Dual-Trip Shape Memory Hinge Device Based on Semiconductor Temperature Control and Its Usage Method

Abstract

The present invention provides a two-way shape memory hinge device based on semiconductor temperature control. In the extension assembly, it includes a temperature-controlled semiconductor layer, a shape memory alloy layer, and a shape memory polymer layer, and the temperature-controlled semiconductor layer is located between the shape memory alloy layer and the shape memory polymer layer. The temperature-controlled semiconductor layer includes refrigerating semiconductor grains, a flexible heat insulation material, copper sheets, and a flexible heat conduction material. The refrigerating semiconductor grains exist in pairs, and a flexible heat insulation material is provided between adjacent refrigerating semiconductor grains. The copper sheets located at both ends of the refrigerating semiconductor grains are respectively connected to the bonding surfaces of the shape memory alloy layer and the shape memory polymer layer through the flexible heat conduction material. The present invention controls the temperature of the shape memory alloy layer or the shape memory polymer layer by changing the current direction of the refrigerating semiconductor grains, realizes the repeated and controllable deformation of the extension assembly, is easy to realize the self-locking and self-unfolding functions, and has the advantages of small unfolding impact and large stiffness.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and particularly relates to a two-way shape memory hinge device based on semiconductor temperature control and a method for using the same. Background Art

[0002] With the development of the aerospace industry, space folding and unfolding mechanisms are gradually tending towards lightweight, large-scale, and intelligent. By designing components such as solar panels and antennas as foldable devices, the envelope volume can be greatly reduced and the space utilization rate can be improved. Traditional folding and unfolding mechanisms in the aerospace field rely on mechanical structure drive. The driving methods of mechanical structure drive joint hinges mainly include: spring hinges, motors, motor-spring hybrids, and high-elasticity materials, etc., which have the disadvantages of large occupied space, large mass, and large deployment impact.

[0003] The hinge structure with shape memory function solves the defects of mechanical structure drive to a certain extent. Shape memory alloy (SMA) has the characteristics that after loading and unloading at low temperature, residual strain appears, and at high temperature (>Af), the residual strain can be eliminated and the original shape can be restored. Thermoplastic shape memory polymer (SMP) is in a high-strength glassy state below the phase transition temperature t g The following is a high-strength glassy state, and above the phase transition temperature t g It turns into a highly elastic rubber state. Self-driving hinge structures made of shape memory alloys and shape memory polymers have been applied in the aerospace field. For example, in a patent for a shape memory hinge unfolding structure, the stretching device is made of pod-shaped rod-shaped shape memory polymer and is heated and unfolded by a heating film; in a patent for an aerospace temperature-controlled louver mechanism based on shape memory polymer drive, a shape memory polymer spring is used to achieve reciprocating motion; in the paper "Analysis and Simulation of a Micro Thermal Control Louver Driver", a micro thermal control louver driver is proposed. This driver uses thermoelectric refrigeration as the temperature control device and a metal with a high coefficient of thermal expansion as the moving part to realize the opening and closing of the thermal control louver.

[0004] Semiconductor refrigeration uses a P-N junction composed of special semiconductor materials to form a thermocouple pair, and realizes active and controllable heat flow transfer through current. For example, in the utility model patent with the application number CN202221093197.4, flexible heat-conducting films are provided on the outer sides of multiple heat-conducting sheets and multiple cold-conducting sheets, so that the semiconductor refrigeration sheet has good bending performance and can fit various terminal curved surfaces to ensure the refrigeration effect.

[0005] The following deficiencies exist in the above-mentioned patents or papers: For a one-way shape memory hinge, after being heated by a heating film to restore its initial shape, it cannot be folded and unfolded repeatedly; since the two-way shape memory material responds in real time to excitation, for a two-way shape memory deployment structure, the stimulation conditions of the shape memory material need to be maintained. Therefore, maintaining the shape requires consuming a large amount of energy or relying only on external environmental stimuli, and active control with low energy consumption cannot be achieved. Therefore, the present invention proposes a two-way shape memory hinge device based on semiconductor temperature control. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the present invention provides a two-way shape memory hinge device based on semiconductor temperature control and its usage method. By adopting a multi-layer composite structure of "shape memory alloy layer + temperature control semiconductor layer + shape memory polymer layer", alternating current or direct current is respectively applied to the refrigerating semiconductor grains in the temperature control semiconductor layer, and the characteristics of the shape memory material are utilized to enable the hinge device to repeatedly switch between the retracted state and the deployed state and between the self-locking deployed state and the self-locking retracted state, so as to achieve a stable and controllable two-way shape memory function without the need for continuous energy supply and maintaining the stimulation conditions of the shape memory material, greatly reducing the energy consumption of the two-way shape memory folding and unfolding structure of the spacecraft, and improving the utilization efficiency of the internal and external space of the spacecraft and the survivability of the folding and unfolding mechanism in space.

