Kirigami-based microscale 3D multi-functional structures

Abstract

A kirigami device (1) comprising a foldable substrate (9), the substrate comprising: one or more discontinuous cuts (6) arranged such that the substrate may be moved from a planar configuration wherein the substrate extends substantially in a first plane, to an interlocking configuration wherein the substrate forms an expanded structure extending in three dimensions; and an interlocking mechanism comprising a first component and a second component, wherein the first component is disengaged from the second component in the planar configuration, and wherein the first component is engaged with the second component in the interlocking configuration, wherein the interlocking mechanism is arranged to retain the substrate in the interlocking configuration

Description

[0001] Kirigami-based microscale 3D multi-functional structures

[0002] The present disclosure relates to a kirigami device and methods of use thereof.

[0003] Background

[0004] Kirigami, a Japanese paper art form similar to origami but involving cutting in addition to folding, has recently enabled the creation of novel functional tools and programmable systems. Modern kirigami, like origami, has evolved beyond traditional paper folding, incorporating techniques such as marking, cutting, gluing, and taping to create intricate structures. The complexity inherent in the interactions between different parts of a kirigami structure enhances its versatility. This adaptability makes kirigami methodologies applicable in contexts where minimally invasive approaches are essential, as evidenced by its use in scientific applications.

[0005] Advantages of kirigami-inspired approaches extend to the fabrication of compact yet highly functional structures that can conform to biosystems, allow for compact deployment, and provide shape-shifting capabilities from two-dimensional (2D) to three-dimensional (3D) structures. These methods also offer cost efficiency, reduced complexity and fabrication time, enabling rapid prototyping.

[0006] While challenges of kirigami-inspired approaches persist, recent advancements have shown potential to revolutionize diagnostics, drug delivery, and therapies in the biomedical research field and applications. Continued efforts to advance the practical applications and effective implementation of kirigami, particularly in the integration of kirigami structures into functional devices and systems, remains an important focus for further development.

[0007] One significant hurdle is that kirigami devices often require the application of a constant force to remain in a particular configuration. This complicates the fabrication of kirigami devices, making it difficult to automate their use in various applications. For example, Babaee, S. et al., Nat. Mater. 20, 1085-1092 (2021) discloses a kirigami-inspired stent for sustained local delivery of therapeutics that comprises a pressure valve in order to maintain an overpressure that holds the device in a folded state.

[0008] Thus, there exists a need for kirigami devices that can, in a simple way, maintain a specific device configuration. Summary

[0009] Advantageously, the present disclosure addresses the above mentioned challenges by having an interlocking mechanism that retains the structure in a certain configuration, such as an interlocking configuration, without the requirement of a constant application of an overpressure.

[0010] Therefore, in a first aspect, the present disclosure relates to a kirigami device comprising a foldable substrate, the substrate comprising:

[0011] • one or more discontinuous cuts arranged such that the substrate may be moved from a planar configuration wherein the substrate extends substantially in a first plane, to an interlocking configuration wherein the substrate forms an expanded structure extending in three dimensions; and

[0012] • one or more interlocking mechanism comprising a first component and a second component, wherein the first component is disengaged from the second component in the planar configuration, and wherein the first component is engaged with the second component in the interlocking configuration, wherein the interlocking mechanism is arranged to retain the substrate in the interlocking configuration.

[0013] The interlocking mechanism may be arranged in many different ways as disclosed elsewhere herein. Typically it comprises a first component and a second component that are arranged to engage such that the kirigami device is retained in the expanded structure. Thus, the first component and the second component may be arranged on different parts of the foldable substrate, and arranged such that when the foldable substrate is moved into the interlocking configuration, said two components engage, whereby the foldable substrate is retained as an expanded structure.

[0014] In some examples, the kirigami device may be resilient, such that it would spring back to, or towards, the planar configuration, unless prevented by the interlocking mechanism. The interlocking mechanism may be arranged such that disengaging of the interlocking mechanism may be carried out by applying a force in a different direction than a tension force acting to spring back the kirigami device to or towards its planar configuration, such as towards a relaxed, non-stressed configuration. In specific examples, the foldable substrate may be symmetric, for example in its planar configuration, with an axis of symmetry parallel to a folding / bending axis, wherein the kirigami device is moved from the planar configuration to the interlocking configuration by folding and / or bending of the kirigami device along said folding / bending axis. In some examples, said axis of symmetry overlaps with the folding / bending axis. Many different configurations by which the kirigami device is folded and / or bent from a planar configuration to an interlocking configuration whereby the device forms an expanded structure. Thus, it would be impossible to explicitly state all different arrangements of discontinuous cuts, bends and / or folds that would result in a kirigami device that can be moved from being in a planar state into an expanded state wherein the device extends in three dimensions.

[0015] However, the presently disclosed kirigami device is arranged such that it is retained in an interlocking configuration, such as in its expanded state, without the requirement of a continuous supply of a force, such as an elevated pressure. The presently disclosed kirigami device may therefore be simpler to manufacture and also simpler to operate, without for example a requirement of bulky and complicated pressure devices.

[0016] Further, when the interlocking mechanism is engaged, it acts to increase the stability and rigidity of the kirigami device by facilitating a connection between different parts of the foldable substrate. Thus allowing the foldable substrate to withstand higher forces while maintaining the overall shape and / or configuration, which may be important for examples in instances when the kirigami device is used as a microneedle (e.g. for drug injection) and as an atomic force microscope (AFM) tip.

[0017] In specific examples, the first component and the second component of the interlocking mechanism are integral with the rest of the foldable substrate. Thus, the foldable substrate may be manufactured through one or more cuts in a planar substrate, including the first and the second component. This simplifies manufacturing of complex structures significantly, as such structures can be manufactured in parallel by making one or more cuts in a planar substrate without time consuming 3D printing techniques or expensive cleanroom facilities, thereby significantly decreasing the associated manufacturing costs, and increasing manufacturing speed. The kirigami device of the present disclosure can be used in many different applications. In one example, the presently disclosed kirigami device is arranged for drug delivery and / or for electrical stimulation of a part of the body, for example the brain, such as by comprising one or more microneedles.

[0018] A tip structure as used herein refers to a narrowing of the foldable substrate. The tip structure may be for example a distal end of the foldable substrate or a part thereof, such as a tip, edge, narrow section, or a pointed section. The trip structure may for example be a triangular section of the foldable substrate, or a vertex of a triangular section of the foldable substrate. The tip structure may thus be an integral part of the foldable substrate and / or provided in the same material.

