Origami-based contact members, devices and systems for active mechanical haptics

Abstract

The invention relates to origami-based contact members, devices and systems for active mechanical haptics. The origami-based contact member for active mechanical haptics includes: a top plate; a bottom plate; the metamaterial is arranged between the top plate and the bottom plate, the top end of the metamaterial is fixed on the top plate, the bottom end of the metamaterial is fixed on the bottom plate, the top plate is exposed outside so as to be in contact with a body part of a user, the metamaterial based on the curved-surface folded paper comprises a panel, the panel is provided with a single curved-surface fold extending in the longitudinal direction of the panel, and the single curved-surface fold extends along the longitudinal direction of the panel. And the panel is divided into two surfaces on two opposite sides by the single curved surface crease. The panel is configured to fold along a single curved fold to form a fold angle between the two faces. The folding angle is configured to be adjusted by rotating the base plate so as to achieve a variable stiffness encompassing positive to negative stiffness when loaded along a vertical axis between the top plate and the base plate, the variable stiffness to be perceived by a body part of a user via contact with the top plate.

Description

Technical Field

[0001] The present disclosure relates to origami-based contact members, devices, and systems for active mechanical haptics. Background Art

[0002] The emerging metaverse driven by virtual reality (VR) and augmented reality (AR) technologies is transforming current digital media from a third-person perspective into a future immersive platform that vividly presents the physical environment perceived from a first-person perspective. This is achieved by constructing virtual environments with realistic sensory perceptions, including but not limited to vision, hearing, and touch. In this new paradigm of how humans interact with future media, VR / AR technology is ready to penetrate a range of industry sectors (e.g., entertainment, communications, education, human-computer interaction, teleoperation, clinical treatment, and rehabilitation), while enhancing our VR / AR, tactile experience with the help of advanced software (i.e., communications technology, various applications, and social networks) and hardware (i.e., VR / AR and tactile devices). Although the latest VR / AR devices provide stereoscopic visual and auditory sensory perceptions, they cannot convey a specific sensory dimension (i.e., touch) in the mechanical realm. In fact, touch is very different from our vision and hearing, which are passive because we humans receive information in the third person. Substantial progress has been made in making virtual worlds tactile by giving users a passive haptic experience; however, most produce simple, hand-centric motion constraints or vibrations (vibrotactile haptics). This is in stark contrast to the physical environment where humans feel the hardness, softness, and even the breaking moment of fragile objects through active touch with their hands, feet, or other body parts. On the other hand, touch is primarily active, and human-triggered mechanosensory perception is considered one of the most indispensable human senses for interacting with the physical world. Therefore, it is promising to reproduce controlled active mechano-tactile haptics in virtual worlds that allow users to actively generate and perceive mechano-tactile haptics. Summary of the invention

[0003] The present disclosure is provided to solve the above-mentioned problems existing in the prior art, namely, to provide an origami-based contact member and a tactile device for active mechanical tactile, an immersive VR / AR system for providing active mechanical tactile, and corresponding sensory perception, thereby allowing a user to actively generate and perceive mechanical tactile sensations with controllable stiffness ranging from hard to soft and from positive to negative. The origami-based contact member, tactile device, and immersive VR / AR system are intended to generate human-triggered mechanical sensory perceptions and enhance VR / AR experiences in addition to vision, hearing, or passive tactile sensations, while providing a range of diverse immersive experiences.

[0004] According to one embodiment of the present disclosure, an origami-based contact member for active mechanical haptics comprises: a top plate; a bottom plate; and at least one piece of curved origami-based metamaterial placed between the top plate and the bottom plate, with its top end fixed on the top plate and its bottom end fixed on the bottom plate, the top plate being exposed to be contacted by a body part of a user; wherein the curved origami-based metamaterial comprises a panel having a single curved crease extending along its longitudinal direction, the single curved crease dividing the panel into two surfaces on opposite sides thereof, the panel being constructed to be folded along the single curved crease to form a folding angle between the two surfaces; the folding angle being constructed to be adjusted by rotating the bottom plate so as to achieve a variable stiffness ranging from positive stiffness to negative stiffness when loaded along a vertical axis between the top plate and the bottom plate, the variable stiffness being sensed by a body part of the user via contact with the top plate.

[0005] In another embodiment of the present disclosure, a tactile handheld device for providing active mechanical tactile sensation is provided, the device comprising: five origami-based contact members according to any embodiment of the present disclosure, the user's body part is a finger or a thumb; an actuation mechanism and a control unit, wherein the control unit is configured to: communicate with a VR / AR engine to receive a stiffness adjustment command indicating a current stiffness of the virtual object while tracking the user's active grasping operation on the virtual object in the VR / AR scene; and control the actuation mechanism in response to the stiffness adjustment command to rotate the axis of the bottom plate to adjust the stiffness to be sensed by the user's finger / thumb; and a support shell for accommodating the five origami-based contact members, the actuation mechanism and the control unit, the support shell being provided with five openings for exposing the top plate to the outside.

[0006] In another embodiment of the present disclosure, an origami-based contact member for active mechanical haptics is provided, the contact member comprising: a top plate, which is exposed to the outside to be contacted by a body part of a user; a bottom plate; a plurality of pieces of curved origami-based metamaterials, placed between the top plate and the bottom plate and arranged in a plurality of rows; and cables, the cables being arranged corresponding to the rows so that each row has an independent cable; each piece of curved origami-based metamaterial has a top end and a bottom end, the top end is fixed to the top plate, and the bottom end is fixed to the bottom plate; each piece of curved origami-based metamaterial comprises a panel having a single curved fold extending along its longitudinal direction, the single curved fold connecting the panel at its relative positions. The two sides of the pair are divided into two surfaces, and the panel is constructed to be folded along a single curved crease to form a folding angle between the two surfaces; a first hole is formed on one of the two surfaces, and a second hole is formed on the other of the two surfaces; for each row of multiple pieces of curved origami-based metamaterials, corresponding independent cables are sequentially passed through the two holes cut on the panel, and are knotted on one side behind each panel so as to be synchronously pulled / released to adjust the folding angle of the panel, so that when loaded along the vertical axis between the top plate and the bottom plate, a variable stiffness covering a range from positive stiffness to negative stiffness is achieved, and the variable stiffness will be sensed by the user's body parts via contact with the top plate.

[0007] In another embodiment of the present disclosure, a tactile pedaling device for providing active mechanical tactile sensation is provided, the device comprising: an origami-based contact member according to any embodiment of the present disclosure, wherein the user's body part is a foot; and an actuation mechanism comprising a cable and a control unit, wherein the control unit is configured to: communicate with a VR / AR engine to receive a stiffness adjustment command indicating the current stiffness of the virtual object while tracking the user's active pedaling operation on the virtual object in the VR / AR scene; and control the actuation mechanism in response to the stiffness adjustment command to synchronously pull / release the cable to adjust the stiffness to be sensed by the user's foot.

[0008] In another embodiment of the present disclosure, an immersive VR / AR system for providing active mechanical tactile sensation is provided, the system comprising: a tactile handheld device for providing active mechanical tactile sensation according to any embodiment of the present disclosure and / or a tactile treading device for providing active mechanical tactile sensation according to any embodiment of the present disclosure, as a tactile component; and a VR / AR engine, which is configured to: communicate with both the VR / AR device and the tactile device; send a stiffness adjustment command indicating the current stiffness of the virtual object to the tactile component when tracking the user's active grasping and / or active treading operation on the virtual object in the VR / AR scene; and send a stream related to the VR / AR scene to the VR / AR device. The immersive VR / AR system also includes a VR / AR device, which is configured to: communicate with the VR / AR engine to receive a stream related to the VR / AR scene and present the VR / AR scene to the user accordingly; and track the user's active grasping and / or active treading operation on the virtual object in the VR / AR scene.

