Multiphase soft metal elastomer direct-current generator and preparation method thereof

Abstract

The invention belongs to the technical field of wearable energy, and particularly relates to a multiphase soft metal elastomer direct-current generator and a preparation method thereof. The direct-current generator comprises a flexible porous dielectric layer, a liquid metal embedded layer, an electret encapsulation layer, a bottom electrode layer and a top electrode layer. The liquid metal embedded layer is formed by printing liquid metal on the lower surface of the flexible porous dielectric layer, the bottom electrode layer is arranged on the lower surface of the liquid metal embedded layer, the top electrode layer is arranged on the upper surface of the flexible porous dielectric layer, and the electret packaging layer is fixed on the upper surface of the top electrode layer. A solid-liquid-gas three-phase interface is constructed, elasticity modulus matching of a multi-phase interface and built-in electric field driving force are formed, a friction electricity-ion charge division cooperation interface based on the flexible porous dielectric layer / liquid metal embedded layer is achieved, high-voltage and direct-current output is achieved, and the device has the advantages of being high in output, good in stability, simple in structure and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of wearable energy, and in particular relates to a multiphase soft metal elastomer DC generator and a preparation method thereof. Background Art

[0002] Efficient flexible power sources are essential for flexible and wearable electronics. To address current challenges, such as limited stability and the need for repeated charge and discharge, it is necessary to develop advanced materials and construct novel devices to improve the safety performance of flexible power sources.

[0003] Liquid metal is an emerging type of electronic architecture for soft matter systems, with rich sensing, motion, control, communication, interactive computing and other functions. The main function of liquid metal elastomers is to realize information energy perception, that is, the conversion of mechanical energy to electrical energy. Conversely, the mechanical motion interaction of liquid metal materials can also be controlled by energy input, such as external field-controlled robot motion and self-driving behavior. There are several potential solutions to achieve efficient conversion of mechanical energy to electrical energy, such as elastomer generators based on the electric double layer (EDL) principle (Adv. Mater. 2021, 2103142) and electrochemical generators (Adv. Funct. Mater. 2023, 2309177). Efforts to improve this flexible power source are mainly to improve the power-to-weight ratio and power density (current density). The open circuit voltage and short circuit current of the electric double layer generator and elastomer generator depend on the material and device structure of the dielectric elastomer (Rare Metals. 2023, 1186.). In addition, the electromotive force of the electrochemical generator depends on the electrolyte reaction pool, and the charge transfer or redox reaction is limited by the material concentration, type and mechanical response frequency-time sensitivity. This is because the traditional EDL double-layer power generation device requires sufficient deformation due to the working principle. According to the capacitor formula C=Q / Δt, the amount of charge is related to the rate of change of capacitance. Although this can adapt to the soft and discrete mechanical energy collection and utilization of the human body, its flexibility is still limited. Similarly, the electrochemical mechanism generator uses the redox process to provide a potential difference to drive the movement of charges, but this process consumes metals to achieve continuous power supply.

[0004] In addition, in the above-mentioned flexible power generation devices, designing a flexible and stretchable system is a key goal. Liquid metal has been widely used as a flexible electrode. Although high output performance has been achieved, the current work still has the following limitations: (1) Liquid metal must form a composite conductive material with a polymer to exert its electrical function; (2) The bulk material of the liquid metal requires the design of a dielectric elastomer package or a barrier layer of the electrochemical cell to prevent short circuits; (3) The fluidity and adhesion of liquid metal as a liquid electrode are prone to leakage; (4) As a mechanical energy collection scenario, it can only be applied to low-frequency situations; (5) Such structures usually require larger dielectric layer / electrode stress-deformation or contact separation to achieve effective charge separation.

[0005] Therefore, there is an urgent need to develop a universally printable liquid metal material to solve the leakage problem of liquid metal, achieve integrated integration with a flexible substrate, and ultimately prepare a highly stable flexible friction nanogenerator. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a multiphase soft metal elastomer DC generator, comprising a flexible porous dielectric layer, a liquid metal embedding layer, an electret packaging layer, a bottom electrode layer and a top electrode layer. The liquid metal embedding layer is obtained by printing liquid metal on the lower surface of the flexible porous dielectric layer, the bottom electrode layer is placed on the lower surface of the liquid metal embedding layer, the top electrode layer is placed on the upper surface of the flexible porous dielectric layer, and the electret packaging layer is fixed on the upper surface of the top electrode layer.