[0019] A pin as used herein refers to one or more elongated and / or sharp objects, such as a microneedle array. The pin may be a structure that is not integral with the rest of the foldable substrate. Thus, the pin may for example be a structure that has been attached to the foldable substrate, for example a carbon nanotube, a nanowire or another structure, such as a structure having at least one dimension in the micronrange. The foldable substrate may thus comprise a pin. In some examples the tip structure comprises a pin. For example, a pointed end of the foldable substrate, such as an integral part of the foldable substrate may comprise a pin, such as a carbon nanotube or a microneedle array.

[0020] Further, the presently disclosed kirigami device may be arranged as a cantilever and / or a tip structure for atomic force microscopy (AFM). The device may also be arranged as an atomic force microscopy (AFM) probe, with the foldable substrate comprising one or more pins made of materials such as silicon, silicon nitride, metal, mineral, or carbonaceous materials like carbon nanotubes. These pins may have diameters in the range of 10 nm to 40 nm, or more preferably from 5 nm to 20 nm, and even more preferably from 1 nm to 5 nm, allowing for precise measurements at the nanoscale. Even further, the presently disclosed kirigami device may be arranged for photonic stimulation of a part of the body, e.g. the brain, such as by comprising one or more optical waveguides. The kirigami device may for example be arranged such that it can combine photonic stimulation with electrical stimulation of said body part. Further, the kirigami device may be arranged as a micro antenna array, for example wherein the tip structures are provided as micro antennas, another example of applications include integrated circuit (IC) signal pins.

[0021] Although, the above-mentioned examples show a few application areas of the kirigami device, the use of the presently disclosed kirigami device is not limited to the above mentioned examples, instead the presently disclosed kirigami device can beneficially be used in a wide variety of applications and technical fields.

[0022] In an example, the kirigami device comprises at least one tip structure, which may be arranged such that, in the interlocking configuration, the tip structure is arranged at an angle with respect to the first plane. Thus, typically, the foldable substrate may be moved from an initial planar configuration wherein it is substantially planar, to an interlocking configuration wherein it substantially expands in three dimensions.

[0023] In the interlocking configuration of the presently disclosed example, the foldable substrate comprises cuts that are arranged such that, when the foldable substrate is moved into its expanded state (i.e. into the interlocking configuration), at least one tip structure is arranged at an angle with respect to the first plane. The tip structure may thus be arranged at an angle with respect to the general plane of the rest of the foldable substrate.

[0024] Thus, the kirigami device may be arranged such that, in the interlocking configuration, the tip structure is arranged at an angle with respect to the rest of the foldable substrate. Moreover, the foldable substrate may be arranged such that, when moving said structure from the planar configuration to the interlocking configuration, at least a part of the tip structure is moved out of the first plane of the foldable substrate.

[0025] In this way, bending or folding the foldable substrate, from the planar configuration to the interlocking configuration, such as by stretching of the foldable substrate, can result in one or more tip structures, and / or one or more pins of each of said tip structures, being oriented at an angle with respect to at least a part of the rest of the foldable substrate.

[0026] In an embodiment of the present disclosure, the foldable substrate comprises one or more discontinuous cuts that may be arranged such that the foldable structure is divided into a plurality of substrate areas. These substrate areas may have different shapes, such as polygonal shapes including triangles, squares, and / or trapezoids. The substrate areas can be arranged in adjacent configurations, allowing for complex three- dimensional structures when in the interlocking configuration.

[0027] The kirigami device can be arranged such that, when in the interlocking configuration, at least one tip structure is arranged at an angle with respect to the first plane. The tip structure may include jagged shapes or may be adapted to include one or more electrodes or waveguides. Such configurations allow the kirigami device to perform functions such as electrical, optical (e.g., photonic), and / or mechanical stimulation, as well as drug delivery.

[0028] In one embodiment of the present disclosure, the foldable substrate is arranged such that it can be moved from the planar configuration to the interlocking configuration upon stretching of the foldable substrate, such as in stretching of the foldable substrate in the first plane, for example by stretching the foldable substrate along an axis parallel to the first plane. Alternatively, or additionally, the foldable substrate is arranged such that it can be moved from the planar configuration to the interlocking configuration by folding, such as upon folding of the foldable substrate.

[0029] The interlocking mechanism is typically arranged to facilitate, and maintain, connection between different parts of the foldable substrate, such that it retains the substrate in the interlocking configuration. In the preferred embodiment of the present disclosure, the interlocking mechanism comprises at least two components, the first and the second component, wherein the first component is distant from the second component in the planar configuration. For example, the first component and the second component of the interlocking mechanism are located at opposite parts / edges of the foldable structure, when the foldable structure is in the planar configuration.

[0030] The foldable substrate may comprise a single interlocking mechanism or a plurality of interlocking mechanisms. For example, the foldable substrate may comprise a pair of interlocking mechanisms, or even more interlocking mechanisms. Each interlocking mechanism may comprise a first component and a second component which may be configured as described elsewhere herein. For example, each first component may be configured to interlock with the corresponding second component, such that the foldable substrate is retained in the interlocking configuration. Preferably, the first component comprises an engaging element and the second component comprises a retaining element. In the preferred embodiment of the present disclosure, the engaging element is arranged to engage with the retaining element when the foldable substrate is in the interlocking configuration.

[0031] The engaging element may for example be a widening, a protrusion or a hook element, that is arranged to engage with a corresponding element of the second component. The retaining element may for example be an aperture, a hole, a recess, or a hook element that is arranged to engage with a corresponding element of the first component. Thus, in one example, the engaging element may be a hook element while the corresponding element is a hook element. Alternatively, the engaging element may be a protrusion while the corresponding element is a recess. Many different alternatives of combinations of engaging elements and corresponding elements are possible, and it would be obvious for a skilled person to select an engaging element that is suitable for a particular corresponding element.

[0032] The engaging element and the corresponding element may for example be arranged to form a snap-fit connection, or alternatively the engaging element and the corresponding element may be provided as hook elements. The hook elements may for example, each, have a curved shape, such as a J-shape or a U-shape, and be arranged such that they can engage, and thereby retain the foldable substrate in the interlocking configuration.

[0033] When the interlocking mechanism is engaged, it is typically arranged to increase the stability of the kirigami device by facilitating a connection between different parts of the foldable substrate. It is also designed to provide stability and unwanted unfolding or prevent the folded substrate from returning to its original 2D initial shape.

