Flexible magnetoelectric piezoelectric switching device, wearable patch and preparation method and application of flexible magnetoelectric piezoelectric switching device and wearable patch

Abstract

The invention provides a flexible magnetoelectric piezoelectric switching device, a wearable patch and a preparation method and application of the wearable patch, and relates to the field of sensors. The device comprises a flexible film substrate, a transducer and a sensor, the transducer, the flexible thin film substrate and the sensor are sequentially coupled to form the flexible magnetoelectric piezoelectric switching device. According to the flexible magnetoelectric piezoelectric switching device prepared by the invention, the piezoelectric characteristic of the flexible film substrate is combined with the magnetoelectric effect of the MENPs, so that the device can accurately control the conversion between the magnetization state and the potential, and ultrahigh controllability is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular, to a flexible magneto-voltage piezoelectric switch device, a wearable patch, a preparation method thereof and an application thereof. Background Art

[0002] In recent years, with the progress of nanomaterial technology, the application of nanoparticles (NPs) in the development of sensing devices has become increasingly widespread. There are various types of NPs materials, including organic NPs such as liposomes and polymeric NPs, and inorganic NPs such as quantum dots, graphene, magnetic NPs and metallic NPs. Many nano-controlled release systems can be combined with these materials, including systems based on thermal, light (ultraviolet), electrochemical and ultrasonic responses. These advanced sensing devices determine their physical environment by monitoring the collective response of NPs to stimuli such as temperature and pressure.

[0003] In particular, multiferroic materials have attracted attention due to the coupling of different ferroic orders and their magnetoelectric effect. Such materials include substances with (anti-) ferromagnetic, ferroelectric, ferroelastic and other properties, and have become a research hotspot driven by the demand for a new generation of high-performance electronic devices. A new type of nanoparticle (NP) based on ferroelectric (FE) and ferromagnetic (FM) properties, namely multiferroic nanoparticles (MFNPs), has been discovered and used for carrier transportation and sensing. Different from traditional magnetic NPs, the core / shell structured composite multiferroic nanoparticles (MFNPs) can achieve low-field on-demand driving due to their magnetoelectric coupling effect, and thus have the advantages of low loss and high energy efficiency. This makes the nano-controlled release system based on magnetoelectric nanoparticles (MENP) have good prospects in sensing and driving applications in biological environments, especially in wearable or implantable systems.

[0004] In addition, such multifunctional nanoparticles can be applied to many solution-based applications. However, due to the uncontrollability of NPs, such as the natural tendency to agglomerate easily, which will weaken the sensing mechanism depending on the surface area or spacing of NPs, making its practical application very limited. On the other hand, wearable sensors and actuators have prospects in monitoring and delivering drugs to target areas. Due to the difficulty of fabricating nanostructures on soft materials, the nanomaterials on wearable devices are still challenging.

[0005] Therefore, there is an urgent need to develop a new type of NPs deposition technology and a multi-field coupling material system to promote the development of wearable sensing technology. Summary of the Invention

[0006] In view of this, the present invention proposes a highly sensitive and super-controllable flexible magneto-voltage piezoelectric switch device, a wearable patch, and their preparation methods and applications. By using the piezomagnetic and piezoelectric properties of flexible magnetoelectric nanoparticles (MENPs), strain sensing in the switch device and wearable patch is achieved. During the preparation process, the demagnetizing field is utilized to align the core-shell MENPs to avoid agglomeration of the nanoparticles, thereby obtaining a flexible magneto-voltage piezoelectric switch device and a wearable patch with good piezoelectric properties, hydrophobicity, and body movement sensing ability.

[0007] The technical solution of the present invention is realized through the following steps:

[0008] In the first aspect, the present invention provides a flexible magneto-voltage piezoelectric switch device, including a flexible thin film substrate, and the flexible thin film substrate includes: a flexible substrate, a piezoelectric substrate, and MENPs;

[0009] The MENPs have a core-shell structure, including a cobalt ferrite magnetic core and a barium titanate piezoelectric shell layer; the MENPs are dispersed in the piezoelectric substrate.

[0010] In one or some possible embodiments, the preparation of the MENPs includes the following steps:

[0011] First, prepare the CoFe2O4 magnetic core by the hydrothermal method; then coat the BaTiO3 shell layer on the surface of the CoFe2O4 magnetic core to form a core-shell structure, and cool to obtain MENPs.

[0012] In one or some possible embodiments, the cooling rate is 14 - 52 °C / min, and the average particle size distribution range of the MENPs is 19 - 31 nm.

[0013] In one or some possible embodiments, the CoFe2O4 particles are prepared by heating and mixing an aqueous solution of a soluble cobalt salt, a soluble iron salt, and polyvinylpyrrolidone dissolved in an aqueous solution of sodium borohydride;

[0014] The BaTiO3 precursor solution is prepared by mixing an aqueous solution containing barium carbonate and citric acid with an ethanol solution containing titanium isopropoxide and citric acid;

[0015] The MENPs are obtained by dispersing the CoFe2O4 particles in the BaTiO3 precursor solution, followed by ultrasonic treatment, drying, and calcination, and then controlling the cooling rate.

[0016] In one or some possible embodiments, the flexible substrate includes a polydimethylsiloxane film, a silver nanowire network, and a polyvinylidene fluoride film;

[0017] The silver nanowire network is embedded on the surface of the polydimethylsiloxane thin film to form a silver nanowire network-embedded polydimethylsiloxane thin film;

[0018] The polyvinylidene fluoride membrane is coated on the surface of the silver nanowire network-embedded polydimethylsiloxane thin film to form a flexible substrate.

[0019] In one or some possible embodiments, the piezoelectric substrate is a polyvinylidene fluoride-trifluoroethylene copolymer thin film.

[0020] In one or some possible embodiments, when the MENPs are dispersed on the surface of the piezoelectric substrate, the MENPs are demagnetized.

[0021] In one or some possible embodiments, the flexible magneto-voltage-electric switch device further includes a transducer and a sensor.

[0022] In a second aspect, the present invention relates to a preparation method of the above flexible magneto-voltage-electric switch device, including the following steps: coupling the transducer, the flexible thin film substrate and the sensor in sequence to obtain the flexible magneto-voltage-electric switch device.

[0023] In one or some possible embodiments, it relates to the application of the above flexible magneto-voltage-electric switch device in wearable sensors, actuators in targeted drug delivery, physical health monitoring and other aspects.

[0024] In a third aspect, the present invention provides a wearable patch, including the above flexible magneto-voltage-electric switch device.

[0025] A flexible magneto-voltage-electric switch device, a wearable patch and their preparation methods and applications provided by the present invention have the following beneficial effects compared with the prior art:

[0026] (1) By optimizing the deposition process of the nanoparticles, the present invention uses the core-shell structured MENPs to achieve multi-field coupling of strain, electric field and magnetic field, significantly improving the sensitivity of sensing and driving. The demagnetization alignment technology is adopted to ensure the uniform distribution and directional arrangement of the nanoparticles on the flexible substrate, effectively avoiding the agglomeration phenomenon of the nanoparticles and improving the stability and reliability of the device.