[0007] The present invention provides a two-way shape memory hinge device based on semiconductor temperature control, which includes an extension component and a fixture. The extension component is of a flat plate type, and fixtures are symmetrically arranged on both sides of the extension component. The extension component includes a temperature control semiconductor layer and a shape memory material layer. The shape memory material layer includes a shape memory alloy layer and a shape memory polymer layer. The temperature control semiconductor layer is located between the shape memory alloy layer and the shape memory polymer layer. The temperature control semiconductor layer realizes the active control of the heat flow in the extension component, enabling the shape memory alloy and the shape memory polymer to alternately exhibit the shape memory effect. The temperature control semiconductor layer includes refrigerating semiconductor grains, a flexible heat insulation material, copper sheets, and a flexible heat conduction material. The refrigerating semiconductor grains exist in pairs, and the flexible heat insulation material is arranged between adjacent refrigerating semiconductor grains. The copper sheets located at both ends of the refrigerating semiconductor grains are respectively connected to the bonding surfaces of the shape memory alloy layer and the shape memory polymer layer through the flexible heat conduction material. The refrigerating semiconductor grains are distributed along the bending direction of the extension component at a pitch of 1.3 mm to 6.2 mm, and the refrigerating semiconductor grains are distributed in the direction perpendicular to the bending direction of the extension component at a pitch of 1 mm to 4 mm, so as to ensure the filling rate of the refrigerating semiconductor grains and the refrigerating and heating power. The bending neutral plane of the extension component is located inside the temperature control semiconductor layer. The strain expression of the shape memory alloy layer in the extension component is:

[0008]

[0009] Among them, ρ(t) is the bending radius of the bending neutral plane of the stretching component, a is the thickness of the shape memory alloy layer, and b 1 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory alloy layer;

[0010] The strain expression of the shape memory polymer layer in the stretching component is:

[0011]

[0012] Among them, ρ(t) is the bending radius of the bending neutral plane of the stretching component, ρ is the bending radius during the manufacture of the stretching component, c is the thickness of the shape memory polymer layer, and b 1 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory alloy layer, and b 2 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory polymer layer.

[0013] The strain expression of the temperature control semiconductor layer in the stretching component is:

[0014]

[0015] Among them, ρ(t) is the bending radius of the bending neutral plane of the stretching component, ρ is the bending radius during the manufacture of the stretching component, and b 1 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory alloy layer, and b 2 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory polymer layer.

[0016] Preferably, when the stretching component is in the retracted state, the shape memory alloy layer has the maximum strain, and the specific expression is as follows:

[0017]

[0018] Among them, a is the thickness of the shape memory alloy layer, and b 1 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory alloy layer, and ρ 1 is the bending radius of the stretching component in the deployed state;

[0019] When the stretching component is in the deployed state, the temperature control semiconductor layer has the maximum strain, and the specific expression is as follows:

[0020]

[0021] Among them, b 2 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory polymer layer, and ρ 1where \(R\) is the bending radius of the extension component in the deployed state, and \(\rho_0\) is the bending radius during the manufacturing of the extension component;

[0022] When the extension component is in the deployed state, the shape memory polymer layer has the maximum strain, and the specific expression is as follows:

[0023]

[0024] where \(b\) 2 is the distance from the bending neutral plane of the extension component to the bonding surface of the shape memory polymer layer, \(c\) is the thickness of the shape memory polymer layer, \(R\) 1 is the bending radius of the extension component in the deployed state, and \(\rho_0\) is the bending radius during the manufacturing of the extension component.

[0025] Preferably, the bending radius \(R\) of the extension component in the deployed state 1 is 6 mm to 30 mm.

[0026] Preferably, the length of the refrigerating semiconductor grains is 0.7 to 0.9 times the thickness of the temperature control semiconductor layer, and the cross-section of the refrigerating semiconductor grains is a rectangle with a side length of 1 mm to 3 mm.

[0027] Preferably, the temperature control system connected to the temperature control semiconductor layer is a driving chip composed of field effect transistors forming an H-bridge.

[0028] Preferably, the total thickness \(d\) of the extension component is 3 - 15 mm.

[0029] Preferably, the shape memory alloy layer is any one or several of Au - Cd, Ag - Cd, Cu - Zn, Cu - Zn - Al, Cu - Zn - Sn, Cu - Zn - Si, Cu - Sn, Cu - Zn - Ga, In - Ti, Au - Cu - Zn, Ni - Al, Fe - Pt, Ti - Ni, Ti - Ni - Pd, Ti - Ni - Zr, Ti - Nb, U - Nb, or Fe - Mn - Si; the shape memory polymer layer is any one or several of epoxy - based or cyanate - based shape memory polymer resins; and the refrigerating semiconductor grains are any one or several of PbTe, ZnSb, SiGe, AgSbTe₂, Sb₂Te₃, Sb₂Se₃, Sb₂Te, Bi₂Te₃, SbI₃, Bi₂Se₃, or TeI₄.

