An electret thin-film deflection device and method with adjustable range and self-sensing function

Abstract

An adjustable-range electret thin-film deflection device and method with self-sensing function is disclosed. The device includes an upper cover and a bottom shell connected to the upper cover. From top to bottom, an upper electrode plate, an upper gap adjustment plate, a composite electret thin film, a lower gap adjustment plate, and a lower electrode plate are coaxially arranged within the upper cover and bottom shell. The composite electret thin film, possessing net charge characteristics, is sandwiched between the upper cover and bottom shell, serving as both the driving and sensing element. This device has a simple and compact structure, small size, and simultaneously integrates sensing and actuation functions, enabling high-precision output of two-dimensional deflection angles. Furthermore, the output angle range, natural frequency, sensing sensitivity, and force-to-electricity conversion capability of the device can be adjusted and controlled by adjusting the distance between the upper and lower electrode plates or the pre-stretch ratio of the composite electret thin film.

Description

Technical Field

[0001] This invention relates to the field of deflection device technology, specifically to an electret thin-film deflection device and method with adjustable range and self-sensing function. Background Technology

[0002] With the continuous development of aerospace technology, the political and military fields of various countries have placed higher demands on the development of technologies such as satellite communication, Earth observation, and antenna profile adjustment and control, making the application of high-performance pointing mechanisms increasingly urgent. A deflector device refers to a mechanism that can control the two-dimensional deflection and pointing motion of its reflector load, thereby achieving multi-degree-of-freedom precise pointing adjustment of satellite payloads. It has become a key actuation device for payloads such as optical imaging systems and precise antenna pointing systems. Currently, most deflector devices used are piezoelectric ceramic and electromagnetically driven, requiring complex structures to complete the deflection motion. Furthermore, to meet the requirements of high precision and large deflection angles, they all require additional sensing devices to measure the deflection angle. Summary of the Invention

[0003] In order to overcome the technical problems existing in the prior art, the present invention aims to provide an electret thin film deflection device and method with adjustable range and self-sensing function. The output angle range, natural frequency, sensing sensitivity and force-to-electricity conversion capability of the device are adjustable and controllable.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] An electret thin-film deflection device with adjustable range and self-sensing function includes a device cover 1, a device base 2 connected to the device cover 1, and an upper electrode plate 3, an upper gap adjustment plate 4, a composite electret thin film 5, a lower gap adjustment plate 6, and a lower electrode plate 7, which are coaxially arranged from top to bottom within the device cover 1 and the device base 2. The upper electrode plate 3 and the upper gap adjustment plate 4 are nested within the device cover 1; the lower gap adjustment plate 6 and the lower electrode plate 7 are nested within the device base 2; and the composite electret thin film 5 is sandwiched between the device cover 1 and the device base 2, serving as a driving and sensing element. The sensing signal acquisition device 8 is electrically connected to the upper electrode plate 3 and the lower electrode plate 7, and outputs corresponding sensing signals. The sensing signal acquisition device 8 is also connected to the controller 9. When a real-time actuation signal is required, the controller 9 processes the real-time sensing signal received from the sensing signal acquisition device 8 and controls the power amplifier 10, which is also connected to the upper electrode plate 3 and the lower electrode plate 7, to complete the output of the control actuation signal. At this time, the composite electret film 5, which serves as both the driving and sensing element, is subjected to the potential difference between the upper electrode plate 3 and the lower electrode plate 7, thereby completing the corresponding yaw actuation.