[0027] (2) The flexible magneto-voltage-electric switch device prepared by the present invention realizes on-demand driving under low-field conditions by using magnetic nanoparticles with a core-shell structure having a high magnetoelectric coupling coefficient, reducing energy loss and improving energy efficiency. By regulating the magnetization state through strain, the dependence on an external magnetic field or electric field is reduced, further reducing power consumption. At the same time, the piezoelectric characteristics of the flexible thin film substrate are combined with the magnetoelectric effect of the MENPs, enabling the device to precisely control the conversion of the magnetization state and the electric potential, achieving ultra-high controllability.

[0028] (3) The flexible magneto-voltage piezoelectric switch device prepared by the present invention has a flexible thin film substrate with good mechanical flexibility and deformation resistance, and can maintain functional stability under extreme bending or humid environments. The surface of the device has superhydrophobic properties, improving the waterproof performance and making it suitable for long-term use of wearable devices in complex environments.

[0029] (4) The flexible magneto-voltage piezoelectric switch device prepared by the present invention forms a "drive-sense-feedback" closed-loop system through the collaborative work of the transducer, flexible thin film substrate, and sensor, and can real-time monitor the response signals of user tissues (such as magnetic field changes, voltage fluctuations), and achieve precise control, suitable for a variety of application scenarios, such as physiological signal monitoring, targeted drug delivery, motion sensing, etc.

[0030] (5) The flexible magneto-voltage piezoelectric switch device prepared by the present invention is applicable to fields such as wearable devices, medical sensors, drug delivery systems, etc., has broad commercial application potential, and can realize functions such as needle-free drug delivery and real-time physiological monitoring, improving the user experience and treatment effect. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 Schematic diagrams of PVDF thin films, their microstructures, PFM images, and flexible thin film substrates provided by one or some embodiments of the present application;

[0033] Figure 2 Simulated electric field and electric potential diagrams generated by PVDF films provided by one or some embodiments of the present application;

[0034] Figure 3 Sample diagrams of PVDF films after polarization provided by one or some embodiments of the present application;

[0035] Figure 4 Images of deposited magnetic nanoparticles and the deposition process provided by one or some embodiments of the present application;

[0036] Figure 5 Diagrams of the change in electric field distribution of magnetic nanoparticles and PVDF films at different distances provided by one or some embodiments of the present application;

[0037] Figure 6Images of magnetic nanoparticles based on the magneto-optical Kerr effect (MOKE) provided for one or some embodiments of this application;

[0038] Figure 7 M-H hysteresis loop diagrams of CoFe2O4 in the form of nanoparticles and thin films provided for one or some embodiments of this application;

[0039] Figure 8 M-H hysteresis loops of magnetic nanoparticles obtained under different stress conditions provided for one or some embodiments of this application;

[0040] Figure 9 Curves of magnetization intensity change and distance dependence diagrams under different stresses provided for one or some embodiments of this application;

[0041] Figure 10 Polarization phenomenon diagrams of PVDF films under different stress conditions provided for one or some embodiments of this application;

[0042] Figure 11 Voltage change diagrams of PVDF films during the polarization process provided for one or some embodiments of this application;

[0043] Figure 12 Characteristic diagrams of magnetic phase changes of PVDF films provided for one or some embodiments of this application;

[0044] Figure 13 Response diagrams of MENPs to voltage changes provided for one or some embodiments of this application;

[0045] Figure 14 XRD diagrams of P(VDF-TrFE) thin films under different sintering conditions provided for one or some embodiments of this application;

[0046] Figure 15 Diagrams of a soft piezoelectric device provided for one or some embodiments of this application;

[0047] Figure 16 Physical characteristic diagrams of a MENP device provided for one or some embodiments of this application;

[0048] Figure 17 Structural diagrams and preparation diagrams of a MENP patch provided for one or some embodiments of this application;

[0049] Figure 18 Performance diagrams of a MENP patch provided for one or some embodiments of this application;

[0050] Figure 19 Schematic diagrams of a rotating nanopatch provided for one or some embodiments of this application;

[0051] Figure 20 Schematic diagram of a nano patch component provided for one or some embodiments of the present application;

[0052] Figure 21 Schematic diagram of three nano patch structures provided for one or some embodiments of the present application;

[0053] Figure 22 Nano patch product provided for one or some embodiments of the present application;

[0054] Figure 23 Schematic diagram of a system containing a PVDF film provided for one or some embodiments of the present application;

[0055] Figure 24 Schematic diagram of a system containing a magnetoelectric effect nanoparticle sensor patch provided for one or some embodiments of the present application;

[0056] Figure 25 Flow schematic diagram of method 1200 provided for one or some embodiments of the present application;

[0057] Figure 26 Functional schematic diagram of a system of a nanoparticle sensor patch provided for one or some embodiments of the present application;

[0058] Figure 27 Characteristic diagram of a nanoparticle sensor patch provided for one or some embodiments of the present application;

[0059] Figure 28 Operating schematic diagram of a nanoparticle sensor patch provided for one or some embodiments of the present application;

[0060] Figure 29 Schematic diagram of the working mechanism of a touch sensor provided for one or some embodiments of the present application;

[0061] Figure 30 Structural characteristic diagram of different layers of a nanoparticle sensing patch provided for one or some embodiments of the present application;

[0062] Figure 31 Sensor actuation mechanism diagram of a nanoparticle sensing patch provided for one or some embodiments of the present application;

[0063] Figure 32 Application diagram of a nanoparticle sensing patch provided for one or some embodiments of the present application;

[0064] Figure 33 Relevant detection diagram of a nanoparticle sensing patch provided for one or some embodiments of the present application;

[0065] Figure 34A nanoparticle sensing patch for drug release applications provided for one or some embodiments of the present application;

[0066] Figure 35 The process diagram of the nanoparticle sensing patch provided for one or some embodiments of the present application during drug release;

[0067] Figure 36 The characteristic illustration diagram of the nanoparticle sensing patch provided for one or some embodiments of the present application for drug transportation;

[0068] Figure 37 The inkjet printing process diagram provided for one or some embodiments of the present application;

[0069] Figure 38 The detailed inkjet printing diagram provided for one or some embodiments of the present application;

[0070] Figure 39 The characteristic illustration diagram of the MENP droplet deposition provided for one or some embodiments of the present application;

[0071] Figure 40 The moving position diagram of the droplets of the particle solution provided for one or some embodiments of the present application;

[0072] Figure 41 The edge region diagram of the droplets provided for one or some embodiments of the present application;

[0073] Figure 42 The uniform droplet deposition diagram on the flexible piezoelectric element provided for one or some embodiments of the present application;

[0074] Figure 43 The uniform droplet deposition diagram on the flexible substrate provided for one or some embodiments of the present application;

[0075] Figure 44 The moving position diagram of small particles and large particles provided for one or some embodiments of the present application;

[0076] Figure 45 The flow chart of spraying magnetic particles provided for one or some embodiments of the present application;

