11 results about "Ferroelectret" patented technology

The invention discloses a waterproof and anti-corrosion fluorine-containing ferroelectret and a preparation method thereof, and belongs to the cross technical field of functional polymer materials and flexible electronic technologies. The fluorine-containing ferroelectret is prepared by carrying out edge fusion packaging on an upper dense polymer film, a lower dense polymer film and a middle layer and then carrying out corona polarization treatment, and the middle layer is of a porous polymer film single-layer structure or a porous polymer film and dense polymer film alternate arrangement structure. The fluorine-containing ferroelectret and the preparation method thereof have the advantages that the structure regulation and the edge melting composite process of the porous fluorine-containing multilayer polymer film are innovated, so that the prepared fluorine-containing ferroelectret not only has flexibility, high temperature resistance and excellent piezoelectricity (greater than or equal to 400pC / N), but also has waterproof and anti-corrosion capabilities, and after electrodes are connected to the two opposite sides of the electret, the performance of the electret is greatly improved. The sensor is suitable for sensing, acoustics and energy collection scenes in harsh environments such as high temperature and brine corrosion.

A multilayer piezoelectret film element, a polymeric porous sheet, and a method for preparing them are disclosed. The present disclosure ensures that the gas can be ionized without damaging the polymeric porous sheet by adjusting the gap between pores and the dielectric strength of the polymeric porous sheet in the multilayer piezoelectret film element. The polymeric porous sheet has a high piezoelectric constant after electric polarization and surface metallization treatment, and can generate a significant amount of charge under mechanical pressure, thereby exhibiting high sensitivity in applications such as piezoelectric sensors, and solving the problems of low piezoelectric activity and fast loss of piezoelectric activity of the polarized polymeric piezoelectret film element in the art. Moreover, the production process is simple, which can ensure continuous production of the polymeric piezoelectret film element.

The invention belongs to the technical field of intelligent wearable equipment, and particularly relates to a negative Poisson's ratio piezoelectric electret-based insole and a preparation method and application thereof, the insole comprises a piezoelectric electret support structure, a conductive electrode layer and a protective layer; the piezoelectric electret supporting structure is a porous matrix layer made of an electret material or a porous matrix layer of which the surface is coated with an electret layer; the piezoelectric electret supporting structure is a negative Poisson's ratio structure; the conductive electrode layer is coated on the surface of the piezoelectric electret supporting structure, and the conductive electrode layer is connected with an electrode lead; and the protective layer is packaged outside the piezoelectric electret supporting structure and the conductive electrode layer. Compared with the prior art, the problem that in the prior art, an intelligent insole can only achieve a single effect and cannot meet the requirements of diabetic feet for multiple functions is solved. According to the scheme, dynamic monitoring, impact resistance and high comfort are integrated, and an innovative solution is provided for early screening of diabetic feet, ulcer risk assessment and intervention treatment early warning.

The present application discloses a method for preparing a piezoelectric sensor and a piezoelectric sensor. The preparation method includes: providing a piezoelectric electret; disposing a signal array unit on one side surface of the piezoelectric electret; disposing an insulating layer on the area of the piezoelectric electret surface not covered by the signal array unit; making a signal conductor on the insulating layer and connecting the signal conductor to the signal array unit; and disposing a ground layer and a ground conductor on the side surface of the piezoelectric electret away from the signal array unit to obtain a piezoelectric sensor. Through the above-mentioned method, the present application can reduce the restrictions on the size of the piezoelectric sensor caused by the number and size of the sensing units, and reduce the impact of the number and size of the sensing units on the detection accuracy. By increasing the density of the array units in the sensor, the precision and accuracy of the sensing signal can be further improved.

The invention provides a flexible piezoelectric electret device, a preparation method of the flexible piezoelectric electret device and a piezoelectric sensor. The flexible piezoelectric electret device comprises a piezoelectric main body and a packaging assembly which completely wraps the piezoelectric main body, the piezoelectric main body comprises a first electrode, a negative polarity flexible laminated assembly, an intermediate dielectric layer with a micro-nano pore structure, a positive polarity flexible laminated assembly and a second electrode which are sequentially laminated from bottom to top; wherein the negative polarity flexible laminated assembly is prepared by sequentially laminating a plurality of negative polarity electret films along the homo-polarity direction and performing a physical compounding process; and the positive flexible laminated assembly is prepared by sequentially laminating a plurality of positive electret films along the same polarity direction and carrying out a physical compounding process. The flexible piezoelectric electret device provided by the invention can break through the technical bottleneck after structure and configuration optimization, can finally adapt to wearable skin electronics, implantable medical monitoring and other high-requirement application scenes, and has the potential of large-scale mass production.

