A Braille dot display based on surface-structured PVC gel

Abstract

The present application relates to a kind of braille point display based on surface structured PVC gel, belong to the technical field of application of intelligent material.By casting method, PVC gel with surface array structure is prepared, combined with copper foil electrode to form PVC gel flexible driver;Braille point display includes base, upper cover, 6 PVC gel flexible driver, 6 push rod, 6 spring;Under the action of voltage signal, PVC gel flexible driver cooperates with spring, and pushes push rod to stretch and retract along axial direction, push rod is protruded or withdrawn relative to upper cover;According to braille point display design specification, 6 push rods are arranged according to 3 rows and 2 columns, push rod is protruded or withdrawn by different driver, different braille characters are displayed, and n braille point displays are combined in rows and columns, to provide portable electronic reading equipment for visually impaired people.

Description

Technical Field

[0001] This invention belongs to the field of smart material application technology, specifically a Braille dot display based on surface-structured PVC gel. Background Technology

[0002] A Braille display is a human-computer interaction device that dynamically displays Braille characters. Multiple displays arranged in an array can display complete Braille information, forming a "Braille Kindle" for visually impaired individuals to access knowledge. Based on the driving principle of the actuator, existing Braille displays are broadly classified into electromagnetic, pneumatic, and piezoelectric types. They often suffer from problems such as heavy weight, complex structure, and difficulty in driving. Therefore, research into miniaturization and lightweighting of existing Braille displays urgently requires a new solution.

[0003] PVC gel is an electronically active polymer material and is considered a promising artificial muscle material, attracting widespread attention in the field of intelligent actuators. To design a lightweight, simple, and easily actuated PVC gel actuator, researchers constructed a sandwich structure consisting of a wire mesh anode, PVC gel, and a copper foil cathode. When the electrodes are energized, the gel creeps into the wire mesh under the influence of the electric field, reducing the distance between the anode and cathode. Through multi-layer stacking, a flexible PVC gel actuator capable of outputting linear displacement was fabricated. (Wang, Z., et al., 3D Printing of Electrically Responsive PVC Gel Actuators. ACS Appl Mater Interfaces, 2021.13(20):p.24164-24172.) However, the wire mesh electrode suffers from high stiffness and heavy weight, which are detrimental to the adaptability and lightweight design of the PVC gel actuator. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this invention designs a PVC gel with a surface structure based on the characteristics of PVC gel creeping in an electric field, which gets rid of the constraints of steel wire mesh electrodes, and the corresponding actuator is lighter and more flexible.

[0005] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A Braille dot display based on surface-structured PVC gel includes a push rod 3 and a PVC gel flexible actuator 5. One end of the push rod 3 is connected to the surface electrode of the PVC gel flexible actuator 5. The PVC gel flexible actuator 5 includes surface-structured PVC gel 5-2 and copper foil electrode 5-1. The PVC gel flexible actuator 5 is stacked in multiple layers in the order of "copper foil electrode 5-1 cathode - surface-structured PVC gel 5-2 - copper foil electrode 5-1 anode - structured PVC gel 5-2 - copper foil electrode 5-1 cathode...". When the electrodes are energized, the PVC gel array structure undergoes significant deformation under the action of the electric field, the distance between the electrodes decreases, the actuator shrinks as a whole, and when the power is turned off, the actuator returns to its original shape.

[0007] Preferably, the surface-structured PVC gel 5-2 includes a PVC gel base layer 5-2-1 and a PVC gel surface array 5-2-2, with the copper foil electrode 5-1 anode in contact with the side containing the PVC gel surface array, and the copper foil electrode 5-1 cathode in contact with the side of the PVC gel base layer.

[0008] Preferably, the push rod 3 is divided into an upper push rod end 3-1 and a lower push rod end 3-2. The lower push rod end 3-2 is a flat plate, which is fixed to the uppermost electrode of the PVC gel flexible actuator 5 by industrial glue. The end of the upper push rod end 3-1 is a spherical surface. The push rod moves up and down with the PVC gel flexible actuator. When the PVC gel flexible actuator 5 contracts / recovers its shape, the push rod moves downward / upward along its axis as a follower.