[0030] On the other hand, the present invention provides a method for using the aforementioned dual - way shape memory hinge device based on semiconductor temperature control, which includes the following steps:

[0031] S1. When the two-way shape memory hinge device is in the initial folded state, apply alternating current to the refrigerating semiconductor grains in the temperature-controlled semiconductor layer, so that the shape memory alloy layer and the shape memory polymer layer located at both ends of the refrigerating semiconductor grains are heated until the temperatures of the shape memory alloy layer and the shape memory polymer layer are both higher than their respective phase transition temperatures. At this time, utilize the characteristics of the shape memory alloy and the shape memory polymer to change the two-way shape memory hinge device from the folded state to the unfolded state;

[0032] S2. When the two-way shape memory hinge device is in the unfolded state of step S1, apply direct current to the refrigerating semiconductor grains in the temperature-controlled semiconductor layer, so that the shape memory alloy layer located at the first end of the refrigerating semiconductor grains is heated. At this time, the temperature of the shape memory alloy layer is higher than its own phase transition temperature and remains in the unfolded state, and the shape memory polymer layer located at the second end of the refrigerating semiconductor grains is cooled. At this time, the temperature of the shape memory polymer layer is lower than its own phase transition temperature;

[0033] S3. On the basis of step S2, stop applying alternating current and direct current to the refrigerating semiconductor grains in the temperature-controlled semiconductor layer. At this time, in the external environment, the shape memory alloy layer and the shape memory polymer layer overcome the resistance of the temperature-controlled semiconductor layer, so that the two-way shape memory hinge device changes from the unfolded state to the folded state and maintains the unfolded state to achieve self-locking;

[0034] S4. When the two-way shape memory hinge device is in the self-locked state and is being folded, apply direct current in the direction opposite to that in step S2 to the refrigerating semiconductor grains in the temperature-controlled semiconductor layer, so that the shape memory polymer layer located at the second end of the refrigerating semiconductor grains is heated. At this time, the temperature of the shape memory polymer layer is higher than its own phase transition temperature, and the shape memory alloy layer located at the first end of the refrigerating semiconductor grains is cooled. At this time, the temperature of the shape memory alloy layer is lower than its own phase transition temperature. The shape memory polymer layer overcomes the resistance of the temperature-controlled semiconductor layer and the shape memory alloy layer, so that the two-way shape memory hinge device returns from the self-locked unfolded state to the folded state;

[0035] S5. When the two-way shape memory hinge device is in the folded state of step S4, stop applying alternating current and direct current to the refrigerating semiconductor grains in the temperature-controlled semiconductor layer. At this time, in the external environment, the shape memory polymer layer cools down to below its own phase transition temperature, so that the two-way shape memory hinge device maintains the folded state and achieves self-locking.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. Compared with the deployment of a mechanical transmission structure, the present invention does not require a motor structure for driving, has the characteristics of integration of driving and load-bearing, and can meet the functional requirements of modern spacecraft for small deployment impact, light weight, small occupied space, and self-locking of the deployment device.

[0038] 2. Compared with traditional shape memory hinges, the present invention adopts a multi-layer composite structure of "shape memory material layer + temperature control semiconductor layer + shape memory material layer". When using shape memory alloys and shape memory polymers simultaneously, the hinge can achieve complementary strength at low and high temperatures, maintain good strength during both the static state and the unfolding process of the hinge, improve the adaptability of the hinge to the harsh environment of sudden temperature changes in space, and ensure the reliability of the spacecraft during launch and hinge unfolding.

[0039] 3. In the present invention, the semiconductor refrigeration chip usually uses a ceramic chip for heat conduction, so it is a rigid component. And because ceramics are difficult to withstand drastic temperature changes, it is impossible to achieve heat exchange between the hot and cold ends in a short time. The temperature control semiconductor layer described in the present invention is filled with a flexible heat insulation material, does not require the use of a ceramic chip for heat conduction, has the characteristics of high flexibility and high thermal resistance, and controls the on-off and direction of the voltage at both ends of the semiconductor refrigerator through PWM regulation to achieve controllable directional transfer of heat energy, meeting the functional requirements of the stretching device for two-way shape memory and large deformation.

[0040] 4. The present invention uses the method of heating the shape memory material by energizing the semiconductor refrigeration layer to replace the traditional method of attaching a flexible heating film to heat / cool the shape memory material, and realizes a stable and controllable two-way shape memory function without the need for continuous energy supply to maintain the stimulation conditions of the shape memory material, greatly reducing the energy consumption of the two-way shape memory folding and unfolding structure of the spacecraft.

[0041] 5. The present invention can be used to realize the function of multiple folding and unfolding of the deployable mechanism of the spacecraft, improving the utilization efficiency of the internal and external space of the spacecraft and the survivability of the deployable mechanism in space. Brief Description of the Drawings

[0042] Figure 1 is the unfolding schematic diagram of the two-way shape memory hinge device based on semiconductor temperature control of the present invention;

[0043] Figure 2 is the folding schematic diagram of the two-way shape memory hinge device based on semiconductor temperature control of the present invention;

[0044] Figure 3 is the stepped cross-sectional schematic diagram of the two-way shape memory hinge device based on semiconductor temperature control of the present invention;

[0045] Figure 4 is the cross-sectional structure schematic diagram of the two-way shape memory hinge device based on semiconductor temperature control of the present invention;

[0046] Figure 5 is the working flow chart of the usage method of the two-way shape memory hinge device based on semiconductor temperature control of the present invention.

[0047] Main Reference Numerals:

[0048] Stretching component 1, temperature-controlled semiconductor layer 11, refrigerating semiconductor grains 111, flexible heat insulation material 112, copper sheet 113, flexible heat conducting material 114, shape memory alloy layer 12, shape memory polymer layer 13, fixture 2. Specific implementation mode

[0049] To elaborate on the technical content, structural features, achieved objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings of the specification.