[0009] In another embodiment of the present disclosure, an origami-based contact member for active mechanical haptics is provided, comprising: a top plate; a bottom plate; and at least one piece of curved origami-based metamaterial disposed between the top plate and the bottom plate, wherein the curved origami-based metamaterial comprises a panel, and variable stiffness of the curved origami-based metamaterial is achieved by twisting the panel or pulling / releasing the panel by a connecting member passing through the panel; wherein the variable stiffness covers a range from positive stiffness to negative stiffness.

[0010] Other details and aspects of exemplary embodiments of the present disclosure are described in more detail below in conjunction with the accompanying drawings.

[0011] The origami-based contact member and tactile device for active mechanical haptics according to the present disclosure can realize active mechanical haptics covering positive stiffness (feeling hard and soft) and negative stiffness (feeling broken and falling moments), which are considered to be the core and part of the first sensory perception in the daily interaction between humans and the physical environment for exploring / processing information and creating ontological metaphors. In addition, the immersive VR / AR system for providing active mechanical haptics according to the present disclosure can obtain a combination of visual, auditory and active touch sensory perceptions in the AR / VR tactile experience, thereby providing exciting potential for expanding the reality of the virtual world.

[0012] The foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to restrict the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. Similar reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the disclosed embodiments. These embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present method, apparatus, system, or non-transitory computer-readable medium having instructions thereon for implementing the method.

[0014] FIG. 1( a ) and FIG. 1( b ) illustrate several exemplary active stiffness perceptions in life scenarios according to an embodiment of the present disclosure.

[0015] FIG. 2( a ) illustrates a schematic diagram of partial composition of an origami-based contact member for active mechanical haptics according to an embodiment of the present disclosure.

[0016] FIG. 2( b ) illustrates a schematic diagram of two symmetrically arranged curved origami-based metamaterials according to an embodiment of the present disclosure.

[0017] Figure 3(a) to Figure 3(h) The figure shows a schematic diagram of the partial composition of a metamaterial based on curved origami and the working mechanism of its stiffness adjustment according to an embodiment of the present disclosure.

[0018] Figure 4 Figure illustrates an example diagram of a button formed by origami-based contact members according to an embodiment of the present disclosure.

[0019] Figure 5 The figure shows the construction of a single curved crease according to an embodiment of the present disclosure.

[0020] FIG. 6( a ) schematically illustrates a process of manufacturing a substrate with a silver nanowire (AgNW) coating deposited thereon for a panel.

[0021] FIG6( b ) illustrates the relative resistance change (ΔR / R0) of the sensing layer when strain is applied at different folding angles.

[0022] FIG. 7( a ) illustrates an example diagram of a user using a haptic handheld device to perceive different stiffnesses of various objects in a virtual environment according to an embodiment of the present disclosure.

[0023] FIG. 7( b ) illustrates a schematic diagram of partial components of a tactile handheld device according to an embodiment of the present disclosure.

[0024] FIG7( c ) illustrates a confusion matrix showing the recognition rates of the 12 participants under three different interaction methods.

[0025] FIG7( d ) illustrates the physiological signals (EMG) of the upper limbs when the user grasps different real objects and virtual objects under three holding conditions.

[0026] Figure 8 FIG. 1 is a schematic diagram showing a partial composition of a control unit of a tactile handheld device according to an embodiment of the present disclosure.

[0027] FIG. 9( a ) illustrates an exploded schematic diagram of an actuation mechanism of a haptic handheld device according to an embodiment of the present disclosure.

[0028] FIG9( b ) illustrates a schematic top view of a transmission system of an actuating mechanism according to an embodiment of the present disclosure.

[0029] FIG. 10( a ) illustrates a schematic diagram of the composition of another origami-based contact member for active mechanical haptics according to an embodiment of the present disclosure.

[0030] FIG. 10( b ) illustrates a schematic diagram of a curved origami-based metamaterial according to the origami-based contact member of FIG. 10( a ).

[0031] Fig.11 The figure shows a schematic diagram of a tread member formed by an origami-based contact member according to an embodiment of the present disclosure.

[0032] Fig.12 FIG. 2 is a schematic diagram showing a partial composition of a control unit of a tactile pedaling device according to an embodiment of the present disclosure.

[0033] FIG. 13( a ) illustrates an exploded schematic diagram of an actuation mechanism of a tactile pedaling device according to an embodiment of the present disclosure.

[0034] Figure 13(b) to Figure 13(d) The figure shows a schematic diagram of a transmission system and synchronous actuation of an actuation mechanism of a metamaterial based on curved origami according to an embodiment of the present disclosure.

[0035] Fig.14 The figure shows a schematic diagram of partial composition of an immersive VR / AR system for providing active mechanical tactile sensation according to an embodiment of the present disclosure.

[0036] FIG. 15 illustrates a schematic diagram of partial composition of another origami-based contact member for active mechanical haptics according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure will be described in detail below in conjunction with the drawings and specific embodiments. The embodiments of the present disclosure will be described in more detail below in conjunction with the drawings and specific embodiments, but these embodiments are not intended to limit the present disclosure.

[0038] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprising" and other similar words mean that the elements appearing before the word include the elements listed after the word, but do not exclude other elements.

[0039] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on the present disclosure with equivalent elements, modifications, omissions, combinations (e.g., scenarios associated with various embodiments), modifications or changes. The elements of the claims should be broadly interpreted based on the language adopted in the claims, and these elements are not limited to the examples described in this specification or in the implementation of this application, and the examples should be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered as examples only, and the true scope and spirit are represented by the full scope of the attached claims and their equivalents.

[0040] FIG1(a) and FIG1(b) illustrate several exemplary active stiffness perceptions in life scenarios according to an embodiment of the present disclosure. In FIG1(a), an example of manually initiated handheld stiffness perception is shown, including: positive stiffness is felt when grasping elastic / rigid / soft objects, and negative stiffness is felt when crushing fragile objects (such as eggs). And, in FIG1(b), an example of manually initiated body-centered stiffness perception is schematically illustrated, including: positive stiffness is felt during stepping on various surfaces, and negative stiffness is felt when accidentally stepping on air.

[0041] In the scenes shown in FIG. 1( a) and FIG. 1( b), when an object is grasped in the hand or stepped on, people can easily distinguish the object due to its unique inherent properties (i.e., its stiffness). When hitting a ball or stepping on a ground of different hardness, the human body feels positive stiffness, and this difference is reflected in the magnitude of the positive stiffness value. However, when crushing an egg or stepping on air while walking, negative stiffness is experienced, resulting in a feeling of falling or even fear (the heart rate curve in FIG. 1( b) shows the user's psychological reaction). In order to recreate these active tactile sensations in a VR / AR environment, an origami-based contact member, a tactile device, and an immersive VR / AR system for active mechanical tactile sensations are proposed in the present disclosure.

[0042] FIG. 2( a ) illustrates a schematic diagram of partial composition of an origami-based contact member for active mechanical haptics according to an embodiment of the present disclosure.

[0043] As shown in FIG2(a), the origami-based contact member for active mechanical haptics includes a top plate 21, a bottom plate 22, and at least one piece of curved origami-based metamaterial 23 therebetween (with its top end 23a fixed on the top plate 21 and its bottom end 203b fixed on the bottom plate 22), wherein the top plate 21 is exposed to be contacted by a body part of a user (not shown in FIG2(a)).

[0044] Figure 3(a) to Figure 3(h) The figure shows a schematic diagram of the partial composition of the metamaterial 23 based on curved origami and the working mechanism of its stiffness adjustment. In these figures, α (the angle between the horizontal edge and the tangent line at the end of a single curved crease 232) represents the normalized curvature of the single curved crease 232; α (the angle between two curved surfaces (surface 1 and surface 2)) represents the plastic origami folding.