[0009] Preferably, the Braille indicator also includes an upper cover 1 and a base 2, wherein the upper cover 1 and the base 2 cooperate to form the encapsulation of the Braille indicator; the lower end 3-2 of the push rod and the PVC gel flexible actuator 5 are placed together in the encapsulation, and the upper end 3-1 of the push rod extends out of the encapsulation.

[0010] Preferably, the Braille indicator also includes a spring 4, which is wound around the push rod 3 and coaxial with the push rod 3. One end of the spring 4 is fixed to the spring lug 1-3 on the inner side of the upper cover 1, and the other end is fixed to the spring lug 3-3 on the lower end surface of the push rod. When the Braille indicator is not working, the spring 4 is in its natural state.

[0011] Preferably, the upper cover 1 has a through-hole 1-1 for clearance fitting with the upper end 3-1 of the push rod. The push rod hole 1-1 is used to restrict the push rod's forward, backward, left, and right movement and rotation at any angle. The inner side of the upper cover 1 is provided with a spring lug 1-3 for fixing the upper end of the spring 4. The upper cover 1 is provided with a limiting groove 1-2 for fixing the PVC gel flexible actuator. The base 2 is provided with a limiting block 2-2, and the limiting groove 1-2 and the limiting block 2-2 are clearance fitted to fix the upper cover 1 and the base 2 to each other.

[0012] Preferably, the driver limiting grooves 2-1 on the base 2 are arranged in rows and columns, and the lowest electrode of the PVC gel flexible driver 5 is fixed in the limiting groove 2-1; the base 2 is provided with wire holes 2-3 to provide a channel for the power line of the driver, and further connects to the power source through the wire groove 2-4.

[0013] Preferably, the surface-structured PVC gel 5-2 consists of a PVC gel base layer 5-2-1 and a PVC gel surface array 5-2-2. Its preparation process includes PVC gel solution preparation, PVC gel solution casting, vacuuming, natural solvent evaporation, and demolding. Specifically, the process is as follows: PVC powder, plasticizer reagent, and tetrahydrofuran reagent are mixed in a 1:9:15 ratio and thoroughly stirred on a magnetic stirrer until transparent; the stirred transparent solution is cast into a Teflon petri dish with arrayed grooves and treated in a vacuum drying oven for a period of time to remove air bubbles remaining in the solution during casting; the petri dish is then transferred to a fume hood to evaporate the tetrahydrofuran solvent; after the tetrahydrofuran has completely evaporated, the surface-structured PVC gel is removed from the mold.

[0014] This invention also discloses a method for operating a Braille dot display based on surface-structured PVC gel. When the PVC gel flexible actuator is powered on, the actuator retracts, compressing the spring 4. When the power is turned off, the actuator and spring return to their original positions. As a driven component, the push rod 3 moves up and down with the PVC gel flexible actuator. In the initial state, all push rods 3 protrude a certain distance from the upper cover 1. When some actuators are powered on, the corresponding push rods descend below the surface of the upper cover 1, and the remaining push rods display Braille characters, which the reader touches to read.

[0015] Beneficial effects:

[0016] The surface-structured PVC gel involved in this invention eliminates the constraints of wire mesh electrodes, resulting in lighter and more flexible actuators. Compared to electromagnetic, pneumatic, and piezoelectric Braille displays, the surface-structured PVC gel-based Braille display has advantages such as lighter weight, smaller size, and simpler operation, providing a portable and efficient learning tool for visually impaired individuals. Attached Figure Description

[0017] Figure 1 (a) is a cross-sectional view of a Braille dot display according to an embodiment of the present invention;

[0018] Figure 1 (b) is a left view of a Braille dot display according to an embodiment of the present invention;

[0019] Figure 1 (c) is a top view of a Braille dot display according to an embodiment of the present invention;

[0020] Figure 1 (d) is an overall assembly diagram of a Braille dot display according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the base according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a combination of multiple Braille dot displays according to an embodiment of the present invention;

[0023] Figure 4 This is an assembly diagram of a push rod and its driving component according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a PVC gel flexible actuator according to an embodiment of the present invention.