[0050] The two-way shape memory hinge device based on semiconductor temperature control can achieve the two-way shape memory function in the harsh space environment, realize the repeated controllable deformation of the stretching component 1, and does not require additional energy to maintain the environmental response conditions required for the two-way shape memory. The specific structure of the device of the present invention is as Figure 3 and Figure 4 shown, adopting a multi-layer structure of "shape memory alloy layer 12 - temperature-controlled semiconductor layer 11 - shape memory polymer layer 13", specifically including a stretching component 1 and a fixture 2. The stretching component 1 is flat. Fixtures 2 are symmetrically arranged on both sides of the stretching component 1. The fixtures 2 are used to connect the stretching component 1 with the part that needs to be deployed on the spacecraft. The stretching component 1 can not only be used individually, but also can be connected in series and / or in parallel by multiple ones for use. Adjacent stretching components 1 are connected by the fixtures 2 on both sides.

[0051] Specifically, the fixture 2 is connected to the stretching component 1 by means of adhesion or threading, etc. At the same time, the fixture 2 is also connected to the spacecraft by means of adhesion, threading or welding, etc.; preferably, bolt and nut connection is used.

[0052] In a preferred embodiment of the present invention, the stretching component 1 includes a layer of temperature-controlled semiconductor layer 11 and two layers of shape memory material layers. The shape memory material layer can be a single shape memory alloy, shape memory polymer or a combination of shape memory alloy and shape memory polymer, having different phase change temperatures. The temperature-controlled semiconductor layer 11 is used to heat and / or cool the shape memory material layer. The phase change temperature of the material in the shape memory alloy layer 12 is higher than the phase change temperature of the material in the shape memory polymer layer 13.

[0053] The shape memory material layer includes a shape memory alloy layer 12 and a shape memory polymer layer 13. The temperature-controlled semiconductor layer 11 is located between the shape memory alloy layer 12 and the shape memory polymer layer 13. The temperature-controlled semiconductor layer 11 heats or cools the shape memory material layers on both sides, realizes the active control of the heat flow in the stretching component 1, enables the shape memory alloy and the shape memory polymer to alternately achieve the shape memory effect, and thus realizes the repeated folding and unfolding of the shape memory hinge device.

[0054] The temperature-controlled semiconductor layer 11 includes refrigerating semiconductor grains 111, a flexible heat-insulating material 112, copper sheets 113, and a flexible heat-conducting material 114. The refrigerating semiconductor grains 111 exist in pairs. Since the refrigerating semiconductor grains 111 are brittle materials and cannot deform to adapt to the curvature change of the stretching component 1, a flexible heat-insulating material 112 is provided between adjacent refrigerating semiconductor grains 111. The copper sheets 113 at both ends of the refrigerating semiconductor grains 111 are respectively connected to the bonding surfaces of the shape memory alloy layer 12 and the shape memory polymer layer 13 through the flexible heat-conducting material 114. The copper sheets 111 ensure good electrical conductivity of the refrigerating semiconductor grains 111. The flexible heat-conducting material 114 is used to connect both ends of the refrigerating semiconductor grains 111 to the shape memory alloy and the shape memory polymer to ensure good thermal contact.

[0055] Specifically, the shape memory alloy layer 12 is any one or several of Au-Cd, Ag-Cd, Cu-Zn, Cu-Zn-Al, Cu-Zn-Sn, Cu-Zn-Si, Cu-Sn, Cu-Zn-Ga, In-Ti, Au-Cu-Zn, Ni-Al, Fe-Pt, Ti-Ni, Ti-Ni-Pd, Ti-Ni-Zr, Ti-Nb, U-Nb, or Fe-Mn-Si. The shape memory polymer layer 13 is any one or several of epoxy-based or cyanate-based shape memory polymer resins. The refrigerating semiconductor grains 11 are any one or several of PbTe, ZnSb, SiGe, AgSbTe2, Sb2Te3, Sb2Se3, Sb2Te, Bi2Te3, SbI3, Bi2Se3, or TeI4.

[0056] In the two-way shape memory hinge device of the present invention, the initial shape of the shape memory alloy layer 12 is a flat plate. In a low-temperature environment, a special fixture is used to load the shape memory alloy layer 12. At this time, the martensite in the shape memory alloy reorients, changing from twinned martensite to non-twinned martensite, causing the shape memory alloy layer 12 to deform into a curved plate with a curvature of ρ under the action of residual strain. The initial shapes of the temperature-controlled semiconductor layer 11 and the shape memory polymer layer 13 are both curved plates with a curvature of ρ. The above curved plates with the same curvature are sequentially bonded using an adhesive in the order of the shape memory alloy layer 12, the temperature-controlled semiconductor layer 11, and the shape memory polymer layer 13.

[0057] Furthermore, to control the filling rate and refrigeration / heating power of the refrigerating semiconductor grains 111, the refrigerating semiconductor grains 111 are distributed at intervals of 1.3 mm to 6.2 mm along the bending direction of the stretching component 1, and the refrigerating semiconductor grains 111 are distributed at intervals of 1 mm to 4 mm in the direction perpendicular to the bending direction of the stretching component 1.

