JP7467966B2 - Electric field-driven functional element, solid refrigerant cycle, and actuator - Google Patents

Description

The disclosure in this specification relates to electric field-driven functional elements, solid refrigerant cycles, and actuators.

U.S. Patent No. 5,399,633 discloses an element that utilizes an elastic elastomeric response. U.S. Patent No. 5,399,633 discloses an electrostatically deforming element. These elements exhibit an electrocaloric effect. The contents of the prior art documents are incorporated by reference as explanations of the technical elements in this specification.

JP 2018-530728 A International Publication No. 2018/208680

The element disclosed in Patent Document 1 has a limited polarization density because it contains an elastomer. The element disclosed in Patent Document 2 has a limited polarization density because it is electrostatically deformable. In an electric field-driven functional element, the polarization density affects the magnitude of the function to be derived. In one exemplary aspect, when the function of the electric field-driven functional element is to provide a mechanical displacement, the polarization density affects the magnitude of the mechanical displacement. In another exemplary aspect, when the function of the electric field-driven functional element is to provide an electrocaloric effect, the polarization density affects the magnitude of the electrocaloric effect. In the above-mentioned aspects, or in other aspects not mentioned, further improvements are required in the electric field-driven functional element, the solid refrigerant cycle, and the actuator.

One disclosed objective is to provide electric field-driven functional elements, solid refrigerant cycles, and actuators with improved polarization density.

The electric field-driven functional element disclosed herein comprises a first material (15) having a first molecule providing a first dipole (Df) that points in the direction of an electric field acting between a pair of electrodes (12, 13), and a second material (16) having a second molecule that enhances the mobility of the first molecule and provides a second dipole (Dr) that points in the direction of the electric field , wherein the first material and/or the second material is a liquid crystal polymer .
The electric field-driven functional element disclosed herein comprises a first material (15) having a first molecule providing a first dipole (Df) that orients in the direction of an electric field acting between a pair of electrodes (12, 13), and a second material (16) having a second molecule that enhances the mobility of the first molecule and provides a second dipole (Dr) that orients in the direction of the electric field, the first material and the second material being ferroelectric and liquid crystal polymers, and exhibiting the first dipole and the second dipole by spontaneous polarization.
The electric field-driven functional element disclosed herein comprises a first material (15) having a first molecule providing a first dipole (Df) that points in the direction of an electric field acting between a pair of electrodes (12, 13), and a second material (16) having a second molecule that enhances the mobility of the first molecule and provides a second dipole (Dr) that points in the direction of the electric field, the second material being a liquid.
The electric field-driven functional element disclosed herein comprises a first material (15) having a first molecule providing a first dipole (Df) that orients in the direction of an electric field acting between a pair of electrodes (12, 13), and a second material (16) having a second molecule that enhances the mobility of the first molecule and provides a second dipole (Dr) that orients in the direction of the electric field, the aspect ratio of the second molecule being 6.0 or greater.

According to the disclosed electric field-driven functional element, the electric field-driven functional element includes a first material and a second material. The second material has a second molecule for increasing the mobility of the first molecule contained in the first material. Furthermore, the second molecule provides a second dipole that is oriented in the direction of the electric field. The first material provides a first dipole that is oriented in the direction of the electrode. Thus, the polarization density in the functional element is provided by both the first dipole and the second dipole. As a result, an electric field-driven functional element with improved polarization density is provided.

The solid refrigerant cycle disclosed herein comprises the above-mentioned electric field-driven functional element (10) and an output member that outputs the electrocaloric effect of the functional element.

The actuator disclosed herein comprises the above-mentioned electric field-driven functional element (10) and an output member that outputs the mechanical displacement of the functional element.

The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference characters in parentheses in this section are illustrative of the corresponding relationships with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become clearer with reference to the detailed description that follows and the accompanying drawings.

1 is a block diagram showing an electric field-driven functional element according to a first embodiment; FIG. 1 is a block diagram showing an electric field-driven functional element. FIG. 2 is a cross-sectional view showing a dipole in a functional material. FIG. 2 is a cross-sectional view showing a dipole in a functional material. 2 is a graph showing the electric field E and the polarization P. 1 is a table listing examples of a first material. 1 is a table listing examples of a second material. 11 is a characteristic table showing a sample of a second material. FIG. 2 is a circuit diagram showing a measuring device. 1 is a graph showing the aspect ratio AR and the coercive voltage CV. FIG. 13 is a block diagram showing an electric field-driven functional element according to a second embodiment. FIG. 1 is a block diagram showing an electric field-driven functional element.