[0006] The upper electrode plate 3 and the lower electrode plate 7 have the same electrode arrangement. The upper electrode plate 3 has eight electrode plates arranged on it, namely, a first deflection angle actuation electrode 3-1-1, a second deflection angle actuation electrode 3-1-2, a third deflection angle actuation electrode 3-1-3, and a fourth deflection angle actuation electrode 3-1-4 for performing deflection angle actuation; and a first deflection angle sensing and measuring electrode 3-2-1, a second deflection angle sensing and measuring electrode 3-2-2, a third deflection angle sensing and measuring electrode 3-2-3, and a fourth deflection angle sensing and measuring electrode 3-2-4 for performing deflection angle sensing and measuring. The first deflection angle actuation electrode 3-1-1 and the second deflection angle actuation electrode 3-1-2 are arranged opposite each other, together controlling the composite electret thin film. The membrane 5 completes a deflection motion in the Y direction. The first deflection angle sensing and measuring electrode 3-2-1 and the second deflection angle sensing and measuring electrode 3-2-2 are arranged opposite to each other to measure the deflection angle of the composite electret film 5 in the Y direction. The third deflection angle actuating electrode 3-1-3 and the fourth deflection angle actuating electrode 3-1-4 are arranged opposite to each other to control the composite electret film 5 to complete a deflection motion in the X direction. The third deflection angle sensing and measuring electrode 3-2-3 and the fourth deflection angle sensing and measuring electrode 3-2-4 are arranged opposite to each other to measure the deflection angle of the composite electret film 5 in the X direction. The controller 9 controls the control signals applied to each deflection angle actuating electrode to complete the two-dimensional deflection motion of the composite electret film 5.

[0007] The first deflection angle actuating electrode 3-1-1, the third deflection angle actuating electrode 3-1-3, the second deflection angle actuating electrode 3-1-2, and the fourth deflection angle actuating electrode 3-1-4 are arranged sequentially in the outer ring, and the first deflection angle sensing and measuring electrode 3-2-1, the third deflection angle sensing and measuring electrode 3-2-3, the second deflection angle sensing and measuring electrode 3-2-2, and the fourth deflection angle sensing and measuring electrode 3-2-4 are arranged sequentially in the inner ring.

[0008] The composite electret film 5 is a dielectric elastomer material with adjustable elastic modulus, and it is doped with nano-electret particles that have been pre-polarized with net charge, giving it a long-lasting negative charge retention characteristic. The charge density pre-applied to the nano-electret particles is related to the type, quantity, and polarization conditions of the nano-electret particles. In addition, as a dielectric elastomer material, it also has the characteristics of low elastic modulus and stretchability. During stretching, its total net charge remains unchanged, while the equivalent charge surface density decreases. Therefore, by adjusting the pre-stretch rate of the composite electret film 5 located between the device upper cover 1 and the device bottom shell 2, the force-to-electric conversion capability, sensing sensitivity, natural frequency, and maximum deflection angle of the deflection device can be adjusted and controlled, increasing the application scenarios of the deflection device.

[0009] The operation and sensing method of the adjustable-range electret thin-film deflection device with self-sensing function involves applying voltage signals to the upper electrode plate 3 and the lower electrode plate 7 through the power amplifier 10 during operation. The potential difference between the upper electrode plate 3 and the lower electrode plate 7 attracts or repels the composite electret thin film 5 with net charge characteristics, thereby outputting the deflection angle. Furthermore, since this attraction or repulsion force is an electrostatic force, the electric field can be adjusted by changing the gap between the upper electrode plate 3 and the lower electrode plate 7, i.e., increasing or decreasing the thickness of the upper gap adjustment plate 4 and the lower gap adjustment plate 6. This allows for mechanical adjustment of the electrostatic force, making the output angle range and electromechanical conversion efficiency of the deflection device adjustable and controllable. Simultaneously, during sensing, due to the unique net charge retention characteristics of the composite electret film 5, when the composite electret film 5 undergoes a certain deflection motion, according to the electrostatic induction theory, the electrostatic balance on the upper electrode plate 3 and the lower electrode plate 7 will be broken. A corresponding charge surge will occur within the sensing and acquisition device 8 connected to the upper electrode plate 3 and the lower electrode plate 7. By detecting this charge surge, the deflection angle of the composite electret film 5 can be measured.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] 1. The composite electret thin-film deflection device with adjustable range and self-sensing function described in this invention has a simple and compact structure, small size, large output deflection angle, and long life.

[0012] 2. The range-adjustable composite electret thin film deflection device of the present invention uses a composite electret thin film to enable the device to have force-to-electric conversion capability, while also having sensing and actuation capabilities, thus enabling the deflection device to have self-sensing capability.

[0013] 3. The composite electret thin-film deflection device with adjustable range and self-sensing function described in this invention mechanically adjusts the working power by designing the thickness of the upper and lower gap adjustment plates, so that the maximum deflection angle and electromechanical conversion efficiency of the device are adjustable and controllable.