[0058] According to the tests, the elastic modulus of the shape memory alloy layer 12 at low temperature (martensite) is 29.5 GPa, and at high temperature (austenite) is 74.4 GPa; the elastic modulus of the shape memory polymer layer 13 at low temperature (glass state) is 3.85 GPa, and at high temperature (rubber state) is 1.05 GPa. The elastic modulus of the flexible thermal insulation material 112 is about 1 GPa. Therefore, in a preferred embodiment of the present invention, the temperature control semiconductor layer 11, the shape memory alloy layer 12, and the shape memory polymer layer 13 are arranged in a thickness ratio of 1:5:7, and the total thickness d of the final deployment assembly 1 is 3 mm to 15 mm. The bending radius ρ 1 of the deployment assembly 1 in the deployed state is 6 mm to 30 mm.

[0059] The temperature control system connected to the temperature control semiconductor layer 11 is a driving chip composed of field effect transistors forming an H-bridge. By adopting pulse width modulation technology, that is, the PWM duty cycle adjustment method, to control the on-off of the voltage across the refrigeration semiconductor crystal grains 111.

[0060] The bending neutral plane of the deployment assembly 1 is located inside the temperature control semiconductor layer 11. The strain expression of the shape memory alloy layer 12 in the deployment assembly 1 is:

[0061]

[0062] where ρ(t) is the bending radius of the bending neutral plane of the deployment assembly 1, the bending radius ρ(t) changes with time, a is the thickness of the shape memory alloy layer 12, and b 1 is the distance from the bending neutral plane of the deployment assembly 1 to the bonding surface of the shape memory alloy layer 12.

[0063] The strain expression of the shape memory polymer layer 13 in the deployment assembly 1 is:

[0064]

[0065] where ρ(t) is the bending radius of the bending neutral plane of the deployment assembly 1, the bending radius ρ(t) changes with time, ρ is the bending radius during the manufacture of the deployment assembly 1, c is the thickness of the shape memory polymer layer 13, and b 1 is the distance from the bending neutral plane of the deployment assembly 1 to the bonding surface of the shape memory alloy layer 12, and b 2 is the distance from the bending neutral plane of the deployment assembly 1 to the bonding surface of the shape memory polymer layer 13.

[0066] The strain expression of the temperature control semiconductor layer 11 in the deployment assembly 1 is:

[0067]

[0068] Wherein, ρ(t) is the bending radius of the bending neutral plane of the stretching component 1, and the bending radius ρ(t) varies with time. ρ is the bending radius when the stretching component 1 is manufactured, and b 1 is the distance from the bending neutral plane of the stretching component 1 to the bonding surface of the shape memory alloy layer 12, and b 2 is the distance from the bending neutral plane of the stretching component 1 to the bonding surface of the shape memory polymer layer 13.

[0069] In the two-way shape memory hinge device of the present invention, the tensile strain of the flexible heat insulation material 112 needs to be less than 25%. According to the strain expression of the temperature control semiconductor layer 11, the filling rate of the refrigeration semiconductor grains 111 inside the temperature control semiconductor layer 11 along the folding and unfolding direction needs to be controlled to be less than 40%. Further, in order to ensure the unfolding rate and structural reliability of the stretching component 1, the maximum refrigeration / heating power of the temperature control semiconductor layer 11 is not less than 0.6 w / cm2. The length of the selected refrigeration semiconductor grains 111 is 0.7 to 0.9 times the thickness of the temperature control semiconductor layer 11, that is, 0.8 mm to 5.2 mm; the cross-section of the refrigeration semiconductor grains 111 is a rectangle with a side length of 1 to 3 mm.

[0070] In a preferred embodiment of the present invention, when the stretching component 1 is in the folded state, the shape memory alloy layer 12 has the maximum strain, and the specific expression is as follows:

[0071]

[0072] Wherein, a is the thickness of the shape memory alloy layer 12, and b 1 is the distance from the bending neutral plane of the stretching component 1 to the bonding surface of the shape memory alloy layer 12, and ρ 1 is the bending radius of the stretching component 1 in the unfolded state.

[0073] When the stretching component 1 is in the unfolded state, the temperature control semiconductor layer 11 has the maximum strain, and the specific expression is as follows:

[0074]

[0075] Wherein, b 2 is the distance from the bending neutral plane of the stretching component 1 to the bonding surface of the shape memory polymer layer 13, and ρ 1 is the bending radius of the stretching component 1 in the unfolded state, and ρ is the bending radius when the stretching component 1 is manufactured.

[0076] Meanwhile, the shape memory polymer layer 13 also has the maximum strain, and the specific expression is as follows:

[0077]

[0078] Wherein, b 2is the distance from the bending neutral plane of the stretching component 1 to the bonding surface of the shape memory polymer layer 13, c is the thickness of the shape memory polymer layer 13, and ρ 1 is the bending radius of the stretching component 1 in the unfolded state, and ρ is the bending radius during the manufacturing of the stretching component 1.