Several embodiments will be described with reference to the drawings. In several embodiments, functionally and/or structurally corresponding and/or associated parts may be given the same reference numerals or reference numerals that differ in the hundredth or higher digit. For corresponding and/or associated parts, the descriptions of other embodiments may be referred to.

First embodiment In Fig. 1 and Fig. 2, a solid refrigerant cycle 1 is illustrated. The solid refrigerant cycle 1 transfers heat from a low temperature member 2 to a high temperature member 3. The term solid refrigerant is used in contrast to a refrigerant in a vapor compression refrigerant cycle. The term solid refrigerant does not necessarily mean that a functional material 11 described below is solid. In fact, the functional material 11 described below is at least flowable and has the property of behaving like a liquid.

The solid refrigerant cycle 1 adjusts the temperature of an object. The object is a gas, liquid, or solid. When the solid refrigerant cycle 1 is a cycle that utilizes low temperature, the solid refrigerant cycle 1 cools the object by the low temperature member 2. In this case, the solid refrigerant cycle 1 provides a cycle for cooling, refrigeration, or freezing. When the solid refrigerant cycle 1 is a cycle that utilizes high temperature, the solid refrigerant cycle 1 heats the object by the high temperature member 3. In this case, the solid refrigerant cycle 1 provides a cycle for heating, warming, or heating. When the solid refrigerant cycle 1 is a cycle that utilizes both low temperature and high temperature, the solid refrigerant cycle 1 cools the object by the low temperature member 2 and heats the object by the high temperature member 3. In this case, the solid refrigerant cycle 1 provides a cycle for dehumidification, for example. The low temperature member 2 is also a heat absorption member or a heat source member in the solid refrigerant cycle 1. The high temperature member 3 is also a heat dissipation member or a heat supply member in the solid refrigerant cycle 1. In this specification, the term refrigeration cycle should be interpreted as including both refrigeration cycles that utilize low temperatures and heat pump cycles that utilize high temperatures.

The solid refrigerant cycle 1 includes an electric field-driven functional element 10. The functional element 10 provides an electrocaloric effect (ECE) as a function to be provided. The solid refrigerant cycle 1 utilizes only the high temperature, only the low temperature, or both the high temperature and the low temperature obtained by the electrocaloric effect exerted by the functional element 10. The functional element 10 exerts both heat absorption and heat dissipation functions by the electrocaloric effect. The functional element 10 generates heat transfer from the low temperature member 2 to the high temperature member 3 by the electrocaloric effect. The functional element 10 generates heat transfer by the electrocaloric effect so that the temperature of the high temperature member 3 is higher than the temperature of the low temperature member 2. The functional element 10 includes a functional material 11. The functional element 10 includes a pair of electrodes 12 and 13.

The functional material 11 is mostly made of organic material. The functional material 11 is made of a resin material. The functional material 11 may contain an inorganic material. The functional material 11 may include, for example, an inorganic filler.

The functional material 11 is made of a material that exhibits an electrocaloric effect in response to a change in an electric field applied to the electrodes 12 and 13. The functional material 11 is made of a material that changes its thickness in the thickness direction THD in response to a change in an electric field applied to the electrodes 12 and 13. The change in thickness in the thickness direction THD may be generated by an electrostatic force between the electrodes 12 and 13. The change in thickness in the thickness direction THD may be generated by an electrostrictive force. Thus, the functional element 10 in this embodiment provides both an electrocaloric effect and a mechanical displacement as functions.

The functional material 11 is provided as a polymer film. The polymer film can be provided by a normal film manufacturing method. The functional material 11 may have a container. The container contains the functional material 11. The container contributes to maintaining the thickness in the thickness direction THD. The functional material 11 may not have a container. In this case, the functional material 11 itself maintains its thickness.