[0014] 4. The composite electret thin film deflection device with adjustable range and self-sensing function described in this invention makes the force-to-electric conversion capability of the device adjustable and controllable by designing the pre-stretch ratio of the composite electret thin film, and can adjust the sensing sensitivity, natural frequency and driving capability of the device. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of the composite electret thin-film deflection device with adjustable range and self-sensing function of the present invention.

[0016] Figure 2This is a cross-sectional view of the composite electret thin-film deflection device of the present invention, which has an adjustable range and self-sensing function.

[0017] Figure 3 This is an exploded view of the composite electret thin-film deflection device of the present invention, which has an adjustable range and self-sensing function.

[0018] Figure 4 This is a schematic diagram of the upper and lower electrode plates of the composite electret thin-film deflection device of the present invention, which has an adjustable range and self-sensing function.

[0019] Figure 5 This is a schematic diagram illustrating the operation and sensing principle of the composite electret thin-film deflection device with adjustable range and self-sensing function of the present invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 and Figure 2 As shown, an electret thin-film deflection device with adjustable range and self-sensing function includes a device cover 1, a device base shell 2 connected to the device cover 1, and an upper electrode plate 3, an upper gap adjustment plate 4, a composite electret thin film 5, a lower gap adjustment plate 6, and a lower electrode plate 7, which are coaxially arranged from top to bottom within the device cover 1 and the device base shell 2. The upper electrode plate 3 and the upper gap adjustment plate 4 are nested within the device cover 1; the lower gap adjustment plate 6 and the lower electrode plate 7 are nested within the device base shell 2; and the composite electret thin film 5 is sandwiched between the device cover 1 and the device base shell 2, serving as a driving and sensing element. A sensing signal acquisition device 8 is electrically connected to the upper electrode plate 3 and the lower electrode plate 7, outputting corresponding sensing signals. Furthermore, the sensor signal acquisition device 8 is connected to the controller 9. When a real-time actuation signal is required, the controller 9 processes the real-time sensor signal received from the sensor signal acquisition device 8 and controls the power amplifier 10, which is also connected to the upper electrode plate 3 and the lower electrode plate 7, to complete the output of the control actuation signal. At this time, the composite electret film 5, which serves as both the driving and sensing element, is subjected to the potential difference between the upper electrode plate 3 and the lower electrode plate 7, thereby completing the corresponding yaw actuation.

[0022] like Figure 4As shown, the upper electrode plate 3 and the lower electrode plate 7 have the same electrode arrangement. The upper electrode plate 3 will be described in detail here. Eight electrode plates are arranged on the upper electrode plate 3, which are divided into the first deflection angle actuation electrode 3-1-1, the second deflection angle actuation electrode 3-1-2, the third deflection angle actuation electrode 3-1-3, and the fourth deflection angle actuation electrode 3-1-4 arranged on the outer ring for performing deflection angle actuation; and the first deflection angle sensing and measuring electrode 3-2-1, the second deflection angle sensing and measuring electrode 3-2-2, the third deflection angle sensing and measuring electrode 3-2-3, and the fourth deflection angle sensing and measuring electrode 3-2-4 arranged on the inner ring for performing deflection angle sensing and measuring. The first deflection angle actuating electrode 3-1-1 and the second deflection angle actuating electrode 3-1-2 are arranged opposite each other to control the composite electret film 5 to complete the deflection motion in the Y direction. Similarly, the first deflection angle sensing and measuring electrode 3-2-1 and the second deflection angle sensing and measuring electrode 3-2-2 are arranged opposite each other to measure the deflection angle of the composite electret film 5 in the Y direction. Likewise, the third deflection angle actuating electrode 3-1-3 and the fourth deflection angle actuating electrode are arranged opposite each other to control the composite electret film 5 to complete the deflection motion in the X direction. The third deflection angle sensing and measuring electrode 3-2-3 and the fourth deflection angle sensing and measuring electrode are arranged opposite each other to measure the deflection angle of the composite electret film 5 in the X direction. By controlling the control signals applied to each deflection angle actuating electrode through the controller 9, the two-dimensional deflection motion of the composite electret film 5 can be completed.