[0077] Figure 46 The detailed diagram of spraying magnetic particles provided for one or some embodiments of the present application;

[0078] Figure 47 The preparation process diagram of the nanoparticle sensing patch provided for one or some embodiments of the present application;

[0079] Figure 48 The particle deposition and magnetic field change diagram provided for one or some embodiments of the present application;

[0080] Figure 49 Example particle types provided for one or some embodiments of the present application;

[0081] Figure 50 Inkjet printing of P(VDF-TrFE) films provided for one or some embodiments of the present application;

[0082] Figure 51 Sintering data graph of P(VDF-TrFE) inkjet printing provided for one or some embodiments of the present application;

[0083] Figure 52 Specific scenario graph of P(VDF-TrFE) inkjet printing provided for one or some embodiments of the present application;

[0084] Figure 53 Structural diagrams of different layers of nanoparticle sensing patches provided for one or some embodiments of the present application;

[0085] Figure 54 Images of nanoparticle sensing patches at different magnifications provided for one or some embodiments of the present application;

[0086] Figure 55 Response characteristic graphs of different types of sensors provided for one or some embodiments of the present application;

[0087] Figure 56 Characteristic graphs of different wearable devices provided for one or some embodiments of the present application;

[0088] Figure 57 Preparation flow chart of a flexible magneto-voltage piezoelectric switch device provided for one or some embodiments of the present application. Detailed implementation manners

[0089] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0090] The following special explanations are made for the relevant performance tests below:

[0091] (1) Simulation experiment

[0092] COMSOL Multiphysics is used to simulate the strain-induced ME (magnetoelectric) effect based on a flexible thin-film substrate, where the flexible substrate is a cuboid with dimensions of 10μm×10μm×1μm, and the core radius of the MENPs is 0.1μm and the shell radius is 0.2μm.

[0093] In the simulation model, applying stress to the flexible substrate generates an electric field outside it. Under the action of this electric field, the shell ferroelectric material of the MENPs generates strain due to the electrostrictive effect, and this strain is further transmitted to the core ferromagnetic material, thereby changing its magnetization state through the inverse magnetostrictive effect, that is, the ME effect.

[0094] (2) SEM and TEM characterization

[0095] Transmission electron microscopy (TEM) images were obtained using a transmission electron microscope with an accelerating voltage of 200 kV. The experiment used a field emission gun equipped with an imaging filter (Gatan, GIF200) and running DigitalMicrographTM software. The TEM samples were prepared by dropping a small emulsion on a carbon-coated copper (Cu) grid and drying under ambient conditions.

[0096] (3) Scanning probe microscope (SPM)

[0097] Scanning electron microscopy (SEM, JEOL9000F) was carried out for characterization at an accelerating voltage of 15 kV and a working distance of 5 mm. The SPM study was carried out using a Bruker-Nano AFM system in non-contact mode. The magnetic force microscope (MFM) measurement was carried out in dynamic lift mode, and the lift distance was adjusted for modulation.

[0098] This application provides a flexible magneto-voltage piezoelectric switching device, including a flexible thin film substrate, and the flexible thin film substrate includes: a flexible substrate, a piezoelectric substrate and MENPs;

[0099] The flexible substrate includes a polydimethylsiloxane film, a silver nanowire network and a polyvinylidene fluoride film;

[0100] The piezoelectric substrate is a polyvinylidene fluoride-trifluoroethylene copolymer film;

[0101] The MENPs are of core-shell structure, including a cobalt ferrite magnetic core and a barium titanate piezoelectric shell layer; the MENPs are dispersed on the surface of the piezoelectric substrate;

[0102] In an embodiment of this application, the piezoelectric substrate and the MENPs dispersed on the surface of the piezoelectric substrate form a piezoelectric layer.

[0103] In an embodiment of this application, a three-layer composite structure flexible thin film substrate is provided, as Figure 1 shown in a. It can be seen from the figure that: the upper layer and the lower layer are both flexible substrates, which are used to provide structural support and flexibility to ensure the stability and durability of the device in a complex environment; the middle layer is a piezoelectric layer, which uses its piezoelectric effect to realize the conversion between mechanical stress and electrical signals, thereby improving the sensitivity of sensing and driving.

[0104] In one embodiment of the present application, a flexible substrate is provided, including the following steps:

[0105] Mix Sylgard 184 (PDMS precursor) and CLA (curing agent) in a mass ratio of 10:1 to form a homogeneous solution, and anneal it at 150 °C for 10 min to obtain a cured PDMS film; then spray and embed a silver (Ag) nanoparticle solution with a mass fraction of 15% into the PDMS substrate, and cure it at 60 °C for 30 minutes to prepare a flexible PDMS substrate.

[0106] In the embodiment of the present application, in order to improve the mechanical tolerance performance of the flexible substrate under various deformation conditions, a nanocomposite based on a silver nanowire network is used as an intrinsically stretchable interconnect material.

[0107] In one embodiment of the present application, an ethanol solution of the AgNW network (where the mass-volume ratio of the silver nanowire network to ethanol is 10 mg:1 ml) is deposited on a polyethylene naphthalate (PEN) substrate by spraying, and then the PEN substrate deposited with AgNW is placed on an uncured PDMS film. After curing at 100 °C for 1 h, the PEN is peeled off to obtain an AgNW network-embedded polydimethylsiloxane film. Among them, the uncured PDMS film is prepared by mixing Sylgard 184 (PDMS precursor) and CLA (curing agent) in a mass ratio of 20:1 to form a homogeneous solution and annealing it at 150 °C for 10 min.

[0108] Furthermore, to promote the transfer of the AgNW network, a self-assembled monolayer (SAM) (1H,1H,2H,2H-perfluorooctyl) silane (FOTS) is pre-deposited on the surface of the PEN substrate as an anti-adhesion layer.

[0109] In order to further obtain a composite material with excellent piezoelectric properties to meet the strict requirements of high-performance wearable devices or other related fields, the preparation of the flexible substrate is further adjusted.

[0110] In the embodiment of the present application, the flexible substrate includes but is not limited to PVDF film, PZT film, P(VDF-CTFE), etc.

[0111] In one embodiment of the present application, a flexible substrate is provided, including the following preparation steps: Dissolve PVDF in a mixed solvent of DMF (N,N-dimethylformamide) and acetone (where the volume ratio of DMF to acetone is 10:1) to prepare a PVDF dispersion with a mass fraction of 2.5%, and coat the PVDF dispersion on the AgNW network-embedded polydimethylsiloxane film treated with UVO (ultraviolet ozone) for 50 min to prepare a flexible substrate.

[0112] Further, the coating method is spin coating.

[0113] The applicant conducted the following performance tests on the prepared flexible substrate (also known as "PVDF film"), including:

[0114] (1) The flexible substrate was observed and measured using PFM (piezoresponse force microscopy), and the results are as Figure 1 shown in b. From Figure 1 b, it can be seen that the longitudinal piezoelectric coefficient d33 of the film ranges from -24 pC / N to -30 pC / N.