The functional material 11 generates heat when an electric field is applied, and absorbs heat when the electric field is removed. When an electric field exceeding a predetermined value is applied to the functional material 11, the arrangement of electric dipoles provided by the molecules is aligned. At this time, the entropy of the functional material 11 decreases, and the functional material 11 releases heat. As a result, the temperature of the functional material 11 increases. When the electric field is removed, the arrangement of dipoles of the functional material 11 returns to a random state. At this time, the entropy of the functional material 11 increases, and the functional material 11 absorbs heat and the entropy increases when an electric field is removed from a state in which the functional material 11 has a small entropy due to the application of an external electric field. When an electric field is applied to the functional material 11 from a state in which the entropy is large, the functional material 11 releases heat and the entropy decreases.

The functional material 11 is disposed between the electrodes 12 and 13. The electrodes 12 and 13 can apply an electric field to the functional material 11 by a voltage supplied from the electric field modulation circuit 20. The electric field modulation circuit 20 modulates the strength of the electric field acting between the pair of electrodes 12 and 13 from strong to weak. The electric field modulation circuit 20 modulates the strength of the electric field between 0 (zero) and a maximum value. The electrodes 12 and 13 are disposed on both sides of the functional material 11 in the thickness direction THD. The electrodes 12 and 13 extend in a planar shape along the perpendicular direction PPD perpendicular to the thickness direction THD. The electrodes 12 and 13 are in contact with both sides of the functional material 11. The electrodes 12 and 13 may be in direct contact with the functional material 11. The electrodes 12 and 13 may be in indirect contact with the functional material 11 via a container.

The functional material 11 is switchable between a high heat transfer state and a low heat transfer state for only the low temperature member 2, only the high temperature member 3, or both the low temperature member 2 and the high temperature member 3. The high heat transfer state provides a predetermined high heat transfer rate. The low heat transfer state provides a lower heat transfer rate than the high heat transfer state. In the illustrated example, the functional material 11 transfers heat to the low temperature member 2 or the high temperature member 3 indirectly via the electrodes 12, 13. Alternatively, the functional material 11 may transfer heat to the low temperature member 2 or the high temperature member 3 directly without via the electrodes 12, 13. The illustrated functional material 11 provides heat transfer in the thickness direction THD. Alternatively, the functional material 11 may provide heat transfer in the orthogonal direction PPD.

In this respect, a thermal switch is provided between the functional material 11 and the low-temperature member 2, or between the functional material 11 and the high-temperature member 3. The thermal switch provides a high heat transfer state and a low heat transfer state. The thermal switch switches the heat transfer state in synchronization with the thermal action in the functional element 10. In this embodiment, the thermal switch switches the heat transfer state in synchronization with the electric field modulation acting on the functional material 11. The thermal switch provides a high heat transfer state between the low-temperature member 2 and the functional element 10 when the functional element 10 absorbs heat. The thermal switch provides a high heat transfer state between the high-temperature member 3 and the functional element 10 when the functional element 10 generates heat. It is preferable that the thermal switch provides a low heat transfer state between the low-temperature member 2 and the functional element 10 when the functional element 10 generates heat. It is preferable that the thermal switch provides a low heat transfer state between the high-temperature member 3 and the functional element 10 when the functional element 10 absorbs heat. In this embodiment, the thermal switch is provided by the displacement of the functional element 10 described below. The thermal switch may be achieved by switching the flow state of the fluid components in the low temperature member 2 or the high temperature member 3.

The electrodes 12 and 13 are disposed on both sides of the functional material 11. In this respect, the electrodes 12 and 13 are also called end electrodes. As end electrodes, the electrodes 12 and 13 apply an electric field to the functional material 11 over the entire length of the functional material 11 in the thickness direction THD.

The electrode 12 is switchable between a high heat transfer state and a low heat transfer state with respect to the low temperature member 2. In the illustrated example, the switching between the two states is provided by a change in thickness of the functional material 11. The high heat transfer state is a contact state in which the electrode 12 and the low temperature member 2 are in contact. The low heat transfer state is a non-contact state in which the electrode 12 and the low temperature member 2 are separated. The electrode 12 is movable so as to switchably provide a contact state and a non-contact state with respect to the low temperature member 2. The contact state and the non-contact state define the direction of heat transfer. In this respect, the electrode 12 is a movable electrode.

The electrode 13 is placed in contact with the high-temperature member 3. In this respect, the electrode 13 is a fixed electrode. The electrode 13 is continuously in a high heat transfer state with respect to the high-temperature member 3. Alternatively, the electrode 13 may be configured to be switchable between a high heat transfer state and a low heat transfer state with respect to the high-temperature member 3.