[0079] Furthermore, the main working principles of the materials used in the temperature-controlled semiconductor layer 11, the shape memory alloy layer 12, and the shape memory polymer layer 13 in the dual-memory shape memory hinge device of the present invention are as follows:

[0080] There are various types of shape memory polymers (SMP) in the shape memory polymer layer 13, mainly including thermally induced, photoinduced, electroinduced, magnetically induced, and chemically induced types. Among them, thermoplastic shape memory polymers are in a high-strength glassy state at the phase transition temperature t g and below, and turn into a highly elastic rubbery state at the phase transition temperature t g and above. When the thermoplastic shape memory polymer is heated to a temperature above t g , loaded, and cooled, residual strain will occur, and this residual strain will disappear after reheating.

[0081] There are mainly two metallographic phases in the shape memory alloy (SMA) in the shape memory alloy layer 12: the low-temperature martensite phase and the high-temperature austenite phase. When the shape memory alloy is loaded and unloaded at low temperature, there is residual strain after unloading. At this time, when the shape memory alloy is heated and exceeds its austenite phase transition temperature, the residual strain will disappear and the alloy will return to its initial shape. The Brinson model describing its macroscopic phenomenological constitutive equation is as follows:

[0082] σ - σ 0 = E(ε - ε 0 ) + Ω S (ξ S - ξ S0 ) + Ω T (ξ T - ξ T0 ) + Θ(T - T 0 )

[0083] where σ, σ 0 are the stress and initial stress of the SMA; ε, ε 0 are the strain and initial strain of the SMA; T, T 0 are the temperature and initial temperature of the SMA; ξ S , ξ S0 are the martensite content and initial content caused by stress; ξ T , ξ T0 are the martensite content and initial content caused by temperature; E is the elastic modulus of the SMA; Ω S , Ω Tis the phase change modulus caused by stress and temperature; Θ is the thermoelastic modulus.

[0084] Since the thermoelastic modulus is much smaller than the phase change modulus, the Brinson model can be simplified as:

[0085] σ = [ξE M +(1 - ξ)E A (ε - ε L ξ)

[0086] ξ = ξ S + ξ T

[0087] where E M is the pure martensite elastic modulus; E A is the pure austenite elastic modulus; ε L is the maximum residual strain of SMA.

[0088] The temperature-controlled semiconductor layer 11 uses the thermoelectric refrigeration technology, also known as the Peltier effect. When direct current passes through a loop composed of two different conductive materials, heat absorption or heat release will occur at the nodes. When the current direction changes, the direction of heat conduction also changes. In the prior art, semiconductor grains are mainly attached pairwise between two ceramics to achieve heat conduction.

[0089] The structure of the dual - path shape memory hinge device of the present invention has the advantages of small weight, easy realization of self - locking and self - unfolding functions, small deployment impact, and large stiffness compared with the traditional mechanical stretching device. The present invention breaks the limitation that the previous dual - path shape memory material needs to maintain an external stimulus to maintain deformation, and can control the temperature of each shape memory material layer by changing the current direction passing through the semiconductor, realizing the repeated and controllable deformation of the stretching component. The present invention can achieve the dual - path shape memory function in the harsh space environment, greatly reducing the energy required for realizing the dual - path shape memory in the aerospace field and providing new ideas for space folding and unfolding mechanisms.

[0090] The following further describes the usage method of a dual - path shape memory hinge device based on semiconductor temperature control of the present invention in combination with embodiments:

[0091] In this embodiment, T 0 represents the equilibrium temperature of the external environment, T 1 represents the phase change temperature of the shape memory polymer, and T 2 represents the phase change temperature of the shape memory alloy. In the initial state, the temperatures of the shape memory alloy layer 12 and the shape memory polymer layer 13 are both the environmental equilibrium temperature T 0 , the shape memory alloy layer 12 is in the martensite state, and the shape memory polymer layer 13 is in the glass state.

[0092] Usage method of a two-way shape memory hinge device based on semiconductor temperature control, as Figure 5 shown, Figure 5 In the figure, state A is the initial state, state B is the retracted state, and state C is the deployed state. The states of the materials in each stage are shown in Table 1, and specifically include the following steps:

[0093] S1. When the two-way shape memory hinge device is in the initial retracted state, as Figure 2 shown, apply alternating current to the refrigerating semiconductor grains 111 in the temperature control semiconductor layer 11, so that the shape memory alloy layer 12 and the shape memory polymer layer 13 located at both ends of the refrigerating semiconductor grains 111 are heated until the shape memory alloy layer 12 reaches the phase transition temperature T 2 , and the shape memory polymer layer 13 reaches the phase transition temperature T 1 . At this time, the shape memory alloy transforms from martensite to austenite, the elastic modulus increases and the initial shape is restored. The shape memory polymer transforms into a rubber state, and the elastic modulus rapidly decreases. The shape memory alloy layer 12 overcomes the resistance of the temperature control semiconductor layer 11 and the shape memory polymer layer 13, and changes the hinge device from the retracted state to the deployed state.

[0094] S2. When the two-way shape memory hinge device is in the deployed state of step S1, as Figure 1 shown, apply direct current to the refrigerating semiconductor grains 111 in the temperature control semiconductor layer 11, so that the shape memory alloy layer 12 located at the first end of the refrigerating semiconductor grains 111 is heated. At this time, the temperature of the shape memory alloy layer 12 reaches the phase transition temperature T 2 and remains in the deployed state, and the shape memory polymer layer 13 located at the second end of the refrigerating semiconductor grains 111 is cooled. At this time, the temperature of the shape memory polymer layer 13 is lower than the phase transition temperature T 1 , and it transforms into a high-strength glass state.