[0115] (2) The potential, electric field distribution, and microstructural changes after polarization treatment of the PVDF film under different strain conditions were analyzed through experiments and simulated electric fields. The results are as Figure 2 and Figure 3 shown.

[0116] By applying different stresses or strains to the PVDF film, different electric fields will be generated in the PVDF film due to the inverse piezoelectric effect.

[0117] In one or some embodiments of the present application, Figure 2 a shows the relationship curve between the z-direction electric field generated by the PVDF film and the z coordinate when a small bending stress is applied to the PVDF film. This data was obtained through COMSOL simulation. At the same time, the potential distribution diagrams of the PVDF film from the side and top views are shown in the inset.

[0118] In one or some embodiments of the present application, Figure 2 b is a comparison diagram of the electric fields generated by the PVDF film under different strain conditions. By comparing the electric field distributions generated by the PVDF film under four different stress conditions, it shows that as the stress amplitude increases, the generated electric field intensity also increases.

[0119] In one or some embodiments of the present application, Figure 3 Shows 5x, 10x, 20x, and 50x magnified views of the PVDF film after polarization treatment. The control of the magnetoelectric switch is realized by utilizing the inverse piezoelectric effect of the PVDF film. Specifically, by applying an external electric field, the PVDF film will deform, thereby changing its internal magnetization state. Due to the antiparallel arrangement of dipoles, the α-phase PVDF film neither has ferroelectric properties nor piezoelectric properties. However, the α-phase is the most easily obtained PVDF morphology. Therefore, before practical application, it is necessary to polarize it by applying a high electric field to transform it from the α-phase to the β-phase, thereby obtaining the required ferroelectricity and piezoelectric properties.

[0120] In the embodiments of the present application, in order to control the magnetism of MENPs through the applied electric field (E-field), a P(VDF-TrFE) film capable of converting mechanical stimuli into electrical signals is used as the piezoelectric layer. The preparation of the P(VDF-TrFE) film includes the following steps:

[0121] Dissolve the P(VDF-TrFE) copolymer in a mixed solvent, and spin-coat it on a pretreated flexible substrate to form a film, thereby obtaining the P(VDF-TrFE) film.

[0122] In one embodiment of the present application, the preparation of the P(VDF-TrFE) film includes: spin-coating a 20 wt% P(VDF-TrFE) solution in methyl ethyl ketone (MEK) onto a PDMS substrate embedded with AgNWs at a speed of 1000 rpm, and then annealing at 140 °C for 1 h under vacuum to obtain a highly crystalline P(VDF-TrFE) film.

[0123] In the embodiments of the present application, the preparation of the MENPs includes the following steps:

[0124] First, prepare a magnetic core by a hydrothermal method; then coat a shell layer on the surface of the magnetic core to form a core-shell structure, and cool to obtain the MENPs.

[0125] In one embodiment of the present application, the magnetic core includes but is not limited to other multi-magnetic materials such as CoFe2O4, NiFe2O4, etc.; the shell layer is selected from ferroelectric materials such as BaTiO3, BiFeO3, PZT (Pb(Zr,Ti)O3), etc.

[0126] In one embodiment of the present application, the preparation of the MENPs includes the following steps:

[0127] First, prepare a CoFe2O4 magnetic core by a hydrothermal method; then coat a BaTiO3 shell layer on the surface of the CoFe2O4 magnetic core to form a core-shell structure, and cool to obtain the MENPs.

[0128] In one embodiment of the present invention, by reducing the cooling rate, that is, using a CMF1100 control furnace to reduce from above 52 °C / min to below 14 °C / min), the average diameter of the MENPs can be controlled from less than 25 nm to greater than 100 nm, and the particle size distribution is controlled within 30%. The particle size distribution is measured by the Zetasizer Nano series using the standard dynamic light scattering (DLS) method.

[0129] Furthermore, the cooling rate is 14 - 52 °C / min, and the average particle size distribution range of the MENPs is 19 - 31 nm.

[0130] In one embodiment of the present application, the CoFe2O4 particles are prepared by heating and mixing an aqueous solution of a soluble cobalt salt, a soluble iron salt, and polyvinylpyrrolidone in an aqueous solution of sodium borohydride;

[0131] The BaTiO3 precursor solution is prepared by mixing an aqueous solution containing barium carbonate and citric acid with an ethanol solution containing titanium isopropoxide and citric acid;

[0132] The MENPs are prepared by dispersing the CoFe2O4 particles in the BaTiO3 precursor solution, followed by ultrasonic treatment, drying, and calcination, and then controlling the cooling rate.

[0133] Further, the preparation of the CoFe2O4 nanoparticles includes: dissolving an aqueous solution (15 mL) of 0.058 g of Co(NO3)2·6H2O, 0.16 g of Fe(NO3)3·9H2O, and 0.2 g of polyvinylpyrrolidone (PVP) in 5 mL of an aqueous solution containing 0.9 g of sodium borohydride (NaBH4), and reacting at 120 °C for 12 hours to obtain CoFe2O4 nanoparticles.

[0134] Further, the preparation of the BaTiO3 precursor solution includes: mixing 30 mL of an aqueous solution containing 0.029 g of barium carbonate (BaCO3) and 0.1 g of citric acid with 30 mL of an ethanol solution containing 0.048 mL of titanium isopropoxide (Ti(OiPr)4) and 1 g of citric acid to obtain the BaTiO3 precursor solution.

[0135] Further, the preparation of the CoFe2O4@BaTiO3 (CFO@BTO nanoparticles) core-shell structured MENPs includes: dispersing 0.1 g of CoFe2O4 nanoparticles in the BaTiO3 precursor solution, ultrasonic dispersing the mixture for 2 hours, continuously stirring and drying at 60 °C overnight, then calcining at 780 °C for 5 hours, and cooling at a rate of 14 °C / min to obtain MENPs with an average particle size distribution range of about 19 - 31 nm.

[0136] To verify the design and performance of the flexible magneto-voltage piezoelectric switch device and to elaborate in detail on the working mechanism, manufacturing process, and characteristics of the device. In the embodiment of the present application, in order to utilize the unique magnetoelectric coupling effect of these particles to enhance or endow the material with new functional characteristics, MENPs are deposited on the surface of a piezoelectric substrate, namely a P(VDF-TrFE) film.

[0137] In one embodiment of the present application, dispersing the MENPs in the piezoelectric layer specifically includes:

[0138] The MENPS solution (prepared by dispersing CoFe2O4 particles in the BaTiO3 precursor solution) was deposited on the surface of the polyvinylidene fluoride-trifluoroethylene copolymer film by a drop-casting method.

[0139] To fully disperse the magnetic nanoparticles, further, the magnetic particles were uniformly deposited on the surface of the P(VDF-TrFE) film by a spraying method, and the MENPs solution was diluted with ethanol at a volume ratio of 1:10. The image of the magnetic nanoparticles deposited on the surface of the P(VDF-TrFE) film is shown in Figure 4 Figure a; Meanwhile, the entire preparation process flow is detailed in Figure 4b.