[0045] FIG3( a) shows a 2D style (unfolded) and a 3D structure (already folded) of a metamaterial 23 based on curved origami. As shown in FIG3( a), the metamaterial 23 based on curved origami includes a panel 231 having a single curved crease 232 extending along its longitudinal direction, which divides the panel 231 into two faces on opposite sides thereof, which are shown as face 1 and face 2. In addition, the panel 231 is configured to be folded along the single curved crease 232 to form a folding angle β between face 1 and face 2, and the folding angle β is configured to be adjusted by rotating the bottom plate 22 so that when loading is applied along the vertical axis between the top plate 21 and the bottom plate 22, a variable stiffness ranging from positive stiffness to negative stiffness is achieved, which will be sensed by a user's body part through contact with the top plate 21 (see FIG2( a)).

[0046] Referring to FIG. 3( a ), by simply introducing a single curved surface crease 232 (the single curved surface crease is a circular arc cutting line characterized by an angle α, and the relationship between the angle α and the radius ρ of the circle is Where a×b is the geometric shape of the rectangular panel 231), the origami-based metamaterial 23 is formed by folding the 2D panel 231 along a single curved crease 232 (Figure 3(a)). The folding angle β around the single curved crease 232 is determined by the plasticity imposed by the folding process, where the greater the bending deformation of the origami-based metamaterial 23, the smaller β, and the smaller the bending deformation, the larger β. For the plasticity at the single curved crease 232, the panel 231, and the single curved crease 232, a variant (non-standard) Miura origami (Figure 3(b)) is used to analyze, simulate, and describe in detail the mechanical properties of the origami, where the angle γ is related to the plastic folding angle β (i.e., γ(β)), which is then used to predict the stiffness of the origami and guide design choices. When a vertical load is applied to the top plate 21 (see FIG. 2( a) ), the origami-based metamaterial 23 exerts different force-displacement relationships according to the competition between the bending deformation providing positive stiffness and the folding deformation around the single curved crease 232 providing negative stiffness. FIG. 3( c) shows the force-displacement relationship of a piece of origami-based metamaterial 23 defined by α=80° and a / b=1.25 at different folding angles β (i.e., initial state) of 60°, 90°, and 120°, where a larger β (e.g., 120°) presents both positive and negative ranges, while a smaller β (e.g., 60°) produces only positive stiffness. Therefore, for a given origami-based metamaterial 23 (i.e., angle α), its stiffness can be easily adjusted by changing the folding angle β (e.g., by rotating the bottom plate 22, or by a cable-actuated approach (Fig. 3(d)), where an external force is actively applied to the top plate 21 (e.g., by a user of active mechanical haptics), and a cable is passed through the two surfaces (surface 1 and surface 2) to adjust the folding angle β in real time by Δβ starting from a specific initial value (e.g., β = 120° for a wider adjustment range). Unlike the plasticity in the folding process that limits the folding angle β, twisting the bottom plate 22 or pulling the cable produces a surface-based origami-based metamaterial. The elastic folding process of the origami metamaterial 23, wherein the metamaterial 23 immediately returns to its original folded state (defined by the folding angle β) after the bottom plate 22 is twisted back or the cable is released. FIG3( e ) shows the force-displacement relationship of the origami-based metamaterial 23 at different adjustment angles Δβ (Δβ = 0°, 35°, and 60°), wherein α = 80°, β = 120°, and a / b = 1.25, when loaded along the vertical axis between the top plate 21 and the bottom plate 22, a variable stiffness covering a positive and negative range is presented, and the variable stiffness can be sensed by the user's body parts through contact with the top plate 21.

[0047] The embodiments described above establish the effectiveness of using a cable-driven approach (including cable-induced torsion) to adjust the stiffness of origami in real time. As for tactile perception, different positive stiffnesses reflect hardness levels, while negative stiffnesses mimic the feeling of crushing an object or falling (or sliding). Therefore, during the process of actively pressing an origami-based metamaterial with negative stiffness with a constant force, its acceleration becomes an important metric to characterize this property. For the same origami-based metamaterial in Figure 3(e), the acceleration of the constant load (i.e., constant force) can be as high as 0.6G (1G in free fall) at β=120° and Δβ=0°, 35°, and 40°, as shown in Figure 3(f). To guide the design of origami-based metamaterials to achieve more pronounced mechanical perception, Figure 3(g) provides a phase diagram of the normalized secant stiffness as a function of the crease angle α (30°<α<85°) and the adjustment angle Δβ, where the initial folding angle β = 120°, i.e., the actual angle when the cable is pulled, ranges from 0° to 120°. In order to utilize the most significant stiffness perception, when the origami has both positive and negative stiffness ranges, only the maximum negative stiffness is selected. When the origami has only a positive stiffness range, the maximum positive stiffness is adopted. From a practical point of view, the angle α is a predetermined parameter because it defines the style of the origami-based metamaterial. For example, to obtain both positive and negative stiffness, the crease angle is set in the range of 55° to 85°, and the folding angle is adjusted between 30° and 130°.

[0048] Therefore, the phase diagram provides a design (via angle α) and operation guide (via adjusting angle Δβ) to obtain stiffness sensory perception using origami-based metamaterials. Similar to the elastic deformation during plate rotation or cable pulling, the deformation during cyclic pressing of the top plate of the origami-based metamaterial is also elastic (Figure 3(h)), where negative and positive stiffness can be clearly seen in each cycle.

[0049] In some embodiments, at least one piece of origami-based metamaterial includes two pieces (e.g., a pair) of origami-based metamaterials. As shown in FIG2( b ), there are two pieces of origami-based metamaterials (i.e., origami-based metamaterial 23 and origami-based metamaterial 23 ′), wherein one piece of origami-based metamaterial is symmetrical with the other piece of origami-based metamaterial along axis 31, thereby providing a more stable structure when used to construct a tactile device.

[0050] In some embodiments, the origami-based contact member according to embodiments of the present disclosure is formed as a button. Figure 4As shown, five buttons (i.e., button 41, button 42, button 43, button 44, and button 45) are each formed by an origami-based contact member according to an embodiment of the present disclosure. In addition, taking button 44 as an example, bottom plate 442 is circular and provided with shaft 442a, which can be rotated by actuating mechanism 46.

[0051] In some embodiments, Figure 4 A single surface crease in an origami-based contact component can have Figure 5 As shown in the structure. Figure 5 As shown, the single curved fold 50 is constructed by the following parts: two end extensions (i.e., end extension 51a and end extension 51b), an intermediate extension 51c and two arc-shaped cutting grooves (i.e., arc-shaped cutting groove 52a and arc-shaped cutting groove 52b), each cutting groove connecting its adjacent end extension and intermediate extension.

[0052] In some embodiments (such as Figure 4 or Figure 5 In the origami-based contact member in the invention, the panel can be made of a substrate deposited with a sensing layer, which is used to sense the loaded strain and change its electrical properties. Figure 6(a) shows a process for manufacturing a substrate deposited with a silver nanowire (AgNW) coating, which is deposited on the substrate of the panel as a sensing layer. Specifically, in step S61, a substrate and an AgNW suspension are prepared. In step S62, the AgNW suspension is coated (applied) to the surface of the substrate. Then, in step S63, the suspension is dried in an oven for 6 hours to obtain an AgNW-coated substrate. In some embodiments, the loaded strain of the panel can be represented by a height change, and the electrical properties of the sensing layer can be represented, for example, by a relative resistance change (ΔR / R0), so the relationship between the sensed loaded strain and the electrical properties of the sensing layer is shown in Figure 6(b).