[0095] S3. On the basis of step S2, stop applying direct current to the refrigerating semiconductor grains 111 in the temperature control semiconductor layer 11. At this time, under the equilibrium temperature T 0 of the external environment, each part of the stretching component 1 radiates to the external environment to slowly cool down to the equilibrium temperature T 0 . The shape memory alloy transforms into martensite. The shape memory alloy layer 12 and the shape memory polymer layer 13 overcome the resistance of the temperature control semiconductor layer 11, so that the two-way shape memory hinge device maintains the deployed state and realizes self-locking. The two-way shape memory hinge device in this state can be maintained for a long time without energy supply.

[0096] S4. When the dual - path shape - memory hinge device needs to be folded when it is in the deployed state, a direct current opposite to the direction in step S2 is applied to the refrigerating semiconductor grains 111 in the temperature - controlled semiconductor layer 11, so that the shape - memory polymer layer 13 at the second end of the refrigerating semiconductor grains 111 is heated. At this time, the temperature of the shape - memory polymer layer 13 is higher than the phase - change temperature T 1 , the shape - memory polymer is in a rubber state and has a large recoverable strain; the shape - memory alloy layer 12 at the first end of the refrigerating semiconductor grains 111 is cooled. At this time, the temperature of the shape - memory alloy layer 12 is lower than the phase - change temperature T 2 , the shape - memory alloy is in a martensite state, has a small elastic modulus and can have a large residual strain; the shape - memory polymer layer 13 overcomes the resistance of the temperature - controlled semiconductor layer 11 and the shape - memory alloy layer 12, slowly eliminates the residual strain, and makes the dual - path shape - memory hinge device recover from the self - locking deployed state to the folded state.

[0097] S5. When the dual - path shape - memory hinge device is in the folded state of step S5, the power supply of direct current to the refrigerating semiconductor grains 111 in the temperature - controlled semiconductor layer 11 is stopped. At this time, at the equilibrium temperature T of the external environment 0 , the shape - memory polymer layer 13 radiates to the external environment to slowly cool down to the phase - change temperature T 1 and below, and further cools down to the equilibrium temperature T 0 , the shape - memory polymer transforms into a high - strength glass state, making the dual - path shape - memory hinge device maintain the folded state and achieve self - locking.

[0098] If the dual - path shape - memory hinge device needs to be deployed and folded again, repeat S1 to S5.

[0099] Table 1 States of the dual - path shape - memory hinge device at each stage

[0100]

[0101]

[0102] In the field of aerospace technology, compared with the traditional mechanical stretching device, the dual - path shape - memory hinge device of the present invention can effectively reduce the weight of the folding and unfolding device, can realize the self - locking and self - unfolding functions, and adopts the composite structure of shape - memory alloy and shape - memory polymer to achieve the strength complementarity of the shape - memory hinge at various temperatures. Its deployment process has a large damping and a small deployment impact, and can be used for connecting external components of spacecraft to realize the function of repeated folding and unfolding.

[0103] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various modifications and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A two-way shape memory hinge device based on semiconductor temperature control, which includes an extension component and a fixture. The extension component is flat, and fixtures are symmetrically arranged on both sides of the extension component. It is characterized in that The extension component includes a temperature-controlled semiconductor layer and a shape memory material layer. The shape memory material layer includes a shape memory alloy layer and a shape memory polymer layer. The temperature-controlled semiconductor layer is located between the shape memory alloy layer and the shape memory polymer layer. The temperature-controlled semiconductor layer realizes the active control of the heat flow in the extension component, enabling the shape memory alloy and the shape memory polymer to alternately achieve the shape memory effect. The temperature-controlled semiconductor layer includes refrigerating semiconductor grains, a flexible heat insulation material, copper sheets, and a flexible heat conduction material. The refrigerating semiconductor grains exist in pairs, and the flexible heat insulation material is arranged between adjacent refrigerating semiconductor grains. The copper sheets located at both ends of the refrigerating semiconductor grains are respectively connected to the bonding surfaces of the shape memory alloy layer and the shape memory polymer layer through the flexible heat conduction material. The refrigerating semiconductor grains are distributed along the bending direction of the extension component at a spacing of 1.3 mm to 6.2 mm, and the refrigerating semiconductor grains are distributed in the direction perpendicular to the bending direction of the extension component at a spacing of 1 mm to 4 mm, so as to ensure the filling rate of the refrigerating semiconductor grains and the refrigerating and heating power. The bending neutral plane of the extension component is located inside the temperature-controlled semiconductor layer. In the extension component, the strain expression of the shape memory alloy layer is: The strain expression of the shape memory polymer layer in the extension component is: The strain expression of the temperature-controlled semiconductor layer in the extension component is: When the extension component is in the retracted state, the shape memory alloy layer has the maximum strain, and the specific expression is as follows: When the extension component is in the unfolded state, the temperature-controlled semiconductor layer has the maximum strain, and the specific expression is as follows: When the extension component is in the unfolded state, the shape memory polymer layer has the maximum strain, and the specific expression is as follows: Among them, ε SMAmax , ε SMAmin are respectively the maximum strain and the minimum strain of the shape memory alloy layer in the stretching component, ε SMPmax , ε SMPmin are respectively the maximum strain and the minimum strain of the shape memory polymer layer in the stretching component, ε 控温max , ε 控温min are respectively the maximum strain and the minimum strain of the temperature control semiconductor layer in the stretching component, ρ(t) is the bending radius of the bending neutral plane of the stretching component, a is the thickness of the shape memory alloy layer, b 1 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory alloy layer, ρ is the bending radius during the manufacture of the stretching component, c is the thickness of the shape memory polymer layer, b 2 is the distance from the bending neutral plane of the stretching component to the bonding surface of the shape memory polymer layer, ρ 1 is the bending radius of the stretching component in the unfolded state.