[0140] In an embodiment of the present application, Figure 5 Figure 5 shows the variation diagrams of the electric field distribution between the composite nanoparticles (NPs) and the PVDF film at different distances, including (A) 0 nm, (B) 10 nm, (C) 20 nm, and (D) 40 nm. As the distance increases, the external electric field generated outside the PVDF film gradually decreases. Figure 5 It intuitively shows the trend that the electric field around the NPs weakens with the increase of the distance, and this change leads to the decrease of the magnetization intensity. Therefore, by adjusting the distance between the NPs and the PVDF film, the magnetization state of the NPs can be effectively controlled.

[0141] In an embodiment of the present application, Figure 6 Figure 6 shows the images of the NPs based on the magneto-optical Kerr effect (MOKE), reflecting the change of the magnetization state of the NPs with the increase of the stress applied on the piezoelectric substrate.

[0142] In an embodiment of the present application, Figure 7 (a) and Figure 7(b) respectively show the M-H hysteresis loops of CoFe2O4 in the form of nanoparticles (NP) and thin film. Compared with the nanoparticles, the CoFe2O4 thin film has a higher saturation magnetization intensity. In addition, Figure 7 (b) shows that when the size of the nanoparticles is 100 nm, CoFe2O4 has the highest saturation magnetization intensity, while when the size is reduced to 10 nm, the saturation magnetization intensity decreases significantly.

[0143] In an embodiment of the present application, Figure 8 Figures 8a-d show the M-H hysteresis loops obtained under different stress conditions. First, a vertically upward magnetic field was applied in the simulation model and scanned from 0 A / m to 105 A / m, and the simulations were performed for four stress conditions (tensile, compressive, bending, and shear), respectively.

[0144] Stresses of different magnitudes have a significant impact on the M-H hysteresis loop of magnetic nanoparticles (NPs). As the applied stress increases, the M-H curves in the cases of tension, bending, and shear gradually become smoother, while the M-H curve in the case of compression becomes steeper. The reason for this phenomenon can be observed in Figure 8 b, which shows that the direction of the electric field generated in the case of compression is opposite to that in other cases. In the cases of tension, bending, and shear, the direction of the electric field generated by the PVDF film is almost parallel to the direction of the externally applied magnetic field. Therefore, the electrostrictive effect of the ferroelectric shell causes a shape change in the core magnetic nanoparticles, thereby promoting the magnetization process. On the contrary, in the case of compression, this effect hinders the occurrence of magnetization.

[0145] In one embodiment of the present application, Figure 9 a and 9b respectively show (a) the curve of the magnetization intensity varying with the Z coordinate under different stress magnitudes, and (b) the distance-dependent curve of the magnetization intensity varying with the Z coordinate (here, the distance refers to the spacing between the PVDF substrate and the center of the composite nanoparticles). As Figure 8 b and Figure 2 show, under the same stress conditions, the electric field generated by the bending stress is stronger than that in other stress cases. Therefore, even a small stress can effectively change the magnetization state. Therefore, applying bending stress is a more efficient magnetization switching method and will be described in detail as an example in the subsequent analysis of the simulation results.

[0146] Figure 9 a shows that as the stress magnitude increases, the magnetization intensity increases correspondingly and finally reaches the saturation magnetization intensity. Based on this, a stress-induced magnetoelectric switch can be realized.

[0147] Figure 9 b shows that as the distance increases, the magnetization intensity decreases correspondingly. The main reason can be obtained from the electric field distribution diagrams at (A) 0 nm, (B) 10 nm, (C) 20 nm, and (D) 40 nm in Figure 5 .

[0148] In the present application, in order to manipulate the magnetism of MF nanoparticles through the generated electric field, a P(VDF-TrFE) film is used to achieve the conversion of mechanical stimulation and electrical energy.

[0149] In one or some embodiments of the present application, as Figure 10 shows, the polarization phenomenon under different stress conditions of the flexible substrate is provided.

[0150] In one or some embodiments of the present application, as Figure 11 shows, the voltage change during the polarization process of the flexible substrate is provided.

[0151] In one or some embodiments of the present application, as Figure 12 shown, the characteristics of the flexible substrate magnetic phase change are provided.

[0152] Furthermore, Figure 13 the response of MENPs to voltage changes is demonstrated.

[0153] In the present application, in order to achieve wearable characteristics and controllable functions, the flexibility and inverse piezoelectric effect of P(VDF-TrFE) thin films are utilized so that high-quality flexible β-phase P(VDF-TrFE) thin films can be fabricated to form a piezoelectric substrate.

[0154] In one or some embodiments of the present application, the XRD measurement results of P(VDF-TrFE) thin films at different sintering temperatures (A) and sintering times (B) are provided, as Figure 14 shown. It can be seen from the figure that the optimized sintering conditions are 140 °C and a sintering time of 1 hour.

[0155] In one embodiment of the present application, a conceptual diagram of a soft piezoelectric device composed of AgNW electrodes and P(VDF-TrFE) thin films is provided, as Figure 15 shown in a. It can be seen from the figure that the AgNW network in the AgNW network embedded PDMS substrate is well dispersed, and the P(VDF-TrFE) thin film is well crystallized.

[0156] Figure 15 b shows the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analysis results of P(VDF-TrFE). Through the XRD spectrum, based on the peaks under different sintering time conditions, the β-phase crystal structure of PVDF is confirmed because the peak at 2θ = 20.26° is related to the diffraction of the β-phase at (110) and (200). The FTIR spectrum shows vibration bands at 840 cm -1 −1, 1279 cm -1 −1 and 1400 cm -1 −1, further verifying the existence of this crystal structure, indicating that the P(VDF-TrFE) substrate can generate an electric field uniformly.

[0157] To further activate the piezoelectric material, a direct current (DC) polarization process is performed on the P(VDF-TrFE) thin film by applying a DC voltage to align the surface bound charges. This process is as Figure 15 shown in c, which provides a schematic diagram of a high-voltage polarization process and its piezoelectric operation under mechanical deformation, explaining how to align the surface bound charges by applying a DC voltage to activate the piezoelectric material, including: when a mechanical stimulus is applied to the piezoelectric device, the electrons on the surface will move on the electrical load, generating an electrical signal.

[0158] Figure 15 d shows the piezoelectric properties of the polarized piezoelectric device. As can be seen here, under mechanical stimulation, the device can generate a voltage output of 0.1 to 1.5 V, demonstrating its effective energy conversion ability.

[0159] To study multifunctional nanoparticles (NPs) on wearable surfaces, the optimization of the spacing of nanoparticles and their optimal response under strain, electric field, or magnetization were investigated. In this patch, strain-tuned magnetization is the key factor. In other words, the electric, magnetic, and elastic fields need to be coupled with the lowest energy loss. Between the magnetostrictive effect and the piezoelectric effect, the magnetoelectric effect (ME effect) of the core / shell structured nanoparticles is achieved through an applied strain. The piezoelectric element includes a P(VDF-TrFE) film and BTO (barium titanate), and follows a linear strain-charge constitutive relationship. In addition, to accurately describe the magnetization state characteristics of magnetostrictive materials, a nonlinear isotropic model was adopted for CFO (cobalt ferrite).