[0053] Figure 6(b) shows the relative resistance change (ΔR / R0) of the sensing layer when the top plate of the origami-based contact member is cycled and actively pressed at different folding angles (i.e., β-Δβ, where β = 120°, Δβ = 0°, 30°, 60°, and 90°). From Figure 6(b), the characteristics of the change in electrical properties can be observed: the change in relative resistance change (ΔR / R0) is positively correlated with the loading strain.

[0054] According to an embodiment of the present disclosure, a tactile handheld device for providing active mechanical tactile sensation is also provided. FIG. 7( a) shows an example diagram of a user using a tactile handheld device to perceive different stiffnesses of various objects in a virtual environment according to an embodiment of the present disclosure. As shown in FIG. 7( b), the tactile handheld device 700 includes five origami-based contact members according to the present disclosure (origami-based contact members 71a-71e as shown in FIG. 7( b)), and the user's body part is a finger or thumb (for actively grasping the origami-based contact members of the tactile handheld device 700, as shown in FIG. 7( a)).

[0055] In some embodiments, the haptic handheld device 700 may include an actuation mechanism (not shown) and a control unit (not shown). Specifically, the control unit is configured to communicate with a VR / AR engine (not shown in FIG. 7( b)) so as to receive a stiffness adjustment command indicating the current stiffness of a virtual object while tracking an active grasping operation performed by a user on a virtual object in a VR / AR scene, wherein the virtual object in the VR / AR scene corresponds to the haptic handheld device 700. The control unit is also configured to control the actuation mechanism in response to the stiffness adjustment command so as to rotate the axis of the bottom plate of the origami-based contact members 71a-71e forming the button to adjust the stiffness perceived by the user's finger / thumb. In addition, the haptic handheld device 700 also includes a support shell 74 for accommodating five origami-based contact members, the actuation mechanism, and the control unit, and the support shell 74 is provided with five openings for exposing the top plate of the origami-based contact members to the outside.

[0056] As shown in Figure 7(b), the support shell 74 is spherical in shape and has five narrow grooves 741 for respectively accommodating five origami-based contact members 71a-71e, and each narrow groove 741 is provided with a sliding guide portion 741a for limiting the compression range (for example, 10 mm) of the corresponding origami-based contact member.

[0057] Furthermore, five origami-based contact members may be mounted in the support case 74 according to a common human gripping posture, with the origami-based contact member 71 e for the thumb being located on a side of the support case 74 opposite to that of the other four fingers.

[0058] like Figure 8 As shown, the control unit of the tactile handheld device 700 according to an embodiment of the present disclosure may further include a microcontroller 731, a sampling resistor module 732, and a wireless communication interface 733. In some embodiments, the sensing layer is configured to change its resistance (e.g., Figure 8In some other embodiments, the sampling resistor module 732 is connected to the sensing layer and converts its changed resistance R into a voltage change.

[0059] In some other embodiments, the microcontroller 731 is connected to the sampling resistor module 732 and forwards the voltage change to the VR / AR engine 75 via the wireless communication interface 733, so that the VR / AR engine 75 then converts the voltage change into a deformation of the virtual object and changes the corresponding VR / AR scene that the user will see through the VR / AR device 76. In addition, a power supply 77 (such as a small 5V battery) can be integrated into the support shell 74 to achieve wireless control.

[0060] FIG9( a) illustrates an exploded schematic diagram of an actuation mechanism of a tactile handheld device according to an embodiment of the present disclosure. In some other embodiments, the control unit of the tactile handheld device 700 may further include a motor drive module 734, and accordingly, the actuation mechanism further includes a motor 721 and a transmission system 722, as shown in FIG9( a) and FIG9( b).

[0061] Figure 8 The microcontroller 731 in the haptic handheld device may also be configured to receive a stiffness adjustment command indicating the changed stiffness of the virtual object (not shown) from the VR / AR engine 75 if the deformation of the virtual object causes a change in its current stiffness, and send a drive command to the motor drive module 734 in response to the stiffness adjustment command. In addition, the motor drive module 734 may also be configured to start the motor 721 to transmit the rotation to the axis of the bottom plate of the haptic handheld device through the transmission system 722, thereby adjusting the stiffness to be felt by the user's finger / thumb. In some embodiments, the change in the current stiffness of the virtual object may include being crushed or falling off the virtual object.

[0062] In some other embodiments, the microcontroller 731 can also be configured to: determine the rotation amount of the motor 721 based on the changed stiffness of the virtual object indicated in the stiffness adjustment command; and generate a drive command for the motor drive module 734 to rotate the motor 721 at the determined rotation amount.

[0063] FIG9( b) shows a schematic top view of a transmission system of an actuator mechanism according to an embodiment of the present disclosure. As shown in FIG9( b), the motor 721 may include a drive shaft 721a, and the transmission system 722 may include a worm 722a mounted and fixed to the drive shaft 721a of the motor 721, a bobbin 722b threadedly connected to the worm 722a, at least four rollers 722c, five universal joints 722d, and a cable 722e; wherein each of the at least four rollers 722c has an axis parallel to the axis of the bobbin 722b and perpendicular to the axis of the drive shaft 721a and the worm 722a, and The cable 722e is connected to the bottom plates of the five origami-based contact members 71a-71e via at least four universal joints 722d; the cable 722e is wound around the spool 722b and at least four rollers 722c in sequence, so that the worm 722a can rotate with the rotation of the drive shaft 721a and transmit the rotation to the spool 722b, and the spool 722b rotates the cable 722e to rotate the at least four rollers 722c, thereby synchronously transmitting the rotation to the bottom plates of the five origami-based contact members 71a-71e. The universal joint can be used to transmit the rotation between the top plate and the bottom plate of the curved surface origami-based contact member around the vertical axis.

[0064] In some other embodiments, the transmission system 722 may include four rollers 722c, and in order to save space, the origami-based contact member 71e for the thumb and the origami-based contact member (such as 71b) for the middle finger are connected to the same roller 722c. In this way, the rotation of the base plate of the origami-based contact member forming the five buttons can be synchronously controlled by a motor 721 to perform a cable-based SI-MO (single input multiple output) actuation strategy, thereby achieving a more compact and lightweight structure. In Figure 9 (b), the thick arrow indicates the drive of the spool 722b, and the thin arrow indicates the follow-up rolling of multiple rollers 722c.

[0065] In some other embodiments, the transmission system 722 may further include a tension roller 722f, and the portion of the cable 722e between the spool 722b and the four rollers 722c is tensioned by the tension roller 722f. The tension roller 722f may be used to pre-tension the cable 722e to prevent slippage between the cable 722e and the plurality of rollers 722c.

[0066] In addition, due to the self-locking characteristics of the worm, the structure of the tactile handheld device 700 can withstand the torque of relative rotation between the top plate and the bottom plate of the contact member based on curved origami and maintain a state of specified stiffness, thereby realizing a more energy-efficient system.

[0067] The object-like tactile handheld device 700 can provide artificially triggered active mechanical tactile sensations (with stiffness perception covering a positive and negative range). The microcontroller 731 of the tactile handheld device 700 connects the virtual environment and the actual perception, and achieves the effect of "what the user sees is what the user feels" by synchronously providing various stiffness perceptions based on the virtual objects seen, and guiding these virtual objects to change (not limited to shape) in the virtual environment based on active user input by pressing buttons. For example, for a soft sphere in the virtual environment, the user can feel its softness, and feel its deformation and see its deformed appearance when actively pressed.

[0068] There are various scenarios in which the user grasps various virtual objects (e.g., elastic spheres and crushable spheres, soft spheres and rigid spheres) and senses their corresponding stiffness through the haptic handheld device 700. The bidirectional connection between the user and the virtual objects by the haptic handheld device 700 makes the objects in the virtual environment perceptible to the user and, in turn, deformable in the virtual world. This perception is triggered by the user's active grasping, which is similar to the interaction with real objects in the physical environment, thereby providing a better immersive experience.