2. The two-way shape memory hinge device based on semiconductor temperature control according to claim 1, It is characterized in that The bending radius ρ of the extension component in the deployed state 1 is 6 mm to 30 mm.

3. The two-way shape memory hinge device based on semiconductor temperature control according to claim 1, It is characterized in that The length of the refrigerating semiconductor grains is 0.7 to 0.9 times the thickness of the temperature-controlled semiconductor layer, and the cross-section of the refrigerating semiconductor grains is a rectangle with a side length of 1 mm to 3 mm.

4. The two-way shape memory hinge device based on semiconductor temperature control according to claim 1, It is characterized in that The temperature control system connected to the temperature-controlled semiconductor layer is a driving chip composed of field effect transistors forming an H-bridge.

5. The two-way shape memory hinge device based on semiconductor temperature control according to claim 1 or 2, It is characterized in that The total thickness d of the extension component is 3 - 15 mm.

6. The two-way shape memory hinge device based on semiconductor temperature control according to claim 1, It is characterized in that The shape memory alloy layer is any one or several of Au-Cd, Ag-Cd, Cu-Zn, Cu-Zn-Al, Cu-Zn-Sn, Cu-Zn-Si, Cu-Sn, Cu-Zn-Ga, In-Ti, Au-Cu-Zn, Ni-Al, Fe-Pt, Ti-Ni, Ti-Ni-Pd, Ti-Ni-Zr, Ti-Nb, U-Nb or Fe-Mn-Si. The shape memory polymer layer is any one or several of epoxy-based or cyanate-based shape memory polymer resins. The refrigerating semiconductor grains are any one or several of PbTe, ZnSb, SiGe, AgSbTe2, Sb2Te3, Sb2Se3, Sb2Te, Bi2Te3, SbI3, Bi2Se3 or TeI4.

7. A method for using a two-way shape memory hinge device based on semiconductor temperature control according to any one of claims 1-6, characterized in that, it comprises the following steps: S1. When the two-way shape memory hinge device is in the initial folded state, apply alternating current to the refrigerating semiconductor grains in the temperature control semiconductor layer, so that the shape memory alloy layer and the shape memory polymer layer located at both ends of the refrigerating semiconductor grains are heated until the temperatures of the shape memory alloy layer and the shape memory polymer layer are both higher than their respective phase transition temperatures. At this time, use the characteristics of the shape memory alloy and the shape memory polymer to change the two-way shape memory hinge device from the folded state to the unfolded state; S2. When the two-way shape memory hinge device is in the unfolded state of step S1, apply direct current to the refrigerating semiconductor grains in the temperature control semiconductor layer, so that the shape memory alloy layer located at the first end of the refrigerating semiconductor grains is heated. At this time, the temperature of the shape memory alloy layer is higher than its own phase transition temperature and remains in the unfolded state, and the shape memory polymer layer located at the second end of the refrigerating semiconductor grains is cooled. At this time, the temperature of the shape memory polymer layer is lower than its own phase transition temperature; S3. On the basis of step S2, stop applying alternating current and direct current to the refrigerating semiconductor grains in the temperature control semiconductor layer. At this time, in the external environment, the shape memory alloy layer and the shape memory polymer layer overcome the resistance of the temperature control semiconductor layer, so that the two-way shape memory hinge device changes from the unfolded state to the folded state and maintains the unfolded state to achieve self-locking; S4. When the two-way shape memory hinge device is being folded in the self-locked state, apply direct current in the opposite direction to that in step S2 to the refrigerating semiconductor grains in the temperature control semiconductor layer, so that the shape memory polymer layer located at the second end of the refrigerating semiconductor grains is heated. At this time, the temperature of the shape memory polymer layer is higher than its own phase transition temperature, and the shape memory alloy layer located at the first end of the refrigerating semiconductor grains is cooled. At this time, the temperature of the shape memory alloy layer is lower than its own phase transition temperature. The shape memory polymer layer overcomes the resistance of the temperature control semiconductor layer and the shape memory alloy layer, so that the two-way shape memory hinge device is restored from the self-locked unfolded state to the folded state; S5. When the double - way shape - memory hinge device is in the folded state of step S4, stop applying DC power to the refrigerating semiconductor grains in the temperature - controlling semiconductor layer. At this time, in the external environment, the shape - memory polymer layer cools down to below its phase - change temperature, so that the double - way shape - memory hinge device maintains the folded state and realizes self - locking.

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