[0160] In one embodiment of the present application, a MENP device is provided, and the physical properties of the device are tested and analyzed as follows. The spacing optimization was tested to avoid possible interference to check the above effects. The test and analysis results are as Figure 16 shown.

[0161] In one embodiment of the present application, when stress is applied to the P(VDF-TrFE) film, the electric field changes of nanoparticles with a diameter of 20 nm at different nanoparticle spacings are as Figure 16 shown in a. As can be seen from the figure: as the particle spacing increases, the electric field potential first increases and then tends to saturate. This indicates that optimizing the spacing between MENPs is crucial for avoiding possible interference and maximizing the electric field effect.

[0162] In one embodiment of the present application, different types of stress are applied to the P(VDF-TrFE) film, and the electric field that generates magnetization through the P(VDF-TrFE) film is analyzed for four deformation modes: bending, compression, tension, and shear stress. The results Figure 16 are shown in b. Figure 16 b shows the calculated simulation results of the potential changes generated by different types of stress (including bending, compression, shear, and tensile deformation modes). The M-E relationship from the P(VDF-TrFE) film to the CFO nanoparticles was studied. The nanoparticle distribution density needs to be high enough to induce magnetization, which provides a technical basis for the reliability of the wearable patch.

[0163] In one embodiment of the present application, the relationship between the magnetization and the electric potential of MENPs on the patch was analyzed, as Figure 16As shown in c, the magnetization state of (CFO) nanoparticles as a function of the electric potential and stress on the PVDF substrate was specifically investigated. The magnetization states corresponding to different stress levels were also characterized by low-torque magnetic force microscopy (MFM) in the figure, illustrating the conversion mechanism from stress to electric potential to magnetization.

[0164] Combined with Figure 16 the deformation mode results shown in b and Figure 16 c, according to the MF curve, the electric potential generated at the same stress level can overcome the threshold voltage, thus reaching saturation magnetization more quickly.

[0165] In one or some embodiments of the present application, as Figure 17 and 18 shown, MENPs are deposited on the surface of a P(VDF-TrFE) film coated on a flexible substrate and the MENPs are aligned by applying a demagnetizing field.

[0166] In one embodiment of the present application, a controllable ME nanopatch is provided, as Figure 17 shown in a. Among them, the PVDF film is used as a substrate to control the magnetism of the MF nanoparticles. Through structural optimization, the P(VDF-TrFE) film is used to control the magnetism of the MENPs deposited thereon, and the nanoparticles can be arranged by applying a demagnetizing field. An MF nanocomposite film is prepared, in which BTO-CFO nanoparticles are uniformly dispersed in the PVDF film.

[0167] AFM and transmission electron microscopy (TEM) were used to analyze the dynamic changes of the above-mentioned step MENPs, and the results are as Figure 17 shown in b. It can be seen from the figure that the MENPs can be aligned by manipulating the demagnetizing field. The AFM image on the right shows that the neat arrangement of the MENPs can be achieved by controlling the trend of the coffee ring effect by adjusting the demagnetizing field. The TEM image on the right shows the composite structure of the MENPs, and its size is about 20 nm. The core is the FM material CFO, and the shell is the FE material BTO. Due to the high magnetoelectric coupling coefficient, the MENPs with a core-shell composite structure are used as the MENPs.

[0168] In one embodiment of the present application, a CFO@BTO nanoparticle with a core / shell structure is provided, as Figure 17 shown in c. Due to the magnetoelectric effect, the particles can convert magnetization into electric potential, and conversely, the BTO shell can convert electric potential into magnetization. Figure 17c provides the ideal characteristics of CFO@BTO nanoparticles: inside the MENPs, the ferromagnetic CFO particles are in a state of synchronous orientation of atomic magnetic moments. However, due to the presence of the outer BTO shell, it is polarized under the action of an external electric field, and opposite charges are generated at both ends of the nanoparticle shell. This magnetoelectric effect (ME effect) enables the nanoparticles to achieve the conversion from magnetization to electric potential; conversely, the BTO layer can also convert the electric field into magnetization.

[0169] The P(VDF-TrFE) film is used as a piezoelectric substrate to control the magnetic properties of the MENPs deposited on its surface, where the nanoparticles can be aligned by applying a demagnetizing field. The nanoparticles with a core-shell composite structure are used for MENPs due to their high magnetoelectric coupling coefficient.

[0170] Figure 17 d shows a schematic diagram of the multiferroic mechanism in this case. By applying a force, the change in electric potential in the P(VDF-TrFE) film and the BTO shell result in a change in magnetization in the CFO core. The red / blue arrows represent the changes in the directions of the electric field and magnetization. After applying strain, an electric field is generated, aligning the BTO shell. Then, the direction of magnetization is subsequently controlled. Figure 17 d demonstrates the final MENP patch function after optimizing the nanoparticles (NPs), P(VDF-TrFE), and the nanoparticles deposited on P(VDF-TrFE): in the absence of mechanical load, the piezomagnetoelectric switch does not produce a response, that is, the magnetic moments are randomly oriented, as shown at the top of Figure 17 d. When stress ( Figure 17 the black arrow at the bottom of d) is applied to the PVDF, an electric potential (green arrow) is generated outside it, thus activating the BTO shell of the MENPs and causing it to deform due to the electrostrictive effect. This strain is further transmitted to the internal CFO particles, making the directions of the magnetic moments tend to be consistent due to the magnetostrictive effect. The red / blue arrows represent the changes in the magnetization direction (upward and downward directions / north and south directions) respectively.

[0171] After successfully optimizing the manufacturing process, we tested the overall device function of the MENP patch.

[0172] Figure 18 a - m show the characteristics and performance of the MENP patch.

[0173] Figure 18a - e show the hydrophobicity experiment of the patch and its analysis over time (from left to right). As time progresses, the angle between the water droplet and the surface contact line increases from 95° to 128°. For wearable devices, hydrophobicity is crucial for improving surface reliability and can effectively prevent the device from being affected by aqueous solutions. In addition, this property enables the device to be washable, thereby enhancing the usability of the MENPs patch in practical applications. It is worth noting that the contact angle increases with time (from Figure 18 95° in a to Figure 18 128° in e).

[0174] In one embodiment of the present application, a magnetic field sensing MENP device integrated with a micro - Hall sensor array is presented, as shown in Figure 18 f. The generated magnetic field is observed in real - time through the installed micro - Hall sensor array to confirm the magnetization output. The sensors are arranged in a 3×3 matrix within the MENP region, as shown in Figure 18 f. The magnetic signals induced by human motion are transmitted to the MENPs through PVDF and sensed through the change in the electric field between the MENPs and the sensors.

[0175] Figure 18 g shows the piezoelectric echo signal after pulse generation, indicating the performance of the MENP patch in electric - field - driven magnetization. By applying an alternating magnetic - field pulse, the corresponding electric - field response can be observed. Figure 18 The first and second magnetic echo signals after the piezoelectric effect can be seen in g. This result confirms that the interface between the MENPs and the piezoelectric substrate is well - connected and functioning properly. As shown in Figure 18 c, the generated electric potential causes magnetization. In this configuration, the reverse conversion from magnetization to electric field is also observed. The received electrical signal is attributed to the elastic deformation of P(VDF - TrFE), which is caused by the uniform magnetization of the particles.

