetemperature span.

The invention discloses a method for preparing SBN (Sr0.5Ba0.5Nb2O6) nano-powder with an improved sol-gel method. According to the method, Nb(OOCCOOH)5, SrCO3 and BaCO3 are taken as raw materials, ammonia water is taken as a precipitating agent, ethylene glycol is taken as an esterifying agent, and citric acid is taken as a metal complexing agent. A preparation process comprises steps as follows: firstly, Nb(OOCCOOH)5 is dissolved in deionized water, excessive ammonia water is added dropwise, and Nb(OH)5 precipitates are obtained; the precipitates subjected to aging, filtering and washing are dissolved with citric acid, and a Nb-citric acid solution is formed; SrCO3 and BaCO3 are dissolved sequentially, and a uniform and transparent Sr-Ba-Nb-citric acid complex is formed; ethylene glycol is added to the complex finally for a polyesterification reaction; a final precursor is subjected to calcination treatment after vacuum drying, and the SBN nano-powder can be obtained. The process of preparing the SBN nano-powder with the method is not involved with a toxic and highly-corrosive chemical reagent, the operation procedure is simple, the preparation cost is low, and the prepared nano-power can be used for preparing SBN ceramics with an electrocaloric effect.

The invention discloses a cooling material with electrocaloric effect, wherein the cooling material comprises 1-50% by mass of a perovskite structure filler and 50-99% by mass of a macromolecule polymer substrate. According to the present invention, the isothermal entropy change and the adiabatic temperature change at 800 KV/cm respectively can reach more than 60 KJ.cm<-3>k<-1> and 9 DEG C, the refrigerant capacity is higher than 0.7 MJ.m<-3>, the actual working temperature range is up to 60 DEG C, and the cooling material has high electrocaloric effect compared with pure ceramics or polymer materials.

The invention relates to the technical field of dielectric materials, in particular to high-tetragonal-phase barium titanate powder, a method for preparing the same, barium titanate thick-film ceramic, a method for preparing the same and application of the barium titanate thick-film ceramic. The specific surface area of the high-tetragonal-phase barium titanate powder ranges from 7.5 m<2>/g to 9.5m<2>/g; the particle size of the high-tetragonal-phase barium titanate powder ranges from 50 nm to 100 nm; the high tetragonal rate c/a of the high-tetragonal-phase barium titanate powder ranges from1.0072 to 1.0092; the tetragonal phase content of the high-tetragonal-phase barium titanate powder ranges from 65% to 80%. The high-tetragonal-phase barium titanate powder, the methods, the barium titanate thick-film ceramic and the application have the advantages that the high-tetragonal-phase barium titanate powder has the small particle size, is high in activity and can be used for preparing ultrathin thick-film ceramic; the barium titanate thick-film ceramic has a high dielectric constant, is high in breakdown field strength and is excellent in electric characteristics as compared with barium titanate thin-film ceramic, excellent electrocaloric effects can be realized by the barium titanate thick-film ceramic, and the thickness of the barium titanate thick-film ceramic can reach the micrometer scale; the barium titanate thick-film ceramic can be used as a component of an MLCC (multilayer ceramic capacitor), and accordingly the performance of the MLCC can be enhanced.