[0023] like Figure 5 As shown, the operation and sensing method of the adjustable-range electret thin-film deflection device with self-sensing function is as follows. During operation, the upper electrode plate 3 and the lower electrode plate 7 are subjected to voltage signals through the power amplifier 10. The potential difference between the upper electrode plate 3 and the lower electrode plate 7 attracts or repels the composite electret thin film 5 with net charge characteristics, thereby realizing the output of the deflection angle. Furthermore, since this attraction or repulsion force is an electrostatic force, the electric field magnitude can be adjusted by changing the gap between the upper electrode plate 3 and the lower electrode plate 7, i.e., increasing or decreasing the thickness of the upper gap adjustment plate 4 and the lower gap adjustment plate 6, thereby achieving the purpose of mechanically adjusting the magnitude of the electrostatic force. This makes the output angle range and electromechanical conversion efficiency of the deflection device adjustable and controllable. Meanwhile, during sensing, due to the unique net charge retention characteristics of the composite electret film 5, when the composite electret film 5 undergoes a certain deflection motion, according to the electrostatic induction theory, the electrostatic balance on the upper electrode plate 3 and the lower electrode plate 7 will be broken, and a corresponding charge surge will appear in the sensing and acquisition device 8 connected to the upper electrode plate 3 and the lower electrode plate 7. By detecting this charge surge, the deflection angle of the composite electret film 5 can be measured.

[0024] Preferably, the composite electret film 5 is a dielectric elastomer material with adjustable elastic modulus, and it is doped with nano-electret particles pre-polarized with net charge, giving it a long-lasting negative charge retention characteristic. Furthermore, the pre-polarized charge density of the nano-electret particles is related to the type, quantity, and polarization conditions of the nano-electret particles. In addition, as an elastomer material, it also has characteristics such as low elastic modulus and stretchability. Because its total net charge remains constant during stretching, while the equivalent charge surface density decreases, the pre-stretching rate of the composite electret film 5 located between the device's upper cover 1 and bottom shell 2 can be adjusted, making the force-to-electric conversion capability, sensing sensitivity, natural frequency, and maximum deflection angle of the deflection device adjustable and controllable, greatly expanding the application scenarios of the deflection device.

Claims

1. A range-adjustable electret thin-film deflection device with self-sensing function, characterized in that: The device includes an upper cover (1) and a lower shell (2) connected to the upper cover (1). From top to bottom, the device consists of an upper electrode plate (3), an upper gap adjustment plate (4), a composite electret film (5), a lower gap adjustment plate (6), and a lower electrode plate (7), which are coaxially arranged within the upper cover (1) and the lower shell (2). The upper electrode plate (3) and the upper gap adjustment plate (4) are nested within the upper cover (1); the lower gap adjustment plate (6) and the lower electrode plate (7) are nested within the lower shell (2); the composite electret film (5) is sandwiched between the upper cover (1) and the lower shell (2) as a driving and sensing element; and the sensing signal is acquired. The device (8) is electrically connected to the upper electrode plate (3) and the lower electrode plate (7) and outputs corresponding sensing signals. The sensing signal acquisition device (8) is connected to the controller (9). When a real-time actuation signal is required, the controller (9) processes the real-time sensing signal received from the sensing signal acquisition device (8) and controls the power amplifier (10), which is also connected to the upper electrode plate (3) and the lower electrode plate (7), to complete the output of the control actuation signal. At this time, the composite electret film (5), which serves as both the driving and sensing element, is subjected to the potential difference between the upper electrode plate (3) and the lower electrode plate (7) to complete the corresponding yaw actuation.