[0034] In a further aspect, the present disclosure relates to a method of manufacturing a kirigami device. The method comprising:

[0035] • providing a foldable substrate; and

[0036] • forming, in the foldable substrate, one or more discontinuous cuts and an interlocking mechanism. The method may for example be arranged for manufacturing the kirigami device as disclosed elsewhere herein.

[0037] Description of drawings

[0038] Fig. 1 is a schematic illustration of one embodiment of the presently disclosed kirigami device showing the kirigami device in its planar configuration.

[0039] Fig. 2 is a schematic illustration of one embodiment of the presently disclosed kirigami device that has been folded from its planar configuration.

[0040] Fig. 3 is a schematic illustration of one embodiment of the presently disclosed kirigami device, wherein the tip structure comprises a pin, such as for use as an AFM probe.

[0041] Fig. 4 is a schematic illustration showing an interlocking mechanism according to one embodiment of the presently disclosed kirigami device.

[0042] Fig. 5 is a schematic illustration of one embodiment of the presently disclosed kirigami device, in the interlocking configuration, wherein the tip structure comprises a pin.

[0043] Fig. 6 is a schematic illustration of one embodiment of the presently disclosed kirigami device in its planar configuration.

[0044] Fig. 7 is a schematic illustration of one embodiment of the presently disclosed kirigami device in its planar configuration, having a variable interlocking mechanism for adjusting the angle of the one or more tip structures.

[0045] Fig. 8 is a schematic illustration of one embodiment of the presently disclosed kirigami device.

[0046] Fig. 9 is a schematic illustration of one embodiment of the presently disclosed kirigami device, having multiple tip structures.

[0047] Fig. 10 is a schematic illustration of one embodiment of the presently disclosed kirigami device comprising electrodes. Fig. 11 is a schematic illustration of one embodiment of the presently disclosed kirigami device that is arranged to move to the interlocking configuration upon stretching of the foldable substrate.

[0048] Fig. 12 is a schematic illustration of one embodiment of the presently disclosed kirigami device comprising multiple tip structures.

[0049] Detailed description

[0050] The term "interlocking mechanism," as used herein, refers to a structural feature of the kirigami device designed to engage and secure different parts of the foldable substrate in a stable three-dimensional configuration. This mechanism typically involves a first component (which can include an engaging element) and a second component (which can include a retaining element) that interact to maintain the substrate in its interlocking configuration, preventing it from easily returning to its planar configuration. The interlocking mechanism may include various designs, such as widening elements, tabs, protrusions, apertures, holes, notches, recesses, or combinations thereof, and is generally integral to the foldable substrate itself.

[0051] The term "foldable substrate," as used herein, refers to the base material of the kirigami device that is capable of being folded, bent, or otherwise deformed from a two- dimensional planar configuration into a three-dimensional structure. The substrate is typically flexible and can be made from various materials such as polymers, metals, or composites. The foldable substrate may incorporate one or more cuts, which may be continuous or discontinuous, to facilitate the transition from the planar configuration to the interlocking configuration , allowing the substrate to be dynamically shaped.

[0052] The term “folding,” as used herein, encompasses a range of deformations including bending, twisting, warping, and other forms of altering the shape of the foldable substrate. In general, folding refers to any process by which the foldable substrate, or a portion thereof, is transformed from a substantially two-dimensional state into a three- dimensional configuration. This transformation may include various mechanical actions that change the spatial orientation of the substrate, resulting in folds, angles, curves, or other structures that extend out of the original plane of the substrate, creating a stable three-dimensional form. The term "planar configuration," as used herein, refers to a state of the kirigami device in which the foldable substrate extends substantially within a single plane. In this configuration, the various components of the interlocking mechanism are disengaged, and the device can remain in a substantially two-dimensional form. This configuration is typically the starting point before the substrate is manipulated into the interlocking configuration.

[0053] The term "interlocking configuration," as used herein, refers to the three-dimensional state of the kirigami device achieved after the foldable substrate has been folded, bent, or otherwise deformed from its planar configuration. In this configuration, the components of the interlocking mechanism are engaged, holding the substrate in its expanded structure and preventing it from returning to the planar configuration without the application of force.

[0054] The term "tip structure," as used herein, refers to a specific part of the foldable substrate that is designed to have a pointed, narrow, or otherwise specialized end. This structure may be used for various applications, including as a needle for drug delivery, a pin for AFM measurements, or an electrode for electrical stimulation. The tip structure may be located at one or more vertices of geometrical shapes formed within the substrate, and it may include additional features such as pins, electrodes, or waveguides.

[0055] The term "discontinuous cut," as used herein, refers to a break or separation in the foldable substrate that does not extend continuously through the entire substrate. Discontinuous cuts are used to define distinct substrate areas and facilitate the folding and deformation of the substrate into a three-dimensional structure. These cuts may create geometric shapes such as triangles, squares, or trapezoids within the substrate, and they play a crucial role in enabling the transition from the planar to the interlocking configuration.

[0056] The term "engaging element," as used herein, refers to a component of the interlocking mechanism. This element is designed to interact with the retaining element to secure the foldable substrate in the interlocking configuration. The engaging element may take various forms, including but not limited to hooks, protrusions, widened sections, or other features that are capable of fitting into or locking with corresponding features of the retaining element. The term "retaining element," as used herein, refers to a component of the interlocking mechanism. This element is designed to receive or lock with the engaging element to hold the kirigami device in the interlocking configuration. The retaining element may include features such as apertures, holes, recesses, notches, or other complementary features that are specifically shaped to engage with the engaging element.

[0057] The term "optical waveguide," as used herein, refers to a physical structure within the kirigami device that is capable of guiding light from one point to another with minimal loss. Optical waveguides are typically used in applications where light needs to be directed with precision, such as in photonic stimulation of biological tissues. The waveguide may be integrated into the tip structure or other parts of the foldable substrate.

[0058] The term "electrode," as used herein, refers to a conductive component of the kirigami device that is used to measure, deliver, or stimulate electrical signals. Electrodes may be integrated into the tip structure or other areas of the foldable substrate and can be used for various biomedical applications, including sensing and stimulation of body tissues. Electrodes may be coated with biocompatible materials to enhance their functionality and durability.