The solid refrigerant cycle 1 includes an electric field modulation circuit 20. The electric field modulation circuit 20 supplies a voltage to the electrodes 12, 13. The electric field modulation circuit 20 applies an electric field between the pair of electrodes 12, 13. In other words, the electric field modulation circuit 20 applies an electric field to the functional material 11 located between the pair of electrodes 12, 13. Furthermore, the electric field modulation circuit 20 modulates the strength of the electric field from strong to weak. The electric field modulation circuit 20 modulates the strength of the electric field between 0 (zero) and the maximum value that can be supplied.

The electric field modulation circuit 20 includes a circuit member 21 that supplies a voltage to the electrodes 12 and 13. The circuit member 21 is provided by an electric wire, a conductive film, a bus bar, or the like. The electric field modulation circuit 20 includes a DC power source 22 that supplies a DC voltage. The electric field modulation circuit 20 includes a switch element 23 for turning on and off the voltage supply to the electrodes 12 and 13. The switch element 23 can also be called a switch device. The switch element 23 can be switched between an on state and an off state. The switch element 23 is an element that can be controlled by a control device 24. The electric field modulation circuit 20 includes a control device 24 (ECU). The control device 24 controls the switch element 23. The control device 24 alternately switches the switch element 23 between an on state and an off state so that the functional element 10 performs its function. When the control device 24 controls the switch element 23 to an off state, the functional element 10 is controlled to an inactive state. When the control device 24 controls the switch element 23 to an on state, the functional element 10 is controlled to an active state.

The control device in this specification may also be referred to as an electronic control unit (ECU). The control device or control system is provided by (a) an algorithm as multiple logics called if-then-else format, or (b) an algorithm as a trained model tuned by machine learning, for example a neural network. The control device is provided by a control system including at least one computer. The control system may include multiple computers linked by a data communication device. The computer includes at least one processor that is hardware (a hardware processor). The hardware processor may be provided by the following (i), (ii), or (iii).

(i) The hardware processor may be at least one processor core that executes a program stored in at least one memory. In this case, the computer is provided with at least one memory and at least one processor core. The processor core is called a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a RISC-CPU, etc. The memory is also called a storage medium. The memory is a non-transitive and tangible storage medium that non-temporarily stores "programs and/or data" that can be read by the processor. The storage medium is provided by a semiconductor memory, a magnetic disk, an optical disk, etc. The program may be distributed alone or as a storage medium on which the program is stored.

(ii) The hardware processor may be a hardware logic circuit. In this case, the computer is provided by a digital circuit including a large number of programmed logic units (gate circuits). The digital circuit is also called a logic circuit array, for example, ASIC: Application-Specific Integrated Circuit, FPGA: Field Programmable Gate Array, SoC: System on a Chip, PGA: Programmable Gate Array, CPLD: Complex Programmable Logic Device, etc. The digital circuit may include a memory that stores programs and/or data. The computer may be provided by an analog circuit. The computer may be provided by a combination of digital and analog circuits.

(iii) The hardware processor may be a combination of (i) and (ii) above. (i) and (ii) may be located on different chips or on a common chip. In these cases, part (ii) is also called an accelerator.

Figure 1 shows the inactive state of the functional element 10. In the inactive state, no electric field acts on the functional material 11 between the pair of electrodes 12, 13. The inactive state is also called the non-excited state. In the inactive state, the functional material 11 is in the inactive shape DS. In the inactive shape DS, the functional material 11 has a thickness t1. In the inactive shape DS, the functional material 11 absorbs heat from the low temperature member 2. In the inactive shape DS, the functional material 11 also absorbs heat from the high temperature member 3.

Figure 2 shows the active state of the functional element 10. In the active state, an electric field acts on the functional material 11 between the pair of electrodes 12, 13. The active state is also called an excited state. In the active state, the functional material 11 is in the active shape AS. In the active shape AS, the functional material 11 has a thickness t2. In the active shape AS, the functional material 11 dissipates heat to the high temperature member 3. In the active shape AS, the functional material 11 is in a low heat transfer state with the low temperature member 2. Therefore, in the active shape AS, the functional material 11 hardly dissipates heat to the low temperature member 2.