[0176] Figure 18 h shows the spin - echo signal after the transducer pulse.

[0177] To study the signal changes during wearing, we conducted wearable motion tests by fixing the MENP patch on the human body. The magnetic - field response induced by human motion was observed, and the relevant results are shown in Figure 18 i.

[0178] Figure 18 i and Figure 18 j respectively show the elbow - flexion and elbow - extension modes. During flexion, the elbow joint drives the forearm towards the shoulder joint until the hand is level with the shoulder (such as in a bicep curl motion). During extension, the elbow joint straightens, causing the hand to move downward.

[0179] Figure 18i shows the voltage response of the patch under magnetic field changes.

[0180] Figure 18 j shows a schematic diagram of a human body model and gait analysis. The force estimated based on human movement is about 75 N. As Figure 18 shown in i, an electric field range of 120 A / m is observed. Details of the gait analysis are given in the supplementary material section. The experimental test results are in good agreement with the simulation analysis. Next, we use a magnetic field sensor to detect the magnetic field generated by human movement.

[0181] Figure 18 k - 18m show the measurement results of the magnetic field response induced by human movement. In different modes, the magnetic field response distribution is observed using the patch fixed on the triceps brachii. The test results from contraction (low tension) to relaxation (high tension) are shown in Figure 18 k (low tension), Figure 18 l (medium tension) and Figure 18 m (high tension) respectively. The magnetic field response indicates that the human movement magnetoelectric sensor operates stably and reliably.

[0182] In one embodiment of the present application, a spin - nano patch is as Figure 19 shown.

[0183] In one embodiment of the present application, the component parts of a nano patch are as Figure 20 shown.

[0184] In some embodiments of the present application, three nano - patch structures are as Figure 21 shown.

[0185] In some embodiments of the present application, exemplary products of the nano patch are as Figure 22 shown.

[0186] In one embodiment of the present application, as Figure 23 shown, a system is provided, where PVDF is used both as a transceiver and as a receiver.

[0187] Furthermore, the MENP sensing patch 1000 includes a sensing and transducer component 1002 and a flexible thin - film substrate PVDF / PDMS 1004 (abbreviated as "thin - film substrate (PVDF / PDMS) 1004"). The sensing and transducer component 1002 includes a transducer 1006 and a sensor 1008.

[0188] During operation, the microcontroller (MCU) 1010 sends an input signal to the transducer 1006, which generates a transducer output signal and inputs it to the thin-film substrate (PVDF / PDMS) 1004, thus forming an output signal that is subsequently received by the user's tissue.

[0189] The user's tissue generates a response signal 1018, which returns to the thin-film substrate (PVDF / PDMS) 1004, and then forms a sensing input signal and inputs it to the sensor 1008. The sensor 1008 generates a sensing output signal and returns it to the MCU 1010.

[0190] The MCU 1010 transmits the sensing output signal to the server 1012 through the communication interface 1014. The communication interface 1014 uses Wi-Fi or Bluetooth communication based on human body communication. The server 1012 is responsible for storing data and further processing the data to analyze the behavior of cancer cells.

[0191] In one embodiment of the present application, a system including a magnetoelectric effect nanoparticle (MENP) sensing patch 1000 (as Figure 23 shown) is as Figure 24 shown in a. The patch 1000 consists of a substrate 1004, MENP 1102, a transducer 1006, and a Hall sensor 1104. The transducer 1006 is connected to the flexible thin-film substrate 1004 and receives a transducer input signal from the MCU 1010, and then generates a transducer output signal 1016, which is transmitted to the user's tissue. In one embodiment, the transducer input signal can be a sine wave, a square wave, or other waveform signals with a specific peak level.

[0192] The response signal 1018 of the user's tissue is received by the Hall effect sensor 1104, and the output signal generated by the sensor is transmitted to the MCU 1010. The Hall voltage is measured from the signal of the MENP particles.

[0193] Furthermore, the MCU 1010 generates a digital signal for detecting a specific tissue condition by detecting the voltage difference between the transducer input signal and the sensor output signal.

[0194] In one embodiment of the present application, a circuit for generating the output signal 1016 is as Figure 24 shown in b. The signal waveforms shown in the circuit are as Figure 24 shown in c - d.

[0195] Figure 24 e - j show the signal waveforms generated and received in the Figure 24 system shown in a. In different embodiments, the transducer signal can be a sine wave, a square wave, and / or a single-pulse signal.

[0196] In one embodiment of the present application, as Figure 25 shown: A method 1200 for operating the MENP sensing patch 1000 is shown (as Figure 24 shown). It includes:

[0197] Step 1202: Generate a transducer signal on the MCU device.

[0198] Step 1204: Input the transducer signal into the transducer connected to the flexible thin film substrate.

[0199] Step 1206: The transducer receives the transducer input signal and generates an output signal, which is transmitted to the user tissue through the flexible thin film substrate.

[0200] Step 1208: The Hall effect sensor receives the response signal of the user tissue, and this sensor is connected to the flexible thin film substrate.

[0201] Step 1210: The Hall effect sensor converts the tissue response signal into a sensor output signal.

[0202] Step 1212: The sensor output signal is input into the MCU.

[0203] Therefore, the method 1200 enables the magnetoelectric effect nanoparticle sensing patch 1000 to provide a transducer signal to the user tissue and process the tissue response signal. It should be noted that the operation process of the method 1200 is only an example, and the specific steps can be reordered, increased, decreased, or modified according to the implementation requirements.

[0204] In one embodiment of the present application, the various functional capabilities of a system including a nanoparticle sensing patch are as Figure 26 shown.

[0205] In one embodiment of the present application, the related characteristics of the nanoparticle sensing patch are as Figure 27 shown.

[0206] In one embodiment of the present application, the working mechanism of a nanoparticle sensing patch is as Figure 28 shown in a.

[0207] In one embodiment of the present application, the voltage measurement results of the Hall effect sensor for the nanoparticle sensing patch mechanism are as Figure 28 shown in b.

[0208] In one embodiment of the present application, a schematic diagram of the working mechanism of a touch sensor is as Figure 29 shown in a, showing the process from touch to signal reading.

[0209] In one embodiment of the present application, a schematic diagram of a matrix measurement characteristic is asFigure 29 As shown in Figure b, it shows the signal changes during touch. The number of matrices can be increased as needed. Including multiple matrices can detect different shapes and materials (hardness) and ensure ultra-high-sensitivity touch detection.

[0210] In one embodiment of the present application, a method for planar surface measurement is as Figure 29 shown in Figure c.

[0211] In one embodiment of the present application, a method for curved surface measurement is as Figure 29 shown in Figure d.

[0212] In one embodiment of the present application, a schematic diagram of a machine learning algorithm for determining a stop point is as Figure 29 shown in Figure e.