[0007] The solid-liquid-gas three-phase interface thus constructed specifically refers to the flexible porous dielectric layer as the solid skeleton part, which has a certain porosity and provides high-density spatial friction charges.

[0008] The liquid metal embedded layer is specifically a solid-liquid mixed layer. The lower surface of the flexible porous dielectric layer treated with plasma has a certain wettability. Therefore, in the process of printing a thin layer of liquid metal on its surface, most of the liquid metal penetrates into the shallow pores on the lower surface of the flexible porous dielectric layer due to the surface capillary force and pressure, thereby forming a continuous conductive surface on the lower surface of the flexible porous dielectric layer; while the wettability of the interior of the flexible porous dielectric layer to the liquid metal is weakened, and at the same time, the wetting area has surface tension and blocking effects on the liquid metal film. Therefore, the anchoring effect of the liquid metal embedded layer is achieved through the difference in wettability and the synergy of surface tension.

[0009] The spatial gradient of the continuous distribution of the solid-liquid-gas three-phase boundary generates a gradient-changing in-situ electrostatic field, specifically the spatial friction charge inside the flexible porous dielectric layer and the arrangement structure of the ionic charge inside the liquid metal embedding layer. In addition, the flexible porous dielectric layer is thin and flexible as a whole, so we call this interface a "multiphase soft metal interface."

[0010] In addition, due to the continuous distribution mechanism of the solid-liquid-gas three-phase interface boundary, the flexible porous dielectric layer / liquid metal embedded layer has a high effective contact area, and the double electric layer microstructure is sensitive to external pressure / stress in shear, strain / effective contact area changes, and has an elastomer-like effect. The mechanical-electrical coupling path of the double electric layer capacitance coupling formed by this mechanism has a high stress transfer efficiency. Therefore, we call this interface mechanism the "multiphase soft metal elastomer mechanism."

[0011] Through the above mechanism, when the device is triggered by external mechanical force, based on the elastic modulus matching of the multiphase interface and the driving force of the built-in electric field, the friction charges form a conductive channel in the flexible porous dielectric layer, while the ionic charges migrate directionally through the double electric layer diffusion layer. Therefore, the entire system forms a closed loop, thereby achieving the separation of friction charges and ionic charges.

[0012] Based on the frictional electric-ionic charge division of labor and cooperation interface of the above-mentioned flexible porous dielectric layer / liquid metal embedded layer, high voltage and direct current output is achieved, which has the advantages of high output, good stability, simple structure and low cost.

[0013] Furthermore, the liquid metal is a gallium-indium-tin system and one or more of the following metals: bismuth, gold, silver, copper, zinc and aluminum.

[0014] Furthermore, the material of the flexible porous dielectric layer is one or more of porous polytetrafluoroethylene and electrospun nanofiber.

[0015] Furthermore, the thickness of the liquid metal embedding layer is less than 10 microns.

[0016] Furthermore, the material of the electret packaging layer is one or more of polytetrafluoroethylene, polyvinylidene fluoride, perfluoroethylene propylene, and polydimethylsiloxane.

[0017] Furthermore, the material of the bottom electrode layer and the top electrode layer is conductive silver cloth.

[0018] Furthermore, the area of ​​the top electrode layer is smaller than the area of ​​the electret encapsulation layer, and the electret encapsulation layer covers the top electrode layer and the flexible porous dielectric layer.

[0019] Furthermore, the top electrode layer is in a strip shape, and the length of the top electrode layer is the same as the length of the electret packaging layer.

[0020] On the other hand, the present invention provides a method for preparing a multiphase soft metal elastomer DC generator, comprising the following steps: Step 1, preparing liquid metal of target proportion; Step 2: placing liquid metal on the flexible porous dielectric layer to form a liquid metal embedded layer; Step 3: a bottom electrode layer is arranged on the lower surface of the liquid metal embedding layer, a top electrode layer is arranged on the upper surface of the flexible porous dielectric layer, and an electret packaging layer is arranged on the surface of the top electrode layer to construct a multiphase soft metal elastomer DC generator.

[0021] Furthermore, in step 2, the liquid metal is scraped onto the flexible porous dielectric layer using a stainless steel rod.

[0022] Beneficial effects of the present invention: The present invention forms a continuous distribution interface composed of a solid phase, a liquid phase and a gas phase through the spatial arrangement of a flexible porous dielectric layer and a thin layer of liquid metal. The upper part of the interface is the porous fiber surface of the flexible porous dielectric layer, which is distributed with spatial friction static charges, while the lower part is the double electric layer ion charge of the interface of the flexible porous dielectric layer / liquid metal thin layer, and the separation of friction charge-ion charge is achieved under the drive of the built-in electric field. Therefore, from the electrical function, the electrical function of the present invention is the direct current output generated by the division of labor and cooperation mechanism of friction charge-ion charge.