When the solid refrigerant cycle 1 is in operation, the control device 24 controls the switch element 23 to alternate between the state shown in FIG. 1 and the state shown in FIG. 2. As a result, the functional element 10 provides heat transfer from the low temperature member 2 to the high temperature member 3. The solid refrigerant cycle 1 utilizes the low temperature appearing in the low temperature member 2 and/or the high temperature appearing in the high temperature member 3.

Figures 3 and 4 show models of molecules contained in the functional material 11. The functional material 11 is a polymeric material. The functional material 11 as a whole has properties similar to liquid crystals in which polymer chains are arranged. The functional material 11 is also called a liquid crystal polymer. The functional material 11 is at least capable of flowing. The functional material 11 exhibits the properties of a liquid. The functional material 11 includes first molecules of a first material 15 and second molecules of a second material 16.

The functional material 11 includes a first material 15. The first material 15 is a polymer material. The first material 15 is a material that exhibits the function to be provided by the functional element 10, which in this embodiment is an electrocaloric effect. The first material 15 is also called the main material in the functional material 11. The first material 15 has properties similar to those of a liquid crystal in which polymer chains are arranged. The first material 15 is also called a liquid crystal polymer.

The functional material 11 includes a second material 16. The second material 16 is a polymer material. The second material 16 is a material that does not form polymer chains with the first material 15. The second material 16 is also called an additive in the functional material 11. The second material 16 has properties similar to liquid crystals in which polymer chains are aligned. The second material 16 is also called a liquid crystal polymer.

The second material 16 is a material that increases the plasticity of the first material 15. In this respect, the second material 16 is also called a plasticizer or relaxer in the functional material 11. The second material 16 is added as a plasticizing component to the first material 15. The presence of the second material 16 gives fluidity to the functional material 11. The presence of the second material 16 causes the functional material 11 to exhibit gel properties. The second material 16 is also called a gelling agent. The presence of the second material 16 gives the functional material 11 fluid properties.

The second material 16 is a liquid component. The second material 16 is liquid in the operating temperature range of the functional material 11. The operating temperature range is defined based on the maximum and minimum temperatures in the operating state of the functional material 11. The second material 16 may occupy a range of 0.1% by weight or more and 600% by weight or less of the functional material 11. The second material 16 may be mainly composed of a polymer and may also contain an inorganic filler. The inorganic filler is dispersedly disposed in the second material 16.

Figures 3 and 4 show electric dipoles as models using arrow symbols. The functional material 11 has dielectric properties. The first material 15 has dielectric properties. The second material 16 has dielectric properties. The first material 15 and the second material 16 constituting the functional material 11 are ferroelectrics in which dipoles appear due to spontaneous polarization. The first molecule of the first material 15 has a first dipole Df with a predetermined dipole moment. The second molecule of the second material 16 has a second dipole Dr with a predetermined dipole moment.

The first material 15 and the second material 16 may both be paraelectrics that do not have spontaneous polarization. Alternatively, one of the first material 15 and the second material 16 may be a paraelectric and the other a ferroelectric. When the first material 15 is a paraelectric, the first material 15 undergoes dielectric polarization in an electric field and exhibits a dipole that is oriented in the direction of the electric field (thickness direction THD). When the second material 16 is a paraelectric, the second material 16 undergoes dielectric polarization in an electric field and exhibits a dipole that is oriented in the direction of the electric field (thickness direction THD). In a preferred embodiment, at least one of the first material 15 and the second material 16 is a ferroelectric.

The functional material 11 has both the properties of a ferroelectric and the properties of a liquid crystal polymer. The first material 15 has both the properties of a ferroelectric and the properties of a liquid crystal polymer. The second material 16 has both the properties of a ferroelectric and the properties of a liquid crystal polymer. From these perspectives, the first material 15 and the second material 16 are called ferroelectric liquid crystal polymers.

Figure 3 shows multiple dipoles in an inactive state. In an inactive state, both the first dipole Df and the second dipole Dr are randomly oriented. Functional material 11 that exhibits liquid properties tends to have a random molecular arrangement.