[0213] In one embodiment of the present application, a method for statistical analysis with zero error using machine learning is as Figure 29 shown in Figure f.

[0214] In some embodiments of the present application, the structural characteristics of different layers of the nanoparticle sensing patch are as Figure 30 shown.

[0215] In one embodiment of the present application, the sensor actuation mechanism of the nanoparticle sensing patch is as Figure 31 shown.

[0216] In one or some embodiments of the present application, a nanoparticle sensing patch and various application positions on human tissues are as Figure 32 shown.

[0217] In one embodiment of the present application, the detection characteristics of the nanoparticle sensing patch are as Figure 33 shown, indicating that strain causes magnetization change.

[0218] In one embodiment of the present application, a nanoparticle sensing patch for drug release applications is as Figure 34 shown.

[0219] Furthermore, Figure 35 it shows the characteristics of the nanoparticle sensing patch during drug release.

[0220] In one embodiment of the present application, the characteristics of the nanoparticle sensing patch during nicotine drug release are as Figure 36 shown.

[0221] In one embodiment of the present application, as Figure 37 shown, a method for depositing MENP droplets on a flexible substrate during an inkjet printing operation is provided.

[0222] In one embodiment of the present application, as Figure 38 shown, a method for an inkjet printing operation for depositing MENP droplets on a flexible substrate is provided.

[0223] In one embodiment of the present application, as Figure 39 shown, detailed characteristics of the deposition of MENP droplets formed during an inkjet printing process are provided.

[0224] In one embodiment of the present application, as Figure 40 shown, a method for the placement and movement of particulate solution droplets is provided.

[0225] Furthermore, as Figure 41 shown, the edge region of the droplet is demonstrated.

[0226] In one embodiment of the present application, as Figure 42 shown, a method for uniform droplet deposition on a flexible piezoelectric element is provided.

[0227] Furthermore, Figure 43 the situation of uniform droplet deposition on a flexible substrate is demonstrated.

[0228] Furthermore, Figure 44 the movement and stabilization methods of small and large particles are illustrated.

[0229] In one embodiment of the present application, as Figure 45 shown, a method for spraying magnetic particles is provided.

[0230] Furthermore, Figure 46 a detailed view of spraying magnetic particles is demonstrated.

[0231] In one or some embodiments of the present application, as Figure 47 shown, several methods and processes for forming a nanoparticle sensing patch are provided.

[0232] In one or some embodiments of the present application, as Figure 48 shown, a method for how particles are uniformly deposited to cause a magnetic field change due to mechanical strain is provided.

[0233] In one or some embodiments of the present application, as Figure 49 shown, exemplary particle types are provided.

[0234] In one embodiment of the present application, as Figure 50 shown, a method for inkjet printing of P(VDF-TrFE) is provided.

[0235] Furthermore, Figure 51 the sintering conditions for inkjet printing of P(VDF-TrFE) are demonstrated.

[0236] In one embodiment of the present application, as Figure 52 shown, a scenario of performing P(VDF-TrFE) inkjet printing on a soft platform is provided.

[0237] In one or some embodiments of the present application, different layer structures of the nanoparticle sensing patch, such as Figure 53 shown.

[0238] Furthermore, Figure 54 images of the nanoparticle sensing patch at different magnifications are shown.

[0239] In one or some embodiments of the present application, the response characteristics of different types of sensors are as Figure 55 shown.

[0240] In one or some embodiments of the present application, the characteristics of different wearable devices are as Figure 56 shown.

[0241] In an embodiment of the present application, as Figure 57 shown, the preparation method of the flexible magneto-voltage piezoelectric switch device includes: coupling the transducer, the flexible thin film substrate and the sensor in sequence to obtain the flexible magneto-voltage piezoelectric switch device.

[0242] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A flexible magneto-voltage piezoelectric switching device, characterized in that Comprising a flexible thin-film substrate, the flexible thin-film substrate comprising: a flexible substrate, a piezoelectric substrate, and magnetoelectric nanoparticles; The magnetoelectric nanoparticles have a core-shell structure, comprising a cobalt ferrite magnetic core and a barium titanate piezoelectric shell layer; the magnetoelectric nanoparticles are dispersed on the surface of the piezoelectric substrate.

2. The flexible magneto-voltage piezoelectric switch device according to claim 1, wherein, The preparation of the magnetoelectric nanoparticles comprises the following steps: Preparing a CoFe2O4 magnetic core by a hydrothermal method; then coating a BaTiO3 shell layer on the surface of the CoFe2O4 magnetic core to form a core-shell structure, and cooling to obtain the magnetoelectric nanoparticles.

3. The flexible magneto-voltage piezoelectric switch device according to claim 2, wherein, The cooling rate is 14 - 52 °C / min, and the average particle size distribution range of the magnetoelectric nanoparticles is 19 - 31 nm.

4. The flexible magneto-voltage piezoelectric switch device according to claim 3, wherein The CoFe2O4 particles are prepared by heating and mixing an aqueous solution of a soluble cobalt salt, a soluble iron salt, and polyvinylpyrrolidone in an aqueous solution of sodium borohydride; The BaTiO3 precursor solution is prepared by mixing an aqueous solution containing barium carbonate and citric acid with an ethanol solution containing titanium isopropoxide and citric acid; The magnetoelectric nanoparticles are obtained by dispersing the CoFe2O4 particles in the BaTiO3 precursor solution, followed by ultrasonic treatment, drying, calcination, and controlling the cooling rate.

5. The flexible magneto-voltage piezoelectric switch device according to claim 1, characterized in that, The flexible substrate comprises a polydimethylsiloxane film, a silver nanowire network, and a polyvinylidene fluoride film; The silver nanowire network is embedded on the surface of the polydimethylsiloxane film to form a silver nanowire network-embedded polydimethylsiloxane film; The polyvinylidene fluoride film is coated on the surface of the silver nanowire network-embedded polydimethylsiloxane film to form a flexible substrate.

6. The flexible magneto-voltage piezoelectric switch device according to claim 1, wherein The piezoelectric substrate is a polyvinylidene fluoride-trifluoroethylene copolymer film.

7. The flexible magneto-voltage piezoelectric switch device according to claim 1, characterized in that, When the magnetoelectric nanoparticles are dispersed on the surface of the piezoelectric substrate, the magnetoelectric nanoparticles are demagnetized.

8. The flexible magneto-voltage piezoelectric switch device according to claim 1, characterized in that The flexible magnetoelectric piezoelectric switch device further comprises a transducer and a sensor.

9. A method for preparing a flexible magneto-voltage piezoelectric switching device as claimed in claim 8, characterized in that, The transducer, the flexible thin-film substrate, and the sensor are sequentially coupled to obtain a flexible magnetoelectric piezoelectric switch device.

10. Application of the flexible magnetoelectric piezoelectric switch device prepared by the preparation method according to claim 9 in wearable devices, medical sensors, and drug delivery systems.

11. A wearable patch, characterized in that, Comprising the flexible magnetoelectric piezoelectric switch device prepared by the preparation method according to claim 9.

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