[0059] The present disclosure relates to a kirigami device comprising a foldable substrate, which may be flexible and / or bendable, allowing for folding. The substrate can include one or more cuts (continuous and / or discontinuous) arranged so that the substrate may be moved from a planar configuration, where the substrate extends substantially in a first plane, to an interlocking configuration, where the substrate forms an expanded structure extending in three dimensions. Consequently, different parts of the foldable substrate may be deformed and / or displaced differently when moving the foldable substrate from the planar configuration to the interlocking configuration.

[0060] In some embodiments, the kirigami device may comprise one or more interlocking mechanisms. Each interlocking mechanism may comprise or consist of a first component and a second component. The planar substrate can be arranged such that the first component is disengaged from the second component in the planar configuration, while the first component is engaged with the second component once the planar substrate is in the interlocking configuration. Upon engaging the first component with the second component, the interlocking mechanism can help retain the substrate in the interlocking configuration. The one or more interlocking mechanisms can, each, feature two components that latch onto each other directly. One component may comprise an engaging element, while the other may comprise a corresponding retaining element. The latching mechanism can be adapted to prevent the components from losing their engagement, ensuring that they do not move back towards the planar configuration without deliberate action. The components are designed to create an independent and secure lock by engaging with one another.

[0061] The interlocking mechanism may thus provide stability through the direct interaction of the engaging and retaining elements, forming a secure, self-contained connection. This design can help ensure that the structure remains stable in the three-dimensional configuration.

[0062] Upon disengagement of the engaging and retaining elements, the components may return to their original planar configuration. This transition can be facilitated by further moving the components in the direction that leads towards the three-dimensional configuration, allowing any latching elements to disengage in a controlled manner. Such a design may ensure that the kirigami device can be easily manipulated between planar and three-dimensional states as required. Thus, the components may be arranged so that, once in the interlocking configuration, further movement towards the interlocking configuration is required to disengage the components. These components actively engage with each other to form a secure connection. Such active engagement helps ensure that the components remain securely latched, providing a robust and reliable interlocking system that can be disengaged only through controlled movement along the intended direction.

[0063] The use of engaging and retaining elements in the interlocking mechanism can enhance the stability and structural integrity of the kirigami device. These elements may be designed to engage in a complementary fashion, where their specific shapes — whether they are widenings, tabs, protrusions, apertures, or recesses — help prevent unintentional separation. This design may help the device remain locked in its three- dimensional form under various conditions and stresses.

[0064] In some examples, a greater force may be required to move the foldable substrate from the interlocking configuration to the planar configuration than to move the foldable substrate from the planar configuration to the interlocking configuration. This difference in force is typically a result of the engagement between the first and second component, which, once engaged (or interlocked), may require a significant force to disengage. Alternatively, or additionally, the interlocking mechanism can be arranged such that moving the kirigami device to the interlocking configuration automatically initiates engagement between the first component and the second component. Disengaging these components may require additional steps or movements.

[0065] In some embodiments, the foldable substrate can include at least one tip structure or a plurality of tip structures. In the interlocking configuration, the kirigami device may be arranged such that the one or more tip structures are positioned at an angle with respect to the first plane. The kirigami device may be arranged such that, in the interlocking configuration, the tip structure is oriented at an angle with respect to the rest of the foldable substrate. Furthermore, the foldable substrate may be arranged such that, when moving the structure from the planar configuration to the interlocking configuration, at least a part of the tip structure is moved out of the first plane of the foldable substrate.

[0066] For example, the one or more discontinuous cuts can be cuts through the foldable structure. Additionally, the plurality of cuts may be arranged such that the foldable structure is divided into a plurality of substrate areas with shapes such as triangles, squares , and / or trapezoids. There may be at least two substrate areas. The substrate areas can consist of the same or different shapes. Furthermore, the cuts may also define additional substrate areas within existing substrate areas.

[0067] In another embodiment, the one or more cuts can divide the foldable substrate into at least two main shapes. The two shapes may consist of two rectangular / square areas, two triangular areas, and two trapezoidal shapes, or any combination thereof. The two shapes may be partially joined from at least one side.

[0068] In some configurations, the foldable structure may have a rectangular shape, such as a square. Additionally, the foldable structure may comprise one or more cuts. In a preferred embodiment, the kirigami device may include a discontinuous cut that runs parallel to the shortest length of a rectangular substrate area. The cut can divide the rectangular shape into at least two sections, a first section and a second section. The first section may comprise a cut that follows the shape of an arrowhead or a triangle without a cut at the base of the triangle. Additionally, the first section may be connected to one of the components of the interlocking mechanism, such as the engaging element. The engaging element may be connected to the shortest side of the rectangular shape. The second section of the rectangular shape may comprise a retaining element such as an aperture or a hole. The aperture or hole can have a corresponding shape that matches the engaging element.

[0069] Similarly, the foldable structure may have a rectangular shape, such as a square. Additionally, the foldable structure may comprise one or more cuts. These cuts may pass through the foldable substrate. In one embodiment of the present disclosure, the foldable substrate may feature a cut parallel to the shortest length of the rectangle. The cut can separate the rectangular shape into at least two sections, one section comprising a triangular shape wherein the vertex of the triangular shape faces away from the cut that separates the rectangle into two sections.

[0070] Additionally, the first section may comprise one or more components of the interlocking mechanism, for example, the engaging element. The engaging element may be connected to the shortest side of the rectangular shape.

[0071] In some configurations, the engaging element may comprise two hook elements. These hook elements may be positioned at the corners of one of the sections, such as the first section, along the shorter length of the rectangle. The hook elements may be located at the opposite side of the cut that divides the rectangle into two sections. Moreover, the second section of the rectangular shape may comprise a retaining element, which may be adjustable so that the corresponding hook element interlocks with it. The adjustable retaining elements may be located alongside the long side of the rectangle, particularly along the longest side of the rectangular structure. The adjustable retaining element may be used for adjusting the angle of the one or more tip structures when in the interlocking position.

[0072] In certain embodiments, the foldable substrate may be designed to transition from the planar configuration to the interlocking configuration upon the application of a stretching force. This stretching force can be applied within the first plane, such as by exerting force on the ends of the device while it is in the planar configuration. As the substrate is stretched, various parts of the foldable substrate can be displaced or deformed in a controlled manner, causing the substrate to move towards the interlocking configuration.

[0073] During this process, the movement of the substrate may cause the components of the interlocking mechanism to gradually approach each other. As the stretching continues, the engaging element and the corresponding retaining element may automatically align and engage with one another, securing the substrate in its three-dimensional interlocking configuration. This automatic engagement can occur without the need for additional manual manipulation, making the transition efficient and reliable.