Figure 4 shows multiple dipoles in an active state. In the active state, both the first dipole Df and the second dipole Dr are oriented in the direction of the electric field (thickness direction THD) by the electric field acting between the pair of electrodes 12, 13. In other words, the functional material 11 has a first dipole Df and a second dipole Dr that are oriented along the direction of the electric field (thickness direction THD) by the electric field acting between the pair of electrodes 12, 13. The functional material 11, which exhibits liquid properties, is prone to have its molecular arrangement oriented in a predetermined direction by the action of an external electric field.

The second material 16, due to its properties as a plasticizer, provides gaps between the polymer chains of the first material 15. In other words, the presence of the second material 16 provides more gaps between the multiple first dipoles Df than the base material of only the first material 15 without the second material 16. As a result, the second material 16 increases the mobility of the first molecules of the first material 15, i.e., the first dipoles Df. The second material 16 acts to make the first dipoles Df easier to move. The second material 16 improves the polarization P in the functional material 11 by increasing the mobility of the first dipoles Df.

Furthermore, the second molecule of the second material 16 itself has a second dipole Dr with a predetermined dipole moment. The second dipole Dr increases the polarization density in the functional material 11 and improves the polarization P in the functional material 11.

Figure 5 shows hysteresis curves of the electric field E and polarization P. The dashed line CMP1 is a hysteresis curve of a comparative example including only the first material 15. The dashed line CMP2 is a hysteresis curve of a comparative example showing the action of the second material 16 as a plasticizer. The solid line EMB is a hysteresis curve of the functional material 11. The second material 16 reduces the coercive voltage in the functional material 11 due to its properties as a plasticizer or relaxor. Furthermore, the second material 16 itself has a second dipole Dr, thereby increasing the polarization density in the functional material 11. In other words, the polarization P in the functional material 11 is increased by an increment Id due to the second dipole Dr.

The low coercive voltage allows the dipole moment in the functional material 11 to be isotropic. As a result, a high entropy change amount ΔS can be realized, and therefore a high electrocaloric effect (cooling capacity) can be realized. Furthermore, since the polarization P in the same electric field becomes high, the thickness of the functional material 11 can be relatively large. By increasing the thickness of the functional material 11, the temperature difference ΔT between the low temperature end and the high temperature end can be increased. As a result, high efficiency as the solid refrigerant cycle 1 can be realized. Efficiency can be evaluated, for example, by the coefficient of performance (COP).

Figure 6 shows examples I-VII of the first material 15. The first material 15 can include any one of the materials I-VII shown in Figure 6. The first material 15 can also be a copolymer or a mixture of the materials I-VII. In the main embodiment, the first material 15 is provided by a PVdF-based resin (polyvinylidene fluoride resin). Alternatively, the first material 15 can include any one of the materials II-VII shown in Figure 6. The first material 15 can be provided by, for example, PVdF-TrFE or PVdF-TrFE-CFE, which includes polyvinylidene fluoride PVdF and trifluoroethylene (TrFE) and/or 1-chloro-1-fluoro-ethylene (CFE) as additives.

Figure 7 shows examples 1-12 of the second material 16. The second material 16 can include any one of the materials 1-12 shown in Figure 7. The number of alkyl chains in the second material 16 is 2-12. The second material 16 may be a mixture of examples 1-12. The second material 16 has a functional group that interacts strongly with the first material 15 and a functional group that interacts weakly with the first material 15.

Figure 8 shows samples S1, S2, and S3 of the second material 16 in the embodiment. In Figure 8, the molecular structure MOL, boiling point Tb, aspect ratio AR, dipole moment DM, and dielectric constant ε (epsilon) of the second material 16 are shown. The aspect ratio AR is the long side/short side of the polymer chain that provides the second material 16. Sample S1 is a phthalate ester. Sample S2 is an adipic acid-based polyester. Sample S3 is a cyclic carbonate ester. Samples S1, S2, and S3 are also called ester-based additives.

In the embodiment, the manufacturing method of the functional material 11 includes a mixing step of mixing the first material 15 and the second material 16. The first material 15 is PVdF-TrFE. The second material 16 is sample S1, S2, or S3 shown in FIG. 8. The manufacturing method of the functional material 11 includes a film forming step of forming the functional material 11 into a film. The film forming step can be provided by a spin coating method. Furthermore, the manufacturing method of the functional material 11 includes an annealing step of annealing the film manufactured in the film forming step. The annealing step is provided by placing the film in an atmosphere at 120° C. for 30 min. The manufacturing method of the functional material 11 includes a polarization step after the annealing step. The polarization step is also called a poling step. The poling step is provided by placing the film in an electric field of 100 V/μm and 0.05 Hz.