[0069] In order to evaluate the tactile perception imparted by the haptic handheld device according to the present disclosure, 12 participants were recruited to identify 4 different spherical objects with different mechanical properties (i.e., "rigid" with high stiffness, "elastic" with relatively low stiffness, "soft" with the lowest stiffness, and "crushed" with negative stiffness) in three different ways: 1) virtual environment through visual information only (i.e., only VR glasses); 2) only active touch (i.e., only the haptic device of the present disclosure); and 3) combined information of vision and touch (VR glasses + haptic device of the present disclosure). Figure 7(c) shows the confusion matrix for these three cases, where the columns and rows correspond to the preset characteristics and the characteristics identified by the participants. As expected, the participants were unable to determine the mechanical properties of the virtual objects based solely on the visual information from the VR glasses. The highest recognition rate was less than 77%, and it is worth noting that the highest recognition rate was less than 22% when identifying two similar objects (i.e., the "elastic" object and the "soft" object). In contrast, when only the disclosed haptic device was used, the recognition rate was almost 100%, indicating that the device can replicate stiffness information. Interestingly, when participants used the haptic handheld device in combination with visual information from the VR glasses, the recognition rate dropped (i.e., for "rigid" and "crushing" objects, the recognition rate was above 91%; and for "elastic" and "soft" objects, the recognition rate was slightly above 80%), which may indicate that touch plays a more important role than visual information in terms of stiffness perception, as the latter is unreliable and sometimes even misleading.

[0070] In order to more objectively evaluate tactile perception, physiological signals (i.e., electromyogram or EMG) from the electrical activity of muscles were recorded when users tried to grasp four objects with different stiffness using four different ways (one way in the physical environment and three ways in the virtual environment). In the physical environment, four spheres (rigid wooden ball, easily deformed (buckled) plastic ball, elastic football #1 with higher pressure, and soft football #1 with lower pressure) were used, which became the benchmark for evaluation. In the virtual environment, when the VR glasses visually presented four spheres (rigid sphere, fragile sphere, elastic sphere, and soft sphere), three grasping methods were presented: 1) using the tactile handheld device of the present disclosure; 2) only using gestures without touching anything in the real physical world; and 3) using a joystick (a common interactive tool currently). Figure 7 (d) shows the RMS (root mean square) value of the EMG signal when grasping various objects (real objects in the physical world or virtual objects in the VR world) under different hand-held conditions. The results clearly show that the haptic handheld device of the present invention exhibits trends very similar to those based on real objects (i.e., higher stiffness stimulates higher EMG voltages), and that crushing motions tend to rapidly reduce this value. In contrast, for the case where only gestures and joysticks are used, the values ​​are indistinguishable, resulting in a lack of realistic tactile perception from a muscle perspective. Statistical analysis further shows that when compared to real objects, the haptic handheld device of the present invention exhibits significant performance in simulating different mechanical stiffnesses (P<0.001 in most cases), providing a distinguishable stiffness perception, while gestures and traditional joysticks produce statistically insignificant perceptions for users (P>0.05).

[0071] According to one embodiment of the present disclosure, another origami-based contact member for active mechanical haptics is also provided. FIG. 10( a) illustrates a schematic diagram of the composition of another origami-based contact member for active mechanical haptics according to an embodiment of the present disclosure. Referring to FIG. 10( a), the origami-based contact member 1000 may include: a top plate 1010, which is exposed to the outside so as to be contacted by a user's body part; a bottom plate 1020; a plurality of pieces of curved origami-based metamaterials 1030, arranged between the top plate and the bottom plate and in a plurality of rows; and cables 1400, which are arranged corresponding to these rows, so that each row has an independent cable 1400. Each piece of curved origami-based metamaterial 1030 has a top end 1030a and a bottom end 1030b, the top end 1030a can be fixed on the top plate 1010, and the bottom end 1030b can be fixed on the bottom plate 1020.

[0072] Fig. 10(b) illustrates a schematic diagram of a curved origami-based metamaterial of an origami-based contact member 1000. As shown in Fig. 10(b), each piece of curved origami-based metamaterial 1030 includes a panel 1031 having a single curved fold 1031a extending along its longitudinal direction, the single curved fold dividing the panel 1031 into two surfaces (surface 1 and surface 2) on opposite sides thereof, and the panel 1031 is configured to be folded along the single curved fold 1031a to form a folding angle between surface 1 and surface 2. In addition, a first hole 1031b is formed on one of the two surfaces (e.g., surface 1), and a second hole 1031c is formed on the other of the two surfaces (e.g., surface 2). In addition, for each row of curved origami-based metamaterial 1030, the corresponding independent cables 1040 pass through two holes cut on the panel in sequence, and are knotted on one side behind each panel 1031, so that when loaded along the vertical axis between the top plate and the bottom plate, the cables are synchronously pulled / released to adjust the folding angle of the panel, thereby achieving variable stiffness ranging from positive stiffness to negative stiffness, which will be sensed by the user's body parts through contact with the top plate 1010.

[0073] Specifically, if Fig.11 As shown, the origami-based contact member 1000 may be formed as a tread member, and the body part is a foot.

[0074] Similar to the origami-based contact member 200 shown in Figure 2(a), the single curved crease 1031a of the origami-based contact member 1000 is composed of the following parts: two end extensions, a middle extension, and two arc-shaped cutting grooves, each cutting groove connecting its adjacent end extensions and middle extensions.

[0075] As shown in FIG. 10( a ), the origami-based contact structure 1000 may further include a plurality of pairs of rings and columns, wherein the columns are fixed at the periphery of a plurality of sheets of curved origami-based metamaterials 1030 and distributed on the base plate 1020 , and the rings are fixed on the bottom side of the top plate 1010 corresponding to the columns, so that each ring can be slidably mounted on the corresponding column.

[0076] Multiple pairs of collars and posts can be used to constrain the tactile platform in the vertical direction only when the user actively steps on it (e.g. Fig.11 In addition, the sliding range between the collar and the column is preset to limit the downward pressing range of the origami-based contact member 1000.

[0077] The origami-based contact member 1000 may further include a distance sensor (not shown) disposed between the top plate 1010 and the bottom plate 1020 to detect vertical displacement of the top plate 1010. For example, the distance sensor may be disposed on the bottom plate 1020.

[0078] Furthermore, as shown in FIG. 10( a ) and FIG. 10 ( b ), each cable 1040 is independent of each other and has a free end 1041 that extends out of the proximal panel to be independently pulled / released.

[0079] According to one embodiment of the present disclosure, a tactile pedaling device for providing active mechanical tactile sensation is provided. Fig.12 As shown, the tactile pedaling device 1200 for providing active mechanical tactile sensation may include FIG. 10(a), FIG. 10(b) or FIG. Fig.11 The origami-based contact member 1210 shown, and specifically, the user's body part is a foot.

[0080] In some other embodiments, the tactile pedaling device 1200 may further include an actuation mechanism 1220 and a control unit 1230, wherein the actuation mechanism includes a cable 1221. The control unit 1230 may be configured to communicate with the VR / AR engine 1240 so as to receive a stiffness adjustment command indicating the current stiffness of the virtual object while tracking the user's active pedaling operation on the virtual object in the VR / AR scene. The control unit 1230 may also be configured to control the actuation mechanism 1220 in response to the stiffness adjustment command so as to synchronously pull / release the cable 1221 to adjust the stiffness to be felt by the user's foot.

[0081] In some other embodiments, the control unit 1230 may further include a microcontroller 1231, a distance sensing module 1232, and a wireless communication interface 1233. The distance sensing module 1232 may be configured to convert the sensed distance change caused by the user's foot actively stepping on the top plate into a voltage change, and the microcontroller 1231 may be connected to the distance sensing module 1232 and forward the voltage change to the VR / AR engine via the wireless communication interface 1233, so that the VR / AR engine can then convert the voltage change into a deformation of the virtual object and change the corresponding VR / AR scene seen by the user through the VR / AR device 1250.