[0074] Moreover, this method of transitioning from a planar to an interlocking configuration may be particularly advantageous in applications where rapid or automated deployment of the kirigami device is beneficial. For example, by applying a uniform stretching force, the device can be moved into its operational three-dimensional structure in a single step, with the interlocking mechanism securing the configuration **immediately upon engagement. This characteristic can be especially useful when multiple kirigami devices are fabricated and operated in parallel, allowing for the simultaneous deployment of many devices. With this approach, large arrays of kirigami devices can be stretched in unison, leading to the coordinated transition of each device to its interlocking configuration, such as pointing upwards or forming a desired three- dimensional structure.

[0075] In some instances, a single kirigami device may comprise multiple pins or needle structures, making this method an efficient way to fabricate and deploy numerous functional elements, such as transdermal needles or AFM needles. This parallel fabrication technique can streamline production processes, allowing for the simultaneous creation and deployment of multiple functional tips across many devices with minimal effort.

[0076] The stretching force applied in a specific direction or manner can also be used to control the final orientation and stability of the interlocking configuration. The design of the discontinuous cuts and the geometry of the substrate can be optimized to ensure that the transition to the interlocking configuration occurs smoothly and that the components of the interlocking mechanism engage correctly.

[0077] Furthermore, once the interlocking mechanism is engaged, the device can remain in the interlocking configuration until an appropriate force is applied to disengage the mechanism, allowing the substrate to return to its planar configuration if needed. This feature may be particularly advantageous in applications requiring reliable and repeatable transitions between configurations, enhancing the functionality and versatility of the kirigami device. In another embodiment, the foldable substrate may transition from the planar configuration to the interlocking configuration upon the application of a folding force, such as folding along a folding axis. This folding axis can be positioned between a first section and a second section of the kirigami device, with the first section comprising the first component and the second section comprising the second component.

[0078] The kirigami device may comprise a plurality of interlocking mechanisms. When in the interlocking position, the interlocking mechanisms may facilitate the connection between the different parts of the foldable substrate, helping to retain the substrate in the interlocking configuration while enhancing the structural integrity of the kirigami device.

[0079] In this context, the interlocking mechanism may include at least two components, one component being the first and the other being the second. Typically, the first component and the second component of the interlocking mechanism may be located at opposite ends of the foldable structure when the foldable structure is in the planar configuration.

[0080] The engaging element can be designed to engage with the retaining element when the foldable substrate transitions to the interlocking configuration, thereby retaining the kirigami device in the interlocking configuration and helping to prevent unwanted unfolding. The kirigami device may be arranged such that the engaging element engages with the retaining element automatically when moving the kirigami device from the planar configuration to the interlocking configuration. Generally, a higher force may be required to disengage the engaging element from the retaining element compared to the force needed to engage them.

[0081] The interlocking mechanism can be arranged such that disengaging this mechanism can be done by applying a force in a different direction than the force acting to move the kirigami device to or towards its planar configuration. Thus, the kirigami device may be resilient, such that it tends to spring back to or towards the planar configuration. However, the interlocking mechanism may prevent the kirigami device from springing back to or towards the planar configuration, and / or a relaxed non-stressed configuration, by counteracting a tension force.

[0082] In one embodiment, the engaging element may comprise a widening, potentially a protrusion or a hook element, arranged to engage with a corresponding part of the retaining element. Additionally, the retaining element may comprise an aperture or a hole, potentially a recess or a hook element, arranged to engage with a corresponding part of the engaging element.

[0083] The first and second components of the one or more interlocking mechanisms may comprise a hook element. Preferably, the hook elements of the interlocking mechanism can have a bent, curved, or angled shape, such as a J-shape, U-shape, or V-shape. When the interlocking mechanism is engaged, it may facilitate a connection of the foldable substrate to enhance the mechanical properties of the kirigami device. It is also configured to provide stability and reduce the likelihood of unwanted unfolding and / or to prevent the folded substrate from returning to its original 2D initial shape.

[0084] In some configurations, the interlocking mechanism can be arranged to increase the stability of the kirigami device by joining parts of the foldable substrate that are separated in the planar configuration. For example, the interlocking mechanism may be arranged directly between two parts of the kirigami device that are not directly connected in the planar configuration. Thus, the interlocking mechanism may be designed so that, in the interlocking configuration, a first part of the kirigami device contacts the interlocking mechanism, such as the engaging element. The engaging element may then directly contact a corresponding part of the interlocking mechanism, such as a retaining element, and this retaining element may directly contact a second part of the foldable substrate. In the planar configuration, the first part may contact the retaining element, and the second part may contact the engaging element, however, the first part and the second part are not directly linked by the interlocking mechanism, such as the retaining element and the engaging element.

[0085] In some embodiments, the kirigami device can include one or more substrate areas, which may have the same or different geometrical shapes, along which edges are folded in such a way that the kirigami device can transition to the interlocking configuration.

[0086] The one or more geometrical shapes may include a triangle and a square shape. In one example, the geometrical shapes are joined by connecting a triangle’s base side to a side of the rectangular / square-shaped side. The triangular shape may be an isosceles or an equilateral triangle. These geometrical shapes may be at least partially separated by a straight cut and / or a fold when in the interlocking configuration. In some embodiments, the one or more tip structures may be located at one of the vertices of a geometrical shape or another structure having at least one pointed end, such as a triangle-shaped structure. For example, the tip structure may be located at a vertex opposite a base of a triangle. In one example, the tip structure can comprise a pin, such as a pin for AFM measurements. Alternatively, the one or more tip structures may comprise one or more electrodes and / or one or more optical waveguides.

[0087] The pin can have a diameter in the size range from 10 nm to 40 nm, such as 5 to 20 nm, or even 1 to 5 nm. The pin may have a tubular shape. In some embodiments, the pin can have a carbonaceous material deposition, such as carbon nanotubes. This pin can be arranged for AFM measurements. The tip structure may comprise said pin and / or the tip structure can comprise an AFM cantilever with said pin.

[0088] Additionally, in some of the embodiments of the present disclosure, the foldable structure may comprise an aperture. The aperture may be located in the rectangular / square section of the foldable structure.

[0089] AFM

[0090] AFM microscopes have become a widely used technique in many scientific fields due to their unique ability to image and characterize structures in liquid, ambient, and vacuum environments. The level of detail obtained from AFM images, however, can depend significantly on the size, shape, and terminal functionality of the probe tips used for imaging. Various methodologies have been explored to create ‘ideal’ tips. The presently disclosed kirigami device offers a method for AFM probe production that does not rely on cleanroom facilities, potentially enhancing cost efficiency, reducing complexity and manufacturing time, and improving reconfigurability and biocompatibility.