Figure 9 shows a measuring device 50 for measuring electric field-polarization characteristics. In the embodiment, the electric field-polarization characteristics of the functional material 11 sample are measured by the Sawyer Tower circuit shown in the figure. In the measuring device 50, a function generator 51 and an amplifier 52 provide an AC voltage for measurement. The sample 53 is placed between electrodes 54 and 55. The electrodes 54 and 55 are provided by aluminum films with an average thickness of 100 nm. The sample 53 is placed in series with a reference capacitance element 56. In this embodiment, the reference capacitance element 56 is 1 μF. The AC voltage is applied to the series circuit of the sample 53 and the reference capacitance element 56. The electric field-polarization characteristics are measured by observing the waveform that appears on an oscilloscope 57.

Figure 10 shows the aspect ratios AR of samples S1, S2, and S3 and the coercive voltages CV of the samples. The coercive voltage of sample S0 using only PVdF-TrFE as the first material 15 is shown by a circle. The coercive voltage Vt of only PVdF-TrFE-CFE available as the first material 15 is shown by a dashed line. PVdF-TrFE-CFE shows a relatively desirable hysteresis curve. From this, the coercive voltage Vt can be used as a target coercive voltage to be realized by the available functional material 11. The coercive voltage of sample S0+S1 using sample S1 as the second material 16 is shown by a triangle. The coercive voltage of sample S0+S2 using sample S2 as the second material 16 is shown by a double circle. The coercive voltage of sample S0+S3 using sample S3 as the second material 16 is shown by a square. Sample S3 has a relatively large aspect ratio AR=7.8.

As described above, the second material 16 enhances the mobility of the polymer chains of the first material 15. In a typical example, the mobility of the polymer chains of the first material 15 is evaluated by rotation. Furthermore, as described above, the second material 16 enhances the polarization density in the functional material 11 by its second dipole Dr. In addition, as shown in FIG. 10, it is considered that the larger the aspect ratio AR of the second material 16, the more it assists the movement of the polymer chains of the first material 15.

Based on multiple samples S0, S1, S2, and S3, an assumed line LN can be assumed that shows the relationship between the aspect ratio AR and the coercive voltage CV. Based on this assumed line LN, in order to satisfy the target coercive voltage Vt, it is desirable that the aspect ratio AR of the second material 16 is 6.0 or more. By setting the aspect ratio AR of the second molecule of the second material 16 to 6.0 or more, a low coercive voltage can be achieved. A low coercive voltage makes it possible to suppress hysteresis.

According to the embodiment described above, an electric field-driven functional element is provided in which the polarization density of the functional material 11 is improved by the second material 16. This improvement is brought about by the improvement in the mobility (mobility) of the first material 15 by the second material 16 and the improvement in the polarization density by the second dipole Dr of the second material 16 itself.

Second Embodiment This embodiment is a modification of the preceding embodiment as a basic form. In the above embodiment, the electric field-driven functional element 10 provides a solid refrigerant cycle 1. The functional element 10 functions as a solid refrigerant that generates heat transfer by the fluctuation of an electric field. Instead, in this embodiment, the electric field-driven functional element 10 provides an actuator 201. The functional element 10 functions as a power source that outputs a mechanical displacement by the fluctuation of an electric field.

In FIG. 11 and FIG. 12, the functional element 10 provides an actuator 201. The actuator 201 outputs a displacement La of the functional element 10 by modulation of an electric field as external energy. The actuator 201 includes an end piece 202 and an end piece 203. The end piece 202 is mechanically connected to the electrode 13. The end piece 203 is mechanically connected to the electrode 12. The end piece 202 is also called a movable piece. The end piece 202 provides an output member for outputting a mechanical displacement La. The end piece 203 is fixed to a member that defines a reference for the displacement. The end piece 203 is also called a fixed piece.