[0082] FIG13(a) illustrates an exploded schematic diagram of the partial components of the actuating mechanism of the tactile pedaling device, and FIG13(b), FIG13(c) and FIG13(d) illustrate schematic diagrams of the transmission system of the actuating mechanism according to an embodiment of the present disclosure. Similar to the tactile handheld device 700, the control unit 1230 may further include a motor drive module (not shown), the actuating mechanism 1220 may further include a motor 1222 and a transmission system 1223 including a cable 1221 (as shown in FIG13(a)), and the microcontroller 1231 may further be configured to: if the deformation of the virtual object causes its current stiffness to change, from the VR / AR engine 1240 (such as Fig.1213(b) receives a stiffness adjustment command indicating a changed stiffness of a virtual object, and sends a drive command to a motor drive module in response to the stiffness adjustment command. In some other embodiments, the motor drive module may also be configured to start the motor 1222 to transmit the pull / release to the cable 1221 through the transmission system 1223, thereby adjusting the stiffness to be felt by the user's foot. In some embodiments, the change in the current stiffness of the virtual object may include being crushed or falling off the virtual object. The motor 1222 may include a drive shaft 1222a (as shown in FIG. 13(b)), and the transmission system 1223 may correspondingly include a worm 1223a mounted and fixed on the drive shaft 1222a of the motor 1222 and rollers 1223b (FIG. 13(b)) arranged corresponding to these rows. In addition, each roller 1223b has an axis perpendicular to the axis of the drive shaft 1222a and the worm 1223a, and is formed with a thread to be threadedly connected to the worm 1223a, and each cable 1221 is wound around the corresponding roller 1223b, wherein the worm 1223a can rotate as the drive shaft 1222a rotates and transmits the rotation to the roller 1223b, and the roller 1223b rotates the cable 1221 to synchronously pull / release the free end of the cable (1 input 5 output as shown in Figures 13(c) and 13(d)).

[0083] Therefore, for the tactile treading device 1200, a two-stage transmission system is designed, which consists of a multi-head worm gear transmission and a multi-knot cable drive transmission, wherein the former transmits the rotation from the motor to four rollers to pull four independent cables simultaneously, while the latter converts the pulling of each cable into simultaneous folding of five pieces of origami-based metamaterials through five knots evenly located behind five moving panels. In this way, simultaneous control of tessellation of origami-based metamaterials with 20 components located in a 4×5 matrix can be achieved by only one motor, thereby forming an easy-to-manipulate and energy-saving actuation system similar to the actuation system of the tactile handheld device 700.

[0084] In some other embodiments, the microcontroller 1231 may be further configured to: determine the rotation amount of the motor 1222 according to the changed stiffness of the virtual object indicated in the stiffness adjustment command; and generate a drive command for the motor drive module to rotate the motor 1222 at the determined rotation amount.

[0085] Benefiting from the scalability of origami structures, metamaterials based on curved origami are constructed in various sizes using different materials (e.g., plastic or steel) and then integrated into two tactile devices (i.e., a tactile handheld device for inducing tactile sensation and a tactile stepping device (e.g., a stepping pad) for generating full-body sensation) for experience (Figure 1(a) and Figure 1(b)). These two experiences produce more realistic sensory perceptions by successfully simulating the physiological and psychological reactions of users, and they are expected to deliver highly immersive virtual experiences with broad application potential in entertainment, remote control, medical treatment, and rehabilitation.

[0086] According to an embodiment of the present disclosure, an immersive VR / AR system for providing active mechanical tactile sensation is also provided. Fig.14 As shown, the immersive VR / AR system 1400 may include a tactile handheld device 700 for providing active mechanical tactile sensation according to any of the embodiments described above, and alternatively or additionally, a tactile treading device 1200 for providing active mechanical tactile sensation according to any of the embodiments described above, as a tactile component.

[0087] The VR / AR engine 1430 may be configured to: communicate with the VR / AR device 1440 and the haptic device 700 and / or the haptic device 1400 at the same time; and send a stiffness adjustment command indicating the current stiffness of the virtual object to the haptic component when tracking the user's active grasping operation and / or active stepping operation on the virtual object in the VR / AR scene. In some other embodiments, the VR / AR engine 1430 may also be configured to send a stream related to the VR / AR scene to the VR / AR device 1440.

[0088] In some embodiments, the VR / AR device 1440 can be configured to: communicate with the VR / AR engine 1430 to receive a stream related to the VR / AR scene and present the VR / AR scene to the user accordingly; and track the user's active grasping and / or active stepping operations on virtual objects in the VR / AR scene.

[0089] For the immersive VR / AR system 1400, the control unit of the tactile handheld device 700 may include a microcontroller, a sampling resistor module, and a wireless communication interface, wherein each panel is made of a substrate deposited with a sensing layer (for sensing the loaded strain), and changes its resistance when the strain is loaded by pressing / releasing the top plate through the user's finger, thumb, or foot; the sampling resistor module is connected to the sensing layer and converts its changed resistance into a voltage change; and the microcontroller is connected to the sampling resistor module and forwards the voltage change to the VR / AR engine via the wireless communication interface. The detailed implementation has been described in conjunction with the drawings related to the tactile handheld device 700, so it will not be repeated here.

[0090] The control unit of the tactile stepping device 1200 may include a microcontroller, a distance sensing module, and a wireless communication interface, wherein the distance sensing module is configured to convert the sensed distance change caused by the user's foot actively stepping on the top plate into a voltage change; and the microcontroller is connected to the distance sensing module and forwards the voltage change to the VR / AR engine via the wireless communication interface. The detailed implementation has been described in conjunction with the drawings related to the tactile stepping device 1200, so it will not be repeated here.

[0091] The VR / AR engine 1430 may also be configured to convert voltage changes into deformations of virtual objects and change corresponding flows associated with the VR / AR scene.

[0092] In the immersive VR / AR system 1400, a highly immersive, touchable closed-loop virtual world can be constructed by combining the tactile perception generated by actively pressing the curved origami with the synchronized visual information from the traditional VR device. At this time, with the curved origami as the key stiffness adjustment component, the user can actively and physically feel what she / he sees in VR through the touch or pressing action initiated by the user through the tactile device. The virtual scene (e.g., urban landscape, ice surface, and grass) serves as the input of the tactile device (e.g., mat and sphere). Based on this input, the folding angle is adjusted in Δβ by the integrated motor to simulate the expected stiffness response of what the user sees in the VR device. Therefore, the user can feel the mechanical stiffness of the object seen in the VR device in real time by actively grasping with the hand or by the foot stepping action centered on the body. On the other hand, the user's active interaction with the curved origami (e.g., by pressing) is recorded as a resistance change, which is achieved by depositing silver nanowires (AgNW) as a sensing layer on the origami panel. Then, an onboard microcontroller is used to convert these changes into voltage changes. The voltage changes on the haptic device are wirelessly communicated with the virtual environment engine (e.g., Unity) in the PC and then wirelessly streamed into the VR device to render the necessary changes in real time (such as breaking the ice surface when the user triggers negative stiffness). Figure 6(b) shows the relative resistance change (ΔR / R0) of the sensing layer when the top of the curved origami is cyclically actively pressed (with a nominal strain of 30% for height changes) at different folding angles (β = 120°, Δβ = 0°, 30°, 60°, and 90°). Two features are observed here: first, the change in resistance is highly repeatable during cyclic pressing and release; second, the folding angle Δβ shows a negligible effect, which is important for changing the virtual environment using a general algorithm (i.e., a Δβ-independent algorithm). Therefore, when a person actively interacts, the virtual environment is changed according to the deformation measured by the resistance change. The experimental results show that the device achieves very stable virtual-real synchronization via its wireless transmission system. It should be noted that the integrated motor drive cable is activated only when the folding angle of the curved origami needs to be changed according to the virtual scene. It then provides various stiffness perceptions to the user without further complex control algorithms or additional actuation. Therefore, only about 150 mW of power dissipation is generated when adjusting the stiffness, thus realizing an energy-saving system for human-triggered active haptics.