[0023] The present invention uses the electrodes arranged on the upper surface of the flexible porous dielectric layer and the electrodes at the interface of the liquid metal thin layer as two output terminals respectively. When the device is static, the resistance between the two electrodes reaches 300GΩ, which is an open circuit state. When the device is working, due to the directional migration of the friction charge-ion charge driven by the excitation of the friction electric field, a dynamic discharge conductive channel is established inside the flexible porous dielectric layer, thereby generating a DC output current. Therefore, the flexible porous dielectric layer / liquid metal thin layer interface constructed by the present invention can be equivalent to an equivalent circuit of several micro-capacitors in parallel, and the multi-phase interface is in a parallel relationship as a whole, so the present invention does not have the short circuit problem caused by local liquid metal leakage.

[0024] The flexible porous dielectric layer / liquid metal thin layer in the present invention has an anchoring effect as a whole. Since the flexible porous dielectric layer has a certain porosity, there is an air gap inside. On the one hand, since the liquid metal thin layer is different from the liquid metal of the conventional bulk material, and since the thickness of the embedded layer is less than 10μm, it has no fluidity. On the other hand, when the device is deformed by external pressure / stress, due to the non-wetting property of the flexible porous dielectric layer in the vertical direction, the liquid barrier effect, and the surface tension of the liquid metal embedded layer, the interface has a self-encapsulation characteristic, so there will be no liquid metal leakage problem.

[0025] (4) The present invention constructs a continuous distribution boundary of the solid-liquid-gas three-phase interface of a porous flexible dielectric layer / liquid metal thin layer, and because the double electric layer charge arrangement structure is at the submicron level, it has a quasi-resonant cavity effect, which enables the present invention to further enhance charge transfer under ultrasonic excitation, thereby enhancing the current output amplitude. Therefore, the present invention has the beneficial effect of simultaneously collecting mechanical vibration energy and ultrasonic energy in the contact-separation mode; (5) At the same time, since the present invention induces a relatively high double-layer charge density in the vertical direction of the solid-liquid interface, the interface stress transfer efficiency is relatively high. When the device is subjected to pressure / stress, a strong friction electric field is excited through the solid-liquid-gas interface, thereby achieving effective charge separation.

[0026] Based on the above beneficial effects, the present invention has good application prospects in the field of wearable energy technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a multi-phase soft metal elastomer DC generator.

[0028] Figure 2 It is a schematic diagram of the device structure and output performance.

[0029] Figure 3 It is the charge transfer mechanism at the multiphase interface.

[0030] Figure 4 It is a diagram of the DC power generation working mechanism of the device.

[0031] Figure 5 It is the characterization of the layered liquid metal interface structure embedded in porous polytetrafluoroethylene and the current diagram under different output modes.

[0032] Figure 6 It is a graph of the device's pressure and frequency response output voltage signal.

[0033] Figure 7 It is the resistance signal of the device under different pressures.

[0034] In the figure: 1. bottom electrode layer; 2. liquid metal embedding layer; 3. flexible porous dielectric layer; 4. top electrode layer; 5. electret encapsulation layer. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0036] The present invention provides a multi-phase soft metal elastomer DC generator, such as Figure 1As shown, it includes a flexible porous dielectric layer 3, a liquid metal embedding layer 2, an electret encapsulation layer 5, a bottom electrode layer 1 and a top electrode layer 4. The liquid metal embedding layer 2 is obtained by printing liquid metal on the lower surface of the flexible porous dielectric layer 3. The liquid metal is a gallium indium tin system and one or more of the following metals: bismuth, gold, silver, copper, zinc and aluminum. The material of the flexible porous dielectric layer 3 is one or more of porous polytetrafluoroethylene (PTFE porous membrane) and electrospun nanofibers. The thickness of the liquid metal embedding layer 2 is less than 10 microns. The bottom electrode layer 1 is placed on the lower surface of the liquid metal embedding layer 2. The top electrode layer 4 is placed on the upper surface of the flexible porous dielectric layer 3. The electret encapsulation layer 5 is fixed on the upper surface of the top electrode layer 4. The material of the electret encapsulation layer 5 is one or more of polytetrafluoroethylene, polyvinylidene fluoride, perfluoroethylene propylene, and polydimethylsiloxane. The electret encapsulation layer 5 plays the role of encapsulation and protection at the same time. The bottom electrode layer 1 and the top electrode layer 4 are made of conductive silver cloth, and the bottom electrode layer 1 and the top electrode layer 4 are connected by an external wire to form a closed loop. The area of ​​the top electrode layer 4 is smaller than the area of ​​the electret encapsulation layer 5, and the electret encapsulation layer 5 covers the top electrode layer 4 and the flexible porous dielectric layer 3. Specifically, the top electrode layer 4 is strip-shaped, and the length of the top electrode layer 4 is the same as the length of the electret encapsulation layer 5. Preferably, the top electrode layer 4 is a strip conductor line, and the strip conductor line is arranged in parallel on the surface of the flexible porous dielectric layer 3. The material of the ring conductor line is silver cloth. The thickness of the strip conductor line is 0.01mm-0.05mm.