[0091] Commonly, commercially available AFM probes consist of microfabricated silicon or silicon nitride cantilevers with integrated pyramidal tips. These tips can have a radius of curvature less than 10 nm but are often larger, and have pyramid half-cone angles of about 35 degrees. The large cone angle can limit the effectiveness of these tips in imaging deep and narrow features. Super sharp silicon tips with a radius of curvature as small as 10 nm and half-cone angles of about 10 degrees have also been reported. However, these tips may involve high costs in special cleanroom processes, exhibit limited stability due to the brittleness of the fine silicon tip, and show considerable tip- to-tip variations. AFM probes have evolved significantly since the early use of a diamond shard glued onto a hand-cut gold foil cantilever. The breakthrough in tip technology came with the application of cleanroom microfabrication techniques to mass-produce AFM tips. However, these cleanroom microfabrication techniques are still excessively expensive, creating a need for new AFM probe fabrication methods.

[0092] In one embodiment, the kirigami device is used as an AFM probe. For example, a triangle and a square shape can be joined by connecting the triangle’s base side to any side of the rectangular / square-shaped side. The triangular shape can be an isosceles or an equilateral triangle. The two shapes may be partially separated by a straight cut.

[0093] The foldable structure can comprise a tip structure. The tip structure can be located at one of the vertices of the triangle-shaped structure, for example, at the vertex opposite the base of the triangle. The tip structure may comprise a pin for AFM measurements, such as a needle. In some examples, the pin structure can have a carbonaceous material deposition such as carbon nanotubes. The material deposition forms a pin structure at or near the tip of the foldable substrate. The pin structure can have a diameter size between 10 to 40 nm, more preferably 5 to 20 nm, and even more preferably 1 to 5 nm. The pin structure can comprise one or more needles, such as one or more microneedles.

[0094] An Atomic Force Microscope (AFM) needle, also referred to herein as a pin, is used to scan the surface of a sample, interacting with the sample at the atomic or nanoscale to produce high-resolution images.

[0095] The pin for AFM measurements may comprise a sharp point, for example, a point that ends in a single atom or a few atoms. This can ensure that the interaction with a sample surface is highly localized.

[0096] The AFM pin may be shaped like a pyramid or a cone, or may have a tapering to the sharp point at the end. This shape can allow for good resolution and may also provide structural support.

[0097] The presently disclosed AFM pin may be attached to a flexible cantilever, which can move up and down based on the interaction between the tip and the sample surface. The cantilever can be a thin rectangular or triangular beam. In some examples, the tip structure comprises a cantilever comprising the AFM pin. The upper side of the cantilever may be coated with a reflective layer (such as gold or aluminum). This can be used in an optical lever detection system where a laser beam is reflected off the cantilever's surface onto a photodiode. Changes in the angle of the reflected laser can indicate deflections of the cantilever.

[0098] The AFM pin may comprise or consist of a material selected from the group including silicon, silicon nitride, and diamond.

[0099] The presently disclosed kirigami device can initially have a planar configuration. When in use, the kirigami device may be converted into a 3D structure by folding, by applying a force, such that the kirigami device moves into an interlocking configuration. The resulting 3D kirigami device can have several applications such as AFM probes and drug delivery needles, resulting in an AFM probe and / or needles production that does not rely on cleanroom facilities, aiming to enhance cost efficiency, reduce complexity and time in manufacturing, reconfigurability, and biocompatibility.

[0100] Drug delivery

[0101] In one embodiment of the present disclosure, the kirigami device can be arranged for drug delivery. The kirigami device may, for example, comprise at least one tip structure arranged for the delivery of a pharmaceutical drug, such as through the epithelial layer of the skin. In one example, the kirigami device, including the tip structure, may comprise a pharmaceutical drug. The tip may have a jagged shape. In specific examples, the structure can comprise one or more electrodes.

[0102] The presently disclosed kirigami device may be arranged such that it can be transformed from an unfolded state, such as a planar configuration, into a 3D structure by applying an external force, whereby the kirigami device is moved from a planar configuration to an interlocking configuration.

[0103] The resulting 3D kirigami device can have several applications such as AFM probes, microneedles for drug delivery, and electrodes for measuring and / or providing current, such as electrical stimulation, to parts of the body, for example, the brain.

[0104] The kirigami device may serve as a simple and cost-effective means for fabricating, for example, an AFM probe and / or microneedles. Such fabrication might not rely on cleanroom facilities and / or advanced equipment, and could instead be produced by simple means. In one embodiment, the kirigami device may be produced by providing one or more cuts through a planar substrate, which may then be folded, for example by stretching, into an interlocking configuration.

[0105] Additionally, in one embodiment of the present disclosure, the kirigami device may comprise a tip structure arranged for piercing a part of a body tissue, such as a part of the skin, including the epithelial layer. The tip structure may also be referred to as a microneedle, needle, or bioneedle, and refers to one or more sharp structures arranged for piercing at least a part of a body tissue, such as a skin layer.

[0106] The tip structure can be arranged for drug delivery. The kirigami device may comprise at least one tip structure arranged for containing and / or delivering a pharmaceutical drug, such as through the epithelial layer of the skin. The tip structure may have an auxetic angle perpendicular to the uniaxial tension applied to the foldable substrate. In one embodiment of the present disclosure, the one or more tip structures may have a jagged shape.

[0107] Jagged-shaped needles may potentially increase the needle sharpness, reduce friction due to the reduced contact area, and anchor the surrounding soft tissue to reduce its deformation and displacement during insertion.

[0108] Transdermal sensing

[0109] Electrodes of the kirigami device can be combined with sensing electronics and used to monitor biomedical parameters when delivering therapeutic agents or drugs directly to specific areas, allowing for localized treatment and reduced systemic side effects. However, with conventional needles, it may not be possible to have multiple electrodes to deliver multiple therapeutic agents or drugs. Therefore, in one embodiment of the present disclosure, each tip structure can comprise one or more electrodes. The manufacturing process of such electrodes may be simple, attributed to the fact that the conducting material of the one or more electrodes can be deposited when the substrate is planar, such as in its planar configuration, either before or after making one or more discontinuous cuts in the planar substrate.