[0093] According to an embodiment of the present disclosure, an origami-based contact member for active mechanical haptics is also provided. The origami-based contact member may include: a top plate; a bottom plate; and at least one piece of curved origami-based metamaterial placed between the top plate and the bottom plate, wherein the curved origami-based metamaterial may include a panel, and the variable stiffness of the curved origami-based metamaterial is achieved by twisting the panel (similar to FIG. 2( b)) or by pulling / releasing the panel through a connecting member passing through the panel (similar to FIG. 10( a)), wherein the variable stiffness covers a range from positive stiffness to negative stiffness.

[0094] The origami-based contact members of the torsion panel and the origami-based contact members of the pull / release panel can be made of different materials in different proportions, but can be adjusted to have different stiffness responses using the same working principle.

[0095] The origami-based contact member, tactile handheld device or tactile treading device according to the present disclosure adopts a sophisticated curved origami-based metamaterial, allowing the user to actively generate and perceive mechanical tactile sensations with controllable stiffness ranging from hard to soft and from positive stiffness to negative stiffness. In addition, an immersive VR / AR system in which a tactile handheld device and / or a tactile treading device is integrated can provide accurate and stable virtual-real synchronization with active mechanical tactile sensations, and realize the combination of visual, auditory and active touch sensory perceptions in the AR / VR tactile experience, thereby providing many possibilities for potential applications including daily entertainment, industrial remote operation, psychotherapy and physical rehabilitation.

[0096] The above description is intended to illustrate rather than limit. For example, the above examples (or one or more solutions thereof) can be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features can be combined together to simplify the present disclosure. This should not be interpreted as an intention that the features that do not need to be protected in the present disclosure are necessary for any claim. On the contrary, the subject matter of the present disclosure may be less than the full range of features of the specific disclosed embodiments. Therefore, the following claims are incorporated herein as examples or embodiments in the specific embodiments, and each claim is separately used as a separate embodiment, and it should be considered that these embodiments can be combined with each other in various combinations or arrangements. The scope of the present disclosure should be determined with reference to the full scope of the attached claims and the equivalent forms to which these claims are assigned.

[0097] The above embodiments are only exemplary embodiments of the present disclosure and are not intended to limit the present disclosure. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present disclosure, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. An origami-based contact member for active mechanical haptics, comprising: A top plate, a bottom plate, and at least one piece of curved origami-based metamaterial placed between the top plate and the bottom plate, wherein the top end of the curved origami-based metamaterial is fixed to the top plate and the bottom end thereof is fixed to the bottom plate, and the top plate is exposed to the outside to be contacted by a body part of a user; The curved origami-based metamaterial comprises a panel having a single curved crease extending along a longitudinal direction thereof, wherein the single curved crease divides the panel into two surfaces at two opposite sides thereof, and the panel is configured to be folded along the single curved crease so as to form a folding angle between the two surfaces; The folding angle is configured to be adjusted by rotating the bottom plate so as to achieve a variable stiffness ranging from positive stiffness to negative stiffness when loaded along a vertical axis between the top plate and the bottom plate, which variable stiffness will be sensed by a body part of the user via contact with the top plate.

2. The origami-based contact member according to claim 1, characterized in that The origami-based contact member is formed as a button.

3. The origami-based contact structure of claim 1, wherein: The at least one piece of curved origami-based metamaterial comprises two pieces of curved origami-based metamaterials, wherein one piece of curved origami-based metamaterial is axially symmetric to the other piece of curved origami-based metamaterial.

4. The origami-based contact member according to claim 2, wherein: The base plate is circular and is provided with a shaft which can be rotated by an actuating mechanism.

5. The origami-based contact member according to claim 4, characterized in that The single curved surface fold consists of the following parts: two end extensions, a middle extension and two arc-shaped cutting grooves, and each of the arc-shaped cutting grooves connects its adjacent end extension and the middle extension.

6. The origami-based contact member according to claim 4 or 5, characterized in that The panel is made of a substrate with a sensing layer deposited on it, which is used to sense the applied strain and change its electrical properties.

7. A tactile handheld device for providing active mechanical tactile sensation, comprising:

5. The origami-based contact member according to claim 6, wherein the user's body part is a finger or a thumb; Actuation mechanism and control unit, wherein The control unit is configured to: communicate with the VR / AR engine so as to receive a stiffness adjustment command indicating a current stiffness of the virtual object while tracking an active grasping operation performed by the user on the virtual object in the VR / AR scene; and controlling the actuation mechanism in response to the stiffness adjustment command so as to rotate the axis of the base plate to adjust the stiffness to be felt by the user's finger / thumb; as well as A support case is used to accommodate the five origami-based contact members, the actuation mechanism and the control part, and the support case is provided with five openings for exposing the top plate to the outside.

8. The tactile handheld device according to claim 7, characterized in that: The control unit includes a microcontroller, a sampling resistor module and a wireless communication interface. The sensing layer is configured to change its resistance when strain is applied to the top plate by a pressing / releasing operation performed by the user's finger or thumb; The sampling resistor module is connected to the sensing layer and converts its changed resistance into a voltage change; The microcontroller is connected to the sampling resistor module and forwards the voltage change to the VR / AR engine via the wireless communication interface, so that the VR / AR engine then converts the voltage change into a deformation of the virtual object and changes the corresponding VR / AR scene that the user will see via the VR / AR device.

9. The tactile handheld device according to claim 8, characterized in that: The control unit also includes a motor drive module, and the actuator includes a motor and a transmission system. The microcontroller is further configured to: if the deformation of the virtual object causes a change in its current stiffness, receive a stiffness adjustment command from the VR / AR engine indicating the changed stiffness of the virtual object, and send a drive command to the motor drive module in response to the stiffness adjustment command; The motor drive module is further configured to activate the motor to transmit rotation to the shaft of the base plate via the transmission system, thereby adjusting the stiffness to be felt by the user's finger / thumb.

10. The tactile handheld device according to claim 9, characterized in that: A change in the current stiffness of the virtual object may include being crushed or falling from the virtual object.

11. The tactile handheld device according to claim 9, characterized in that: The motor includes a drive shaft, the transmission system includes a worm mounted and fixed to the drive shaft of the motor, a bobbin threadedly connected to the worm, at least four rollers, five universal joints, and a cable; Wherein, each of the at least four rollers has an axis parallel to the axis of the spool and perpendicular to the axis of the drive shaft and the worm, and is connected to the base plates of the five origami-based contact components via at least four universal joints; the cable is wound around the spool and the at least four rollers in sequence, so that the worm rotates as the drive shaft rotates and transmits the rotation to the spool, and the spool rotates the cable to rotate the at least four rollers, thereby synchronously transmitting the rotation to the base plates of the five origami-based contact components.

12. The tactile handheld device according to claim 9, characterized in that: The microcontroller is further configured to: determine a rotation amount of the motor according to the changed stiffness of the virtual object indicated in the stiffness adjustment command; and generate a drive command for the motor drive module to rotate the motor by the determined rotation amount.

13. The tactile handheld device according to claim 7, characterized in that: The support case is spherical in shape and has five slots for respectively accommodating the five origami-based contact members, each of the slots being provided with a sliding guide for limiting a compression range of a corresponding origami-based contact member.