[0037] The core concept of the invention is to use liquid metal printing to form a thin liquid embedding layer on the lower surface of a flexible PTFE porous membrane. Through the integrated triboelectric and multiphase liquid metal elastomer synergistic effect, a triboelectric-ion interface coupling mechanism of a solid-liquid-gas multiphase interface is proposed to achieve a high output of liquid metal triboelectronics with liquid phase-DC-high voltage field effect. In the contact-separation mode, the voltage exceeds 1kV.

[0038] like Figure 2As shown, the present invention forms a high charge density reservoir by constructing a continuous distribution boundary of the solid-liquid-gas three-phase interface of a porous flexible dielectric layer / liquid metal thin layer. And because the double electric layer charge arrangement structure in the interface is at the submicron level (usually less than 100nm). Therefore, when the interface is stimulated by external contact / non-contact pressure / stress or mechanical waves, electric fields and other excitation sources, the double electric layer charge density can be further enhanced, inducing double electric layer boundary oscillation / shear to generate more non-equilibrium carriers, and enhancing the output current, thus having a quasi-resonant cavity effect. At the same time, the multiphase elastomer interface and the liquid metal thin layer form an interface equivalent series capacitor, and the flexible porous dielectric layer 3 / air gap and the flexible porous dielectric layer 3 / liquid metal embedded layer 2 produce spatial charge distribution, and the spatial friction charge-ion charge has a coupling relationship. When stimulated by an external field, under the action of the electric field, the friction electrons are transmitted through the flexible porous dielectric layer 3, and the liquid metal charge produces directional ion migration, and the friction charge and the ion charge form a division of labor and cooperation interface.

[0039] Specifically, Figure 3 The charge division of labor and cooperation interface mechanism principle of the present invention is given: Figure 3 (a) is the structure of the double-layer charge distribution. The charge distribution characteristics of the multiphase interface can be divided into three stages. In stage i, the double-layer distribution of the liquid metal embedded layer 2 caused by the initial charge of the PTFE porous membrane, at this time, the charge density is relatively low. In stage ii, with the contact charging mechanism caused by mechanical energy stimulation or continuous external field excitation, the charge density of the multiphase interface will increase. In stage iii, when negative charges continue to be injected, the double-layer charge of the liquid metal embedded layer 2 restores its original polarity, and more positive charges are distributed in the diffusion layer.

[0040] To verify the above mechanism, two different modes were used to test the charge transfer characteristics. First, the contact-separation mode (2 Hz) was used, and then the ultrasonic excitation was applied to the back side of the device after a delay of 2 seconds. Figure 3 The results shown in (b) show that as the number of contact separations increases, the charge shows a gradual upward trend, indicating significant charge accumulation at the interface. We define this process as the charging stage and represent it as +Q; then use ultrasound as the excitation source, and the charge generated at this time is defined as the reverse charging stage and represented as -Q. It can be seen that due to the blocking characteristics of the interface electric field, the device exhibits the characteristics of unidirectional charge transfer.

[0041] In addition, we designed a charge injection experiment using an electrostatic bias source. Inspired by the photovoltaic carrier separation and recombination mechanism, we explored the effect of initial charge excitation on the intrinsic electric field of the solid-liquid-gas multiphase interface. The electrostatic gun was used as an electrostatic bias source to control the positive and negative bias voltages and was connected to the liquid metal embedding layer 2 and the positive electrode of the electrometer. Figure 3 As shown in (cd), the output current quickly changes from negative to positive, which is attributed to the diffusion layer charge of the non-equilibrium charge output caused by the instantaneous negative electric field impact. With the polarity reversal, the output current turns into a positive pulse. The universality of a similar mechanism is also demonstrated when the negative electrode is used as a charge injection window. Due to the blocking effect of the multiphase interface electric field, the injected charge is captured and stored in the shallow layer of the PTFE porous membrane. At this solid-liquid interface, ions with opposite polarity are attracted, thereby outputting a certain negative current. Subsequently, with the change of the external electric field, the current is converted into a positive pulse again.