[0110] The terms electrode and electrodes are used interchangeably herein and refer to both a single electrode as well as a plurality of electrodes. For example, electrode as used herein may refer to a single electrode or a plurality of electrodes, including an array of electrodes, such as a 3D microelectrode array. In one example, the electrodes are microelectrodes, meaning that they have at least one dimension in the micron range, i.e., from 1 pm to 1 mm. Typically, at least the axial cross-sectional length, such as the diameter, is in the micron range.

[0111] In one embodiment of the present disclosure, the tip structure can comprise one or more electrodes, such as two electrodes, three electrodes, or four electrodes.

[0112] Additionally, the electrodes may be coated to increase biocompatibility, reduce reactivity, and increase conductivity. Therefore, the electrodes may comprise or consist of a coating of suitable material, such as gold.

[0113] In one embodiment of the present disclosure, the tip structure may comprise a waveguide. The tip can be an optical waveguide. An optical waveguide, as used herein, refers to a physical structure that guides electromagnetic waves, particularly light, from one point to another. Typically, the optical waveguide is arranged to trap and confine light in a way that allows it to propagate with minimal loss.

[0114] In one example, the tip structure can comprise one or more electrodes and / or one or more waveguides. For example, the tip structure may comprise a microelectrode array, such as a 3D microelectrode array, and one or more optical waveguides. In this way, the tip structure can be arranged, in an interlocking configuration, to provide photo and / or electrical stimulation for the brain.

[0115] Thus, in one example, the tip structure is arranged for photostimulation of a part of a body, such as in optogenetics and / or photostimulation by caged compounds.

[0116] Alternatively, or additionally, the tip structure may be arranged for electrical stimulation of a part of a body, such as deep brain stimulation. The part of the body may be, for example, the brain.

[0117] In one embodiment of the present disclosure, the kirigami device, including the tip structure, may comprise one or more electrodes, such as a microelectrode array, wherein the kirigami device is arranged to provide electrical stimulation, for example, to neurons or cardiomyocytes, such as in the interlocking configuration and / or when implanted. Alternatively, or additionally, the presently disclosed kirigami device, or any of the other examples disclosed herein, could comprise one or more waveguides, such as optical waveguides at or near the tip structure. Thus, the kirigami device may, for example, be arranged to provide light stimulation, for example, to neuron cells, such as in the interlocking configuration. By combining optical waveguides and electrodes, the kirigami device may be arranged to provide electrical, optical, and / or mechanical stimulation, such as to cells, for example, neurons or cardiomyocytes. The kirigami device may, for example, comprise one or more optical waveguides arranged to provide optical stimulation, such as to cells. Additionally, or alternatively, the kirigami device may comprise one or more electrodes and be arranged to provide electrode stimulation, such as to cells. Further, the kirigami device may be arranged to provide mechanical stimulation, possibly simultaneous to providing electrical and / or optical stimulation, such as to cells.

[0118] While kirigami devices can have several applications and modalities with reference to various embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the teachings herein. In addition, many modifications can be made to adapt the kirigami device disclosed herein to a particular situation without departing from the scope thereof. Therefore, it is intended that the claims should not be limited to the particular embodiments disclosed herein.

[0119] Detailed description of drawings

[0120] The invention will in the following be described in greater detail with reference to the accompanying drawings. The drawings are exemplary and are intended to illustrate some of the features of the presently disclosed kirigami device and related methods, and are not to be construed as limiting to the presently disclosed invention.

[0121] Fig. 1 is a schematic illustration providing a top-down view of a kirigami device (1) according to one embodiment of the present disclosure. The kirigami device comprises a foldable substrate (9). The foldable substrate comprises a plurality of discontinuous cuts (6), It also comprises an interlocking mechanism that comprises two components (2), an engaging element and a retaining element. The foldable substrate (9) also comprises a first section (11) and a second section (12), divided by a symmetry axis A. The kirigami device further comprises a plurality of substrate areas, including a rectangular section (7) and a triangular section (8). The triangular section / part comprises a tip structure (4).

[0122] Fig.2 is a schematic illustration showing a top view of the kirigami device (1) according to one embodiment of the present disclosure. The foldable substrate (9) is shown having an initial bend / fold along the central axis AA shown in Fig. 1. Additionally, the figure shows one of the components (2) of the interlocking mechanism, the tip structure (4), and the plurality of discontinuous cuts (6).

[0123] Fig. 3 is a schematic illustration providing the bottom view of the kirigami device (1) according to one embodiment of the present disclosure in the interlocking configuration. It can be seen the fully folded foldable substrate (9), the one or more cuts (6), and the tip structure (4). Additionally, the tip structure comprises a pin, which may be for example a carbon nanotube (10). Lastly, the figure shows the two components (2) of the interlocking mechanism (3) when engaged.

[0124] Fig 4 is a schematic illustration showing a cutaway illustration of the interlocking mechanism (3) of a kirigami device (1) according to an embodiment of the present disclosure, in the interlocking configuration, such that the components of the interlocking mechanisms are engaged. In this specific example, the engaging element and the retaining elements are provided as two hooks, having a curved shape, such that they can engage with each other, thereby retaining the kirigami device in the interlocking configuration.

[0125] Fig 5 is a schematic illustration providing a schematic of the top view of the kirigami device (1). Here, it can be seen the fully folded foldable substrate (9), the one or more cuts (6), and the tip (4) with a carbon nanotube sharp tip deposition (10). Here, the kirigami device (1) is shown in the interlocking configuration, and may for example be used as an AFM probe.

[0126] Fig. 6 is a schematic illustration showing one embodiment of the presently disclosed kirigami device (1). This example features a generally rectangular foldable substrate (9). Further, the presently disclosed kirigami device comprises two components (2a, 2b) of the interlocking mechanism. One of the components (2) of the interlocking mechanism is an engaging element (2a), and the second component is a retaining element (2b). The engaging element (2a) comprises a widening, such as having a T shape, while the retaining element (2b) has an aperture arranged to engage with the engaging element. In particular, the example shows a retaining element having a constriction. Moreover, Fig. 6 shows a plurality of discontinuous cuts (6). A straight cut separates the rectangular foldable structure into two sections (a first section (11) and a second section (12)). This straight cut is parallel to the shortest length of the rectangular folded substrate. Additionally, the first section (11) of the foldable substrate includes a discontinuous cut resulting in a triangular substrate area, arranged to extend away from the rest of the kirigami device at an angle. Further, this triangular substrate area comprises a tip structure (4), which may, for example, be used as an AFM probe or a microneedle.