[0025] Figure label:

[0026] 1. Top cover, 1-1. Push rod hole, 1-2. Limiting groove, 1-3. Spring hanger, 2. Base, 2-1. Driver positioning groove, 2-2. Limiting block, 2-3. Wire hole, 2-4. Wire groove, 3. Push rod, 3-1. Upper end of push rod, 3-2. Lower end of push rod, 3-3. Spring hanger, 4. Spring, 5. PVC gel flexible driver, 5-1. Copper foil electrode, 5-2. Surface structured PVC gel, 5-2-1. PVC gel base layer, 5-2-2. PVC gel surface array. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Based on the characteristics of PVC gel creeping in an electric field, this invention designs a PVC gel with a surface structure and combines it with copper foil anode and cathode electrodes to prepare a novel PVC gel flexible actuator, which is used as a micro actuator for a Braille dot display, providing a convenient reading tool for visually impaired people.

[0029] like Figure 1 (a) to Figure 1 As shown in (d), the PVC gel-based Braille display includes a top cover 1, a base 2, a push rod 3, a spring 4, and a PVC gel flexible actuator 5. The top cover 1 and base 5 cooperate to form the overall package of the Braille display. The PVC gel flexible actuator 5 is connected to the push rod 3, and the spring 4 is wound around the push rod 3. The PVC gel flexible actuator 5, spring 4, and the lower end 3-2 of the push rod are placed inside the package. The upper end 3-1 of the push rod extends out of or is hidden within the top cover 1 depending on the movement of the PVC gel flexible actuator 5. When the PVC gel flexible actuator is powered on, the actuator retracts, compressing the spring 4. When the power is turned off, the actuator 5 and spring 4 return to their original positions. As a driven component, the push rod 3 moves up and down with the PVC gel flexible actuator. Initially, all push rods 3 protrude a certain distance from the top cover 1. When some actuators are powered on, the corresponding push rods descend below the surface of the top cover 1, while the remaining push rods display Braille characters for the reader to touch and read.

[0030] Traditional PVC gel actuators consist of a wire mesh anode, a copper foil cathode, and sheet-like PVC gel, arranged in a multi-layered manner: "copper foil cathode - sheet-like PVC gel - wire mesh anode - sheet-like PVC gel - copper foil cathode...". When the electrodes are energized, a portion of the sheet-like gel's volume creeps into the wire mesh under the influence of the electric field, reducing the distance between the electrodes. When the power is turned off, the gel returns to its original shape, and the distance between the electrodes is restored.

[0031] The PVC gel flexible actuator 5 of the present invention includes a surface-structured PVC gel 5-2 and a copper foil electrode 5-1. The surface-structured PVC gel 5-2 includes a PVC gel base layer 5-2-1 and a PVC gel surface array 5-2-2. The PVC gel flexible actuator 5 achieves multi-layer stacking in the order of "copper foil cathode - surface-structured PVC gel - copper foil anode - surface-structured PVC gel - copper foil cathode...". The copper foil anode is in contact with the side with the PVC gel surface array 5-2-2, and the copper foil cathode is in contact with the side with the PVC gel base layer 5-2-1. When the electrodes are energized, the PVC gel array structure undergoes significant deformation under the action of the electric field force, the distance between the electrodes decreases, the actuator shrinks as a whole, and when the power is turned off, the actuator returns to its original shape.

[0032] The push rod 3 is divided into an upper push rod end 3-1 and a lower push rod end 3-2. The end of the upper push rod end 3-1 is spherical to ensure a good tactile feel when touched by the reader; the lower push rod end 3-2 is a large flat plate to ensure the largest possible contact area with the PVC gel flexible actuator 5. The lower push rod end 3-2 is provided with a spring lug 3-3. In this embodiment, according to the design requirements of the Braille display, the contact point at the end of the upper push rod is spherical, and the lower push rod end is a semi-circular flat plate. It is fixed to the uppermost electrode of the PVC gel actuator with industrial glue. When the gel shrinks, the push rod can move downward along the axial direction of the PVC gel flexible actuator as a driven member.

[0033] Spring 4 is coaxial with push rod 3, with one end fixed to spring lug 1-3 on the inside of upper cover 1, and the other end fixed to spring lug 3-3 on the lower end 3-2 of push rod. When the Braille display is not working, the spring is in its natural state.