14. The tactile handheld device according to claim 13, characterized in that: The five origami-based contact members are installed in the support shell according to a common human grasping posture, and the origami-based contact member for the thumb is located on a side of the support shell opposite to a side of the other four fingers.

15. The tactile handheld device according to claim 11, characterized in that: The transmission system includes four rollers, and the origami-based contact members for the thumb and middle finger are connected to the same roller.

16. The tactile handheld device according to claim 11, characterized in that The transmission system further comprises a tensioning roller, and a portion of the cable between the spool and the four rollers is tensioned by the tensioning roller.

17. An origami-based contact member for active mechanical haptics, comprising: a top panel that is exposed to be contacted by a body part of a user; A bottom plate; a plurality of pieces of curved origami-based metamaterials, which are placed between the top plate and the bottom plate and arranged in a plurality of rows; and cables, which are arranged corresponding to the plurality of rows, so that each row has an independent cable; Each piece of the curved origami-based metamaterial has a top end and a bottom end, the top end is fixed on the top plate, and the bottom end is fixed on the bottom plate; Each piece of the curved origami-based metamaterial comprises a panel having a single curved crease extending along a longitudinal direction thereof, wherein the single curved crease divides the panel into two surfaces at two opposite sides thereof, and the panel is configured to be folded along the single curved crease to form a folding angle between the two surfaces; forming a first hole on one of the two surfaces and forming a second hole on the other of the two surfaces; For each row of curved origami-based metamaterials, the corresponding independent cables are sequentially passed through two holes cut on the panel and are knotted on one side behind each panel so as to be synchronously pulled / released to adjust the folding angle of the panel, thereby achieving a variable stiffness ranging from positive stiffness to negative stiffness when loaded along the vertical axis between the top plate and the bottom plate, and the variable stiffness will be sensed by the user's body parts via contact with the top plate.

18. The origami-based contact member of claim 17, wherein: The origami-based contact member is formed as a tread member, and the body part is a foot.

19. The origami-based contact member of claim 17, wherein: The single curved surface fold consists of the following parts: two end extensions, a middle extension, and two arc-shaped cutting grooves, and each of the cutting grooves connects its adjacent end extension and the middle extension.

20. The origami-based contact member according to claim 18 or 19, characterized in that A distance sensor is also included, and the distance sensor is arranged between the top plate and the bottom plate to detect the displacement of the top plate in the vertical direction.

21. The origami-based contact member of claim 17, wherein: It also includes multiple pairs of rings and columns, wherein the columns are fixed on the periphery of the multiple pieces of curved origami-based metamaterials and distributed on the bottom plate, and the rings are fixed on the bottom side of the top plate corresponding to the columns, so that each ring can be slidably mounted on the corresponding column.

22. The origami-based contact member of claim 21, wherein: The sliding range between the collar and the post is preset to limit the depression range of the origami-based contact member.

23. The origami-based contact member according to any one of claims 17 to 19, characterized in that Each cable is independent of the others and has a free end extending out of the proximal panel so as to be pulled / released independently.

24. A tactile pedaling device for providing active mechanical tactile sensation, comprising: The origami-based contact member of claim 23, wherein the user's body part is a foot; as well as an actuating mechanism comprising the cable and a control portion, wherein The control unit is configured to: communicate with the VR / AR engine so as to receive a stiffness adjustment command indicating a current stiffness of the virtual object while tracking an active stepping operation performed by the user on the virtual object in the VR / AR scene; The actuation mechanism is controlled in response to the stiffness adjustment command to synchronously pull / release the cables to adjust the stiffness to be felt by the user's foot.

25. The tactile pedaling device according to claim 24, characterized in that: The control unit includes a microcontroller, a distance sensing module and a wireless communication interface; The distance sensing module is configured to convert the sensed distance change caused by the user's foot actively stepping on the top plate into a voltage change; The microcontroller is connected to the distance sensing module and forwards the voltage change to the VR / AR engine via the wireless communication interface, so that the VR / AR engine then converts the voltage change into a deformation of the virtual object and changes the corresponding VR / AR scene that the user will see via the VR / AR device.

26. The tactile pedaling device according to claim 25, characterized in that: The control unit further includes a motor drive module, the actuating mechanism includes a motor and a transmission system, and the transmission system includes the cable; The microcontroller is further configured to: if the deformation of the virtual object causes a change in its current stiffness, receive a stiffness adjustment command from the VR / AR engine indicating the changed stiffness of the virtual object, and send a drive command to the motor drive module in response to the stiffness adjustment command; The motor drive module is further configured to activate the motor to transmit a pull / release to the cable through the transmission system, thereby adjusting the stiffness to be felt by the user's foot.

27. The tactile pedaling device according to claim 26, characterized in that: A change in the current stiffness of the virtual object may include being crushed or falling from the virtual object.

28. The tactile pedaling device according to claim 26, characterized in that The motor includes a drive shaft, and the transmission system also includes a worm mounted and fixed to the drive shaft of the motor and rollers arranged corresponding to the plurality of rows; The rollers each have an axis perpendicular to the axis of the drive shaft and the worm, and are formed with threads to be threadedly connected with the worm; Each cable is wound around a corresponding roller; The worm rotates as the drive shaft rotates and transmits the rotation to the roller, and the roller rotates the cable to synchronously pull / release the free end of the cable.

29. The tactile pedaling device according to claim 26, characterized in that The microcontroller is further configured to: determine a rotation amount of the motor according to the changed stiffness of the virtual object indicated in the stiffness adjustment command; and generate a drive command for the motor drive module to rotate the motor by the determined rotation amount.

30. An immersive VR / AR system for providing active mechanical tactile sensation, comprising: A tactile handheld device for providing active mechanical tactile sensation according to any one of claims 7 to 16 and / or a tactile treading device for providing active mechanical tactile sensation according to any one of claims 24 to 29, as a tactile component; A VR / AR engine configured to: communicate with both the VR / AR device and the haptic device; send a stiffness adjustment command indicating a current stiffness of the virtual object to the haptic component while tracking the user's active grasping and / or active stepping operation on the virtual object in the VR / AR scene; and send a stream related to the VR / AR scene to the VR / AR device; as well as a VR / AR device configured to: communicate with the VR / AR engine to receive a stream associated with the VR / AR scene and present the VR / AR scene to the user accordingly; And tracking the user's active grasping and / or active stepping operations on the virtual object in the VR / AR scene.

31. The immersive VR / AR system according to claim 30, characterized in that: The control unit of the tactile handheld device includes: a microcontroller, a sampling resistor module and a wireless communication interface, wherein each panel is made of a substrate deposited with a sensing layer for sensing the loaded strain, and changes its resistance when the strain is loaded by pressing / releasing the top panel by the user's finger, thumb or foot; the sampling resistor module is connected to the sensing layer and converts its changed resistance into a voltage change; and the microcontroller is connected to the sampling resistor module and forwards the voltage change to the VR / AR engine via the wireless communication interface; The control unit of the tactile stepping device includes: a microcontroller, a distance sensing module and a wireless communication interface, wherein the distance sensing module is configured to convert the sensed distance change caused by the user's foot actively stepping on the top plate into a voltage change; the microcontroller is connected to the distance sensing module, and forwards the voltage change to the VR / AR engine via the wireless communication interface; and The VR / AR engine is also configured to convert the voltage change into a deformation of the virtual object and modify a corresponding stream associated with the VR / AR scene.

32. An origami-based contact member for active mechanical haptics, comprising: roof; Base plate; and at least one piece of metamaterial based on curved origami placed between the top plate and the bottom plate, Wherein, the metamaterial based on curved origami comprises a panel, and variable stiffness of the metamaterial based on curved origami is achieved by twisting the panel or pulling / releasing the panel through a connecting member passing through the panel; The variable stiffness ranges from positive stiffness to negative stiffness.

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