In this embodiment, the end piece 202 outputs the mechanical displacement La exclusively. Alternatively, the end piece 202 may be a fixed piece, and the end piece 203 may be a movable piece. In this case, the end piece 203 provides the output member. Also, both the end piece 202 and the end piece 203 may be movable pieces. In this case, both the end piece 202 and the end piece 203 provide the output member. The functional element 10 can directly output the deformation of the functional material 11. The functional element 10 can quietly output the mechanical displacement. The actuator 201 can be used, for example, as an artificial muscle.

According to this embodiment, it is possible to provide an electric field-driven functional element, i.e., an actuator, in which the overall polarization density of the functional material 11 is improved. According to this embodiment, for example, it is possible to achieve an increase in the amount of displacement that can be extracted, an increase in the displacement force that can be extracted, or both an increase in the amount of displacement and an increase in the displacement force.

Other embodiments The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and/or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and/or elements of the embodiments. The disclosure includes the substitution or combination of parts and/or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

The disclosure in the specification and drawings, etc. is not limited by the claims. The disclosure in the specification and drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and extensive technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification and drawings, etc., without being bound by the claims.

In the above embodiment, the functional element 10 is a single stage. Alternatively, the functional elements 10 may be arranged in series to provide a series multistage element. Alternatively, the functional elements 10 may be arranged in parallel to provide a parallel multistage element. Furthermore, the functional elements 10 may be arranged in series and in parallel to provide a series-parallel multistage element.

1 Solid refrigerant cycle, 2 Low temperature member, 3 High temperature member,
10 functional element, 11 functional material, 12, 13 electrode,
15 First material, 16 Second material, 20 Electric field modulation circuit,
21 Circuit member, 22 DC power source, 23 Switch element,
24 control device (ECU), 50 measuring device,
51 function generator, 52 amplifier,
53 sample, 54, 55 electrodes, 57 oscilloscope,
AS active shape, DS non-active shape, t1, t2 thickness,
Df first dipole, Dr second dipole,
201 actuator.

Claims (13)

a first material (15) having first molecules providing a first dipole (Df) that is oriented in the direction of an electric field acting between a pair of electrodes (12, 13);
a second material (16) having second molecules that enhance the mobility of the first molecules, the second molecules providing a second dipole (D) oriented in the direction of the electric field ;
The electric field-driven functional element , wherein the first material and/or the second material is a liquid crystal polymer . 2. The electric field-driven functional element according to claim 1 , wherein the first material and/or the second material is a ferroelectric material. a first material (15) having first molecules providing a first dipole (Df) that is oriented in the direction of an electric field acting between a pair of electrodes (12, 13);
a second material (16) having second molecules that enhance the mobility of the first molecules, the second molecules providing a second dipole (D) oriented in the direction of the electric field ;
The first material and the second material are ferroelectric and liquid crystal polymer, and the electric field-driven functional element exhibits the first dipole and the second dipole by spontaneous polarization . The electric field-driven functional element according to claim 1 , wherein the second material is a liquid. a first material (15) having first molecules providing a first dipole (Df) that is oriented in the direction of an electric field acting between a pair of electrodes (12, 13);
a second material (16) having second molecules that enhance the mobility of the first molecules, the second molecules providing a second dipole (D) oriented in the direction of the electric field ;
The second material is a liquid . The electric field-driven functional element according to claim 5 , wherein the first material and/or the second material is a ferroelectric material. The electric field-driven functional element according to any one of claims 1 to 6, wherein the aspect ratio of the second molecule is 6.0 or more. a first material (15) having first molecules providing a first dipole (Df) that is oriented in the direction of an electric field acting between a pair of electrodes (12, 13);
a second material (16) having second molecules that enhance the mobility of the first molecules, the second molecules providing a second dipole (D) oriented in the direction of the electric field ;
An electric field-driven functional element , wherein the aspect ratio of the second molecule is 6.0 or more . The electric field-driven functional element according to claim 8 , wherein the first material and/or the second material is a ferroelectric material. 10. The electric field-driven functional element according to claim 1 , further comprising an electric field modulation circuit (20) for modulating the electric field. 11. The electric field-driven functional element according to claim 1, wherein the second material is added as a plasticizing component to the first material. An electric field-driven functional element (10) according to any one of claims 1 to 11 ,
and an output member that outputs the electrocaloric effect of the functional element. An electric field-driven functional element (10) according to any one of claims 1 to 11 ,
and an output member that outputs a mechanical displacement of the functional element.

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