2. The electret thin-film deflection device according to claim 1, characterized in that: The upper electrode plate (3) and the lower electrode plate (7) have the same electrode arrangement. The upper electrode plate (3) is provided with eight electrode plates, namely, a first deflection angle actuation electrode (3-1-1), a second deflection angle actuation electrode (3-1-2), a third deflection angle actuation electrode (3-1-3), and a fourth deflection angle actuation electrode (3-1-4) for performing deflection angle actuation; and a first deflection angle sensing and measuring electrode (3-2-1), a second deflection angle sensing and measuring electrode (3-2-2), a third deflection angle sensing and measuring electrode (3-2-3), and a fourth deflection angle sensing and measuring electrode (3-2-4) for performing deflection angle sensing and measuring; wherein the first deflection angle actuation electrode (3-1-1) and the second deflection angle actuation electrode (3-1-2) are arranged opposite to each other and together control the composite electret. The thin film (5) completes the deflection motion in the Y direction. The first deflection angle sensing and measuring electrode (3-2-1) and the second deflection angle sensing and measuring electrode (3-2-2) are arranged opposite to each other to complete the measurement of the deflection angle of the composite electret thin film (5) in the Y direction. The third deflection angle actuating electrode (3-1-3) and the fourth deflection angle actuating electrode (3-1-4) are arranged opposite to each other to control the composite electret thin film (5) to complete the deflection motion in the X direction. The third deflection angle sensing and measuring electrode (3-2-3) and the fourth deflection angle sensing and measuring electrode (3-2-4) are arranged opposite to each other to complete the measurement of the deflection angle of the composite electret thin film (5) in the X direction. The controller (9) controls the control signal applied to each deflection angle actuating electrode to complete the two-dimensional deflection motion of the composite electret thin film (5).

3. The electret thin-film deflection device according to claim 2, characterized in that: The first deflection angle actuation electrode (3-1-1), the third deflection angle actuation electrode (3-1-3), the second deflection angle actuation electrode (3-1-2), and the fourth deflection angle actuation electrode (3-1-4) are arranged sequentially on the outer ring, and the first deflection angle sensing and measuring electrode (3-2-1), the third deflection angle sensing and measuring electrode (3-2-3), the second deflection angle sensing and measuring electrode (3-2-2), and the fourth deflection angle sensing and measuring electrode (3-2-4) are arranged sequentially on the inner ring.

4. The electret thin-film deflection device according to claim 1, characterized in that: The composite electret film (5) is a dielectric elastomer material with adjustable elastic modulus, and it is doped with nano electret particles that have been pre-polarized with net charge, giving it a long-lasting negative charge retention characteristic. The charge density pre-applied to the nano electret particles is related to the type, quantity, and polarization conditions of the nano electret particles. In addition, as a dielectric elastomer material, it also has the characteristics of low elastic modulus and stretchability. During the stretching process, its total net charge remains unchanged, while the equivalent charge surface density decreases. Therefore, by adjusting the pre-stretching rate of the composite electret film (5) located between the device top cover (1) and the device bottom shell (2), the force-to-electric conversion capability, sensing sensitivity, natural frequency, and maximum deflection angle of the deflection device can be adjusted and controlled, increasing the application scenarios of the deflection device.

5. The actuation and sensing method of the electret thin-film deflection device with adjustable range and self-sensing function as described in any one of claims 1 to 4, characterized in that: During operation, the upper electrode plate (3) and the lower electrode plate (7) are subjected to voltage signals through the power amplifier (10). The potential difference between the upper electrode plate (3) and the lower electrode plate (7) attracts or repels the composite electret film (5) with net charge characteristics, thereby achieving the output of the deflection angle. Since the attraction or repulsion force is an electrostatic force, the electric field magnitude is adjusted by changing the gap between the upper electrode plate (3) and the lower electrode plate (7), i.e., increasing or decreasing the thickness of the upper gap adjustment plate (4) and the lower gap adjustment plate (6), thereby achieving mechanical adjustment of the electrostatic force magnitude. The purpose is to make the output angle range and electromechanical conversion efficiency of the deflection device adjustable and controllable. At the same time, during sensing, due to the unique net charge retention characteristics of the composite electret film (5), when the composite electret film (5) produces a certain deflection motion, according to the electrostatic induction theory, the electrostatic balance on the upper electrode plate (3) and the lower electrode plate (7) will be broken, and a corresponding charge surge will appear in the sensing and acquisition device (8) connected to the upper electrode plate (3) and the lower electrode plate (7). The measurement of the deflection angle of the composite electret film (5) is completed by detecting the charge surge.

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