[0042] Figure 4 This is a schematic diagram of the device's DC generator mechanism. Unlike the traditional contact-separation mode, the charge excitation mode is related to the field effect. This DC mode can be regarded as a parallel circuit on the interface, so its output is proportional to the contact area. In order to prove this charge output and frequency response limit, we designed a system consisting of an ultrasonic generator and a transducer as an external field excitation source, which can further increase the charge density of the device and thus improve its power generation performance.

[0043] The present invention provides a method for preparing a multiphase soft metal elastomer DC generator, comprising the following steps: Step 1: Prepare liquid metal of target proportion. Specifically, first, gallium, indium and tin metal particles are mixed in a mass ratio of 67:20.5:12.5, and stirred for 10 minutes using a mixer. Next, the mixture is heated to 100°C under nitrogen protection, kept for 12 hours, and then naturally cooled to room temperature to obtain Ga 67 In 20.5 Sn 12.5 Finally, by adjusting the mass ratio of GaInSn and Cu, the mixture was heated to 250°C in a nitrogen atmosphere and kept at this temperature for 72 hours, and then naturally cooled to obtain GaInSnCu multiphase metal, in which the mass fraction of Cu was 10%.

[0044] Step 2: placing liquid metal on the flexible porous dielectric layer 3 to form a liquid metal embedded layer 2. Specifically, the liquid metal is scraped onto the flexible porous dielectric layer 3 using a stainless steel rod.

[0045] Step 3, a bottom electrode layer 1 is set on the lower surface of the liquid metal embedding layer 2, a top electrode layer 4 is set on the upper surface of the flexible porous dielectric layer 3, and an electret encapsulation layer 5 is set on the surface of the top electrode layer 4 to construct a multiphase soft metal elastomer DC generator. Specifically, a piece of polytetrafluoroethylene film with a size of 3.0 cm×2.5 cm is taken as the encapsulation friction layer. The surface of the PTFE membrane is plasma treated (time is 300s, the atmosphere is oxygen) to improve its wettability. The prepared polytetrafluoroethylene membrane is used as the outermost encapsulation layer, and the scraped PTFE porous membrane / liquid metal embedding layer 2 is used as the underlying structure. The PTFE porous membrane adopts a film with a thickness of 2-3μm and a porosity of 60%. Then, a conductive silver cloth (30mm×3mm) is pasted on the upper surface of the PTFE porous membrane as the upper electrode, and the output end of the liquid metal embedding layer 2 is connected to the conductive silver cloth for charge collection bottom electrode.

[0046] Figure 5 (a) is a scanning electron microscope (SEM) image of the multiphase interface and an EDS elemental energy spectrum image. Figure 5 (b) is the charge distribution mechanism of the multiphase interface, and the output signal obtained by exchanging the two electrodes in the positive and negative directions to verify the DC output characteristics. As can be seen from the figure, due to the existence of the interface electric field, the output current is the largest when the liquid metal side of the DC output electrode is the positive output terminal, reaching 40 microamperes.

[0047] The output performance of the multi-phase soft metal elastomer DC generator prepared in Example 2 of the present invention under different modes was verified. Figure 6 (a) and Figure 6 (b) is the open circuit voltage and short circuit current signal when triggered by different pressures. It can be seen that the output of the device is related to the pressure threshold. The signal is smaller at lower pressures (voltage 180V, current 2μA), and the output signal is significantly increased at higher pressures (voltage 600V, current 30μA). Figure 6 (c) is the load power curve of the generator, the maximum power of the device reaches 7.16W / m 2 In addition, frequency-related performance test results such as Figure 6 As shown in Figures 6(d) and 6(e), it can be seen that as the frequency increases, the amplitudes of voltage and current also increase further, indicating that the frequency stability of the device is good. Figure 6 (f) is the load power test diagram under contact separation mode. When the generator is connected in series with a 1GΩ resistor, the highest voltage at this time can be obtained through the output current. The highest voltage under non-ultrasonic excitation and ultrasonic excitation conditions reaches 775V and 1690V respectively.