[0034] The upper cover 1 and the base 2 together form the enclosure of the Braille indicator. In this embodiment, the upper cover 1 is provided with 6 push rod holes 1-1 and 6 spring lugs 1-3; the base 2 is provided with 6 driver limiting slots 2-1 and 9 wire holes 2-3. The push rod holes 1-1 are used to limit the push rod's forward, backward, left, and right movement and rotation at any angle; the spring lugs 1-3 are used to fix one end of the spring 4; the driver limiting slots 2-1 are used to fix the PVC gel flexible driver; the wire holes 2-3 provide a channel for the driver power line and further connect to the power supply through the wire slots 2-4. In addition, the limiting slots 1-2 on the upper cover 1 and the limiting blocks 2-2 on the base 2 are clearance-fitted to fix the upper cover 1 and the base 2 to each other. The base structure is as follows. Figure 2 As shown.

[0035] According to Braille display design specifications, six actuators are arranged in a 3x2 grid. Different actuators push the actuators up or down to display different Braille characters. Multiple Braille displays arranged in an array constitute a Braille display. Combinations of different Braille characters can provide Braille information to the reader, such as… Figure 3 As shown.

[0036] like Figure 4 As shown, the upper end of the push rod of the Braille indicator is the contact point, which contacts the reader's fingertip. The lower end of the push rod is bonded to a PVC gel flexible actuator. When the actuator undergoes linear deformation, the push rod moves up and down as a driven component. The spring is coaxial with the push rod, with one end fixed to the inside of the top cover and the other end fixed to the lower end of the push rod. When the Braille indicator is not working, the PVC gel flexible actuator is in its natural state, and the spring is also in its natural state. When some contacts of the Braille indicator are working, the corresponding PVC gel flexible actuator contracts and deforms, and the spring is stretched.

[0037] like Figure 5As shown, the PVC gel flexible actuator includes a multilayer surface-structured PVC gel 5 and a copper foil electrode 5-1. One side of the prepared surface-structured PVC gel is flat, while the other side has a regular array structure. During actuator assembly, the side with the array structure contacts the anode, and the flat side contacts the cathode. Multiple layers can be stacked according to the actuation requirements.

[0038] The casting process for preparing surface-structured PVC gel in this invention includes PVC gel solution preparation, PVC gel solution casting, vacuuming, natural solvent evaporation, and demolding. Specifically: 1) A certain amount of PVC powder, plasticizer reagent, and tetrahydrofuran reagent are mixed in a mass ratio of 1:9:15 and stirred thoroughly with a magnetic stirrer until transparent; 2) The stirred transparent solution is cast into a Teflon petri dish with arrayed grooves and treated in a vacuum drying oven for a period of time to remove air bubbles remaining in the solution during the casting process; the petri dish is then transferred to a fume hood to evaporate the solvent (tetrahydrofuran); 3) After the tetrahydrofuran has completely evaporated, the PVC gel with surface structure is removed from the mold.

[0039] This invention also discloses a working method for a Braille dot display based on surface-structured PVC gel. When the PVC gel flexible actuator electrode 5 is energized, the actuator retracts, and the push rod 3 descends automatically. The upper end 3-1 of the push rod is hidden in the push rod hole 1-1 of the upper cover 1, so the reader cannot touch the contact point when reading. When the power is turned off, the push rod 3 returns to its initial position under the combined action of the spring 4 and the flexible actuator 5, and the contact point is exposed. By changing the combination of several actuator power signals, different Braille characters are displayed to the reader.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A Braille dot display based on surface-structured PVC gel, characterized in that, It includes a push rod (3) and a PVC gel flexible actuator (5), one end of which is connected to the surface electrode of the PVC gel flexible actuator (5); The PVC gel flexible actuator (5) includes a surface-structured PVC gel (5-2) and a copper foil electrode (5-1). The PVC gel flexible actuator (5) is arranged in one or more groups in the order of "copper foil electrode (5-1) cathode - surface-structured PVC gel (5-2) - copper foil electrode (5-1) anode - structured PVC gel (5-2)". The surface-structured PVC gel (5-2) includes a PVC gel base layer (5-2-1) and a PVC gel surface array (5-2-2). The anode of the copper foil electrode (5-1) is in contact with the side with the PVC gel surface array, and the cathode of the copper foil electrode (5-1) is in contact with the side with the PVC gel base layer. When the electrode is energized, the PVC gel surface array (5-2-2) undergoes obvious linear deformation under the action of the electric field force, the distance between the electrodes decreases, and the PVC gel flexible actuator (5) shrinks as a whole. When the power is turned off, the actuator returns to its original shape.