The invention relates to a flexible piezoelectric vital capacity tester and a preparation method, the tester comprises a blowing nozzle, a hose and a metal shell which are sequentially arranged from left to right, and an air storage bag, a piezoelectric sensing element, a data processing element and a display screen are arranged in the metal shell; the piezoelectric sensing element comprises a flexible material layer taking a piezoelectric electret metamaterial as a core sensing material, an electrode and a wire, and is attached to the outer wall of the air storage bag; in the expansion process, deformation of the airbag body is converted into an electric signal, and the piezoelectric sensing element has an excellent negative Poisson's ratio auxetic characteristic, can synchronously generate isotropic tensile deformation along with expansion of the air storage bag, and is tightly attached to the outer wall of the air storage bag in a gapless manner; the data processing element is electrically connected with the piezoelectric sensing element and is used for conditioning, sampling and calculating the electric signal and obtaining vital capacity parameters according to the electric signal; and the display screen is electrically connected with the data processing element and is used for displaying a test result.

This invention provides a polarization method for a porous piezoelectric electret material. The porous piezoelectric electret material includes a porous polymer film, a first electrode, and a second electrode, with the porous polymer film disposed between the first and second electrodes. This invention identifies the minimum and maximum thickness pores among multiple pores in the porous piezoelectric electret material to be polarized. Based on the Poisson breakdown voltage curve obtained from the Townsend model, the gas pressure inside the pores is adjusted in order of decreasing or increasing thickness, and an optimal breakdown voltage is applied synchronously and continuously for polarization. This ensures that pores of different thicknesses can be polarized at the same voltage value, thereby avoiding the need to apply higher polarization voltages to polarize pores that deviate from the optimal breakdown thickness, and the risk of breaking down the porous polymer film due to applying higher polarization voltages.

This invention discloses a gateless organic thin-film transistor controlled by a piezoelectric electret and its fabrication method, relating to the field of organic electronics technology. The method includes: obtaining a polypropylene film; treating the polypropylene film by thermal expansion and then subjecting the thermally expanded polypropylene film to corona polarization to obtain a porous polypropylene piezoelectric electret film; depositing a pentaphenyl semiconductor layer on the surface of the porous polypropylene piezoelectric electret film to form an organic semiconductor layer; depositing source and drain electrodes on the organic semiconductor layer using a photomask; depositing an encapsulation layer on at least a portion of the surface of the source electrode, at least a portion of the surface of the drain electrode, at least a portion of the surface of the organic semiconductor layer, and between the source and drain electrodes; and leading out the source and drain electrodes using wires. This invention integrates the advantages of passive piezoelectric tactile sensing with transistor signal amplification through the coupling of piezoelectric effect, field effect, and semiconductor properties, realizing a direct, active human-machine interaction mode.

The purpose of the present invention is to provide a flexible piezoelectric corneal contact lens for repairing corneal damage, which belongs to the field of biomedical device technology. While avoiding secondary corneal damage caused by eyelid friction, the corneal contact lens converts the energy of daily blinking mechanical motion into an external electric field through a piezoelectric electret film, a rectifier and an electrode pair, thereby enhancing the endogenous electric field generated by the organism to repair the cornea. Without the need for external additional energy supply, it can achieve the effect of regulating the microenvironment of the damaged cornea, alleviating matrix fibrosis, promoting the orderly migration and regular arrangement of epithelial cells, alleviating corneal limbal stem cell deficiency, and restoring corneal clarity. At the same time, the core structure of the present invention, the piezoelectric electret film, adopts a 12-pointed star-shaped snowflake structure, which can effectively improve the robustness and stretchability of the structure, as well as the sensitivity and power generation density of the sensor.

The invention relates to the technical field of medical detection, and discloses an intelligent blood pressure and heart rate monitor which is characterized in that a contact layer is provided with a reversible microneedle array and thermal response shape memory gel, and the contact layer can penetrate through clothes and fill carpal gaps; the sensing layer is provided with a piezoelectric electret film and an acoustic metamaterial resonant ring, and pulse signals are enhanced through mechanical deformation conversion and physical filtering; the control layer is integrated with a fold type extension circuit board and a miniature negative pressure bag, supports bending deformation of the wrist and maintains skin adsorption of equipment. According to the scheme, clothes interference is eliminated through the microneedle array, the thermal response gel compensates for human body structure differences, the acoustic metamaterial improves the signal-to-noise ratio of weak signals, the negative pressure bag structure inhibits dynamic slippage, and the wearing comfort, the movement stability and the complex environment adaptability are improved while non-invasive measurement is guaranteed.

The invention discloses a multilayer polymer piezoelectric electret material and a preparation method thereof. The preparation method comprises the following steps: respectively preparing a fiber membrane and a cast membrane through electrostatic spinning and a solution tape casting method; covering the surface of the fiber membrane with a cast film, and alternately overlapping layer by layer to obtain a multi-layer P (VDF-TrFE) electret; carrying out superposition and corona polarization treatment on a plurality of layers of P (VDF-TrFE) electrets; and testing d33 of the piezoelectric electret material after polarization. According to the preparation method, a solution tape casting method, an electrostatic spinning method and corona polarization are creatively combined, the prepared multi-layer P (VDF-TrFE) piezoelectric electret material has good flexibility and mechanical strength, the piezoelectric constant d33 of an electret is tested, the maximum piezoelectric constant test reaches 3314 pC / N, and the product shows high piezoelectric response.