[0048] Figure 7 The resistance output mechanism and signal characteristics of the generator are shown, where the time-resistance curve is as follows Figure 7As shown in (b), the horizontal axis is time / second (s) and the left vertical axis is resistance / ohm (Ω). Figure 7 The left figure in (a) is a schematic diagram of the device resistance corresponding to the external motion friction layer triggering. Figure 7 The right figure in (a) is the corresponding current amplification signal. It can be seen from the figure that the resistance change range is 100~300GΩ under low pressure (f=0.1N), and the device electrodes are still in an open circuit state; when the pressure exceeds the threshold, such as f=1N, the resistance change range reaches 10^ 9 The magnitude of the friction charge is 1.3, indicating that the friction charge passes through the PTFE porous membrane interface and is collected by the top electrode to form a closed loop, and the time scale of the resistance change corresponds to the contact-separation time interval of the external moving friction layer. This feature fully demonstrates the unique output mechanism of the friction charge-ion charge division of labor of the generator, which is expected to be applied in the field of self-driven wearable flexible electronics.

[0049] In summary, the present invention utilizes the flexible porous dielectric layer 3 and the liquid metal embedded layer 2 on the lower surface of the flexible porous dielectric layer 3 to construct a solid-liquid-gas three-phase interface. The flexible porous dielectric layer 3 stores high-density friction charges, while the liquid metal side produces a higher double-layer charge density. Due to the elastic modulus matching of the multiphase interface and the built-in electric field driving force, when the device is triggered by an external mechanical force, the friction charge and ion charge are separated under the drive of the built-in electric field. In this way, a friction-ion charge division of labor and cooperation interface based on the flexible porous dielectric layer 3 / liquid metal embedded layer 2 is realized, and high-voltage, direct current output is achieved. The generator has the advantages of high output, good stability, simple structure, and low cost, and can realize effective mechanical energy-electrical energy conversion and utilization.

[0050] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A multiphase soft metal elastomer DC generator, characterized in that: The invention comprises a flexible porous dielectric layer, a liquid metal embedding layer, an electret packaging layer, a bottom electrode layer and a top electrode layer. The liquid metal embedding layer is obtained by printing liquid metal on the lower surface of the flexible porous dielectric layer, the bottom electrode layer is arranged on the lower surface of the liquid metal embedding layer, the top electrode layer is arranged on the upper surface of the flexible porous dielectric layer, and the electret packaging layer is fixed on the upper surface of the top electrode layer.

2. The multiphase soft metal elastomer DC generator according to claim 1, characterized in that: The liquid metal is a gallium-indium-tin system and one or more of the following metals: bismuth, gold, silver, copper, zinc and aluminum.

3. The multiphase soft metal elastomer DC generator according to claim 1, characterized in that: The material of the flexible porous dielectric layer is one or more of porous polytetrafluoroethylene and electrospun nanofiber.

4. The multiphase soft metal elastomer DC generator according to claim 3, characterized in that: The thickness of the liquid metal embedding layer is less than 10 microns.

5. The multiphase soft metal elastomer DC generator according to claim 1, characterized in that: The material of the electret packaging layer is one or more of polytetrafluoroethylene, polyvinylidene fluoride, perfluoroethylene propylene, and polydimethylsiloxane.

6. The multiphase soft metal elastomer DC generator according to claim 1, characterized in that: The bottom electrode layer and the top electrode layer are made of conductive silver cloth.

7. The multiphase soft metal elastomer DC generator according to claim 6, characterized in that: The area of ​​the top electrode layer is smaller than that of the electret encapsulation layer, and the electret encapsulation layer covers the top electrode layer and the flexible porous dielectric layer.

8. The multiphase soft metal elastomer DC generator according to claim 7, characterized in that: The top electrode layer is in a strip shape, and the length of the top electrode layer is the same as the length of the electret packaging layer.

9. The method for preparing a multiphase soft metal elastomer DC generator according to claim 1, characterized in that: The steps include: Step 1, preparing liquid metal of target proportion; Step 2: placing liquid metal on the flexible porous dielectric layer to form a liquid metal embedded layer; Step 3: a bottom electrode layer is arranged on the lower surface of the liquid metal embedding layer, a top electrode layer is arranged on the upper surface of the flexible porous dielectric layer, and an electret packaging layer is arranged on the surface of the top electrode layer to construct a multiphase soft metal elastomer DC generator.

10. The multiphase soft metal elastomer DC generator according to claim 9, characterized in that: In step 2, the liquid metal is doctored onto the flexible porous dielectric layer using a stainless steel rod.

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