2. The Braille dot display based on surface-structured PVC gel according to claim 1, characterized in that, The push rod (3) is divided into an upper end (3-1) and a lower end (3-2). The lower end (3-2) is a flat plate, which is fixed to the uppermost electrode of the PVC gel flexible actuator (5). The end of the upper end (3-1) is a spherical surface. When the PVC gel flexible actuator (5) contracts / recovers its shape, the push rod moves downward / upward along its axis as a follower.

3. The Braille dot display based on surface-structured PVC gel according to claim 1, characterized in that, The Braille display also includes an upper cover (1) and a base (2). The upper cover (1) and the base (2) cooperate to form the package of the Braille display. The lower end (3-2) of the push rod and the PVC gel flexible actuator (5) are placed in the package, and the upper end (3-1) of the push rod extends out of the package.

4. The Braille dot display based on surface-structured PVC gel according to claim 3, characterized in that, The Braille indicator also includes a spring (4), which is wrapped around the push rod (3) and is coaxial with the push rod (3). One end of the spring (4) is fixed to the inside of the upper cover (1), and the other end is fixed to the lower surface of the push rod. When the Braille indicator is not working, the spring (4) is in its natural state.

5. The Braille dot display based on surface-structured PVC gel according to claim 3, characterized in that, The upper cover (1) is provided with a push rod hole (1-1) through it, which is in clearance fit with the upper end (3-1) of the push rod; the inner side of the upper cover (1) is provided with a spring lug (1-3) for fixing the upper end of the spring (4); the upper cover (1) is provided with a limiting groove (1-2), and the base (2) is provided with a limiting block (2-2). The limiting groove (1-2) and the limiting block (2-2) are in clearance fit so that the upper cover (1) and the base (2) are fixed to each other.

6. The Braille dot display based on surface-structured PVC gel according to claim 3, characterized in that, The driver limiting grooves (2-1) on the base (2) are arranged in rows and columns, and the bottom electrode of the PVC gel flexible driver (5) is fixed in the driver limiting groove (2-1); the base (2) is provided with wire holes (2-3) to provide a channel for the power line of the driver, and further connects to the power supply through the wire groove (2-4).

7. The Braille dot display based on surface-structured PVC gel according to claim 1, characterized in that, The surface-structured PVC gel was prepared using a solution casting method. The specific preparation process of the surface-structured PVC gel is as follows: PVC powder, plasticizer reagent, and tetrahydrofuran reagent are mixed at a mass ratio of 1:9 and stirred thoroughly; the stirred solution is cast into a Teflon petri dish with an array of grooves and vacuum-treated using a vacuum drying oven; the PVC gel solution is transferred to a fume hood to allow the tetrahydrofuran in the solution to completely evaporate; after the tetrahydrofuran has evaporated, the gel is demolded.

8. The Braille dot display based on surface-structured PVC gel according to claim 1, characterized in that, When the electrodes of the PVC gel flexible actuator (5) are energized, the PVC gel is subjected to electric field force, the array structure deforms, the distance between the electrodes decreases, the PVC gel flexible actuator (5) shrinks as a whole, the power supply is cut off, and the actuator returns to its original shape.

9. A method for operating a Braille dot display based on surface-structured PVC gel, characterized in that, Based on the Braille dot display according to any one of claims 1 to 8, when the electrode of the PVC gel flexible actuator (5) is energized, the actuator retracts, the push rod (3) descends automatically, and the upper end (3-1) of the push rod is hidden in the push rod hole (1-1) of the upper cover (1), so that the reader cannot touch the contact point when reading; When the power is cut off, the push rod (3) returns to its initial position under the combined action of the spring (4) and the PVC gel flexible actuator (5), and the contacts are exposed; by changing the combination of power on and off of several actuator power signals, different Braille characters are displayed to the reader.

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