[0127] Fig. 7 is a schematic illustration showing one embodiment of the presently disclosed kirigami device (1). It displays the rectangular foldable substrate (9) and the two components (2) of the interlocking mechanism. One of the components (2) of the interlocking mechanism is an engaging element (2a), and the second component is a retaining element (2b). The engaging element (2a) comprises two hook elements, and the retaining element (2a) is an adjustable element comprising multiple apertures along the longest side of the rectangular foldable substrate (9), particularly within the second section (12) of the rectangular foldable substrate (9). Moreover, Fig. 7 shows a plurality of straight cuts (6). A straight cut separates the rectangular foldable structure into two sections (11 and 12). This straight cut is parallel to the shortest length of the rectangular folded substrate. Additionally, section one (11) of the foldable substrate includes a straight cut forming a triangular shape (8), which provides a tip structure (4) for an AFM probe. While the example shown comprises a pair of engaging elements and pairs of retaining elements, any number of engaging elements may be arranged to engage with any number of retaining elements. Typically, a plurality of retaining elements are located at different distances from the engaging elements in the planar configuration, for adjusting the angle of the tip structure when in the interlocking configuration.

[0128] Fig. 8A is a schematic illustration showing one embodiment of the disclosed kirigami device (1). It displays a foldable substrate (9) with a plurality of discontinuous cuts (6) and the two components (2) of the interlocking mechanism. One of the components (2) of the interlocking mechanism is an engaging element (2a), and the second component is a retaining element (2b). The engaging element (2a) comprises two hook elements, and the retaining element (2b) is part of the tip structure (4) of the foldable substrate (9). The kirigami device comprises a tip structure (4) arranged at an angle with respect to the first plane, when in the interlocking configuration (Fig. 8B).

[0129] Fig. 9A is a schematic illustration showing the kirigami device (1) in its planar configuration, featuring a foldable substrate (9) with a plurality of tip structures, such as an array of needles (13). Fig. 9B shows a close-up of one jagged needle tip (14), indicating the force direction and the folding of the substrate as the force is applied. Fig. 9C shows the jagged needle tip (14) fully assembled, with a reservoir (15) to hold, for example, a pharmaceutical agent or drug. Fig. 9C shows the fully assembled jagged needle (14) from a top view, with the tip side opening (16) visible.

[0130] Fig. 10A is a schematic illustration showing the kirigami device (1) in its planar configuration. The figure shows a foldable substrate (9) with a plurality of discontinuous cuts (6) and an array of needles (13). The figure provides a close-up of a jagged needle (14) containing a plurality of electrodes (17-20), specifically, four gold-coated electrodes (17-20). Additionally, the figure shows the arrangement of contact pads (20) of the electrodes, particularly of two electrodes (18 and 20), as well as a plurality of discontinuous cuts (6). Fig. 10B shows a close-up of one jagged needle (14) fully assembled, showing two electrodes (18, 20) and the tip side opening of the needle (16). The dotted line indicates that the electrodes are provided on the bottom side of the structure (the side not facing the viewer). The folding mechanism realizes a two- sided electrical connection, which is typically challenging to produce at the microscale. Alternatively or in addition to electrodes, the presently disclosed kirigami device, or any of the other examples disclosed herein, could comprise one or more waveguides, such as waveguides at or near the tip structure. Thus, the kirigami device may, for example, be arranged to provide light stimulation, for example to neuron cells, such as in the interlocking configuration. Simultaneously, or alternatively, the kirigami device, such as the tip structure, may comprise one or more electrodes, such as a microelectrode array, for providing electrical stimulation. By combining optical waveguides and electrodes, the kirigami device may be arranged to provide electrical, optical, and / or mechanical stimulation, such as to cells, for example, neurons or cardiomyocytes. The kirigami device may, for example, comprise one or more optical waveguides arranged to provide optical stimulation, such as to cells. Additionally, or alternatively, the kirigami device may comprise one or more electrodes and be arranged to provide electrical stimulation, such as to cells. Further, the kirigami device may be arranged to provide mechanical stimulation, possibly simultaneous to providing electrical and / or optical stimulation, such as to cells.

[0131] Fig. 11A is a schematic illustration showing the kirigami device (1) in its planar configuration. The figure shows a foldable substrate (9) with a plurality of discontinuous cuts (6) as well as an array of needles (13). Fig. 11 B shows an array of needles (13) after the foldable substrate has been subjected to a stretching force. Additionally, the smooth tips (21) of the needles are shown. Fig. 12A is a schematic illustration showing the kirigami device (1) in its planar configuration. The figure shows a foldable substrate (9) with a plurality of discontinuous cuts (6). It also specifically shows a foldable substrate (9) with an array of needles (13). Fig. 12B shows an array of needles (13) after the foldable substrate has been subjected to a stretching force. Fig. 12C shows a close-up of a jagged tip (14) of one needle of the array (13).

[0132] Figure reference list

[0133] 1 kirigami device

[0134] 2 component

[0135] 3 interlocking mechanism

[0136] 4 tip structure

[0137] 6 plurality of discontinuous cuts

[0138] 7 rectangular section

[0139] 8 triangular section

[0140] 9 foldable substrate

[0141] 10 pin

[0142] 11 first section

[0143] 12 second section

[0144] 13 tip structures / array of needles

[0145] 14 tip structure / jagged needle tip

[0146] 15 reservoir

[0147] 16 tip side opening

[0148] 17 electrode

[0149] 18 electrode

[0150] 19 electrode

[0151] 20 electrode

[0152] 21 tip structure / smooth needle tip Items

[0153] 1. A kirigami device comprising a foldable substrate, the substrate comprising:

[0154] • one or more discontinuous cuts arranged such that the substrate may be moved from a planar configuration wherein the substrate extends substantially in a first plane, to an interlocking configuration wherein the substrate forms an expanded structure extending in three dimensions; and

[0155] • an interlocking mechanism comprising a first component and a second component, wherein the first component is disengaged from the second component in the planar configuration, and wherein the first component is engaged with the second component in the interlocking configuration, wherein the interlocking mechanism is arranged to retain the substrate in the interlocking configuration.

[0156] 2. The kirigami device according to any of the preceding items, wherein the foldable substrate comprises at least one tip structure, such as a plurality of tip structures.

[0157] 3. The kirigami device according to item 2, wherein the kirigami device is arranged such that, in the interlocking configuration, the tip structure is arranged at an angle with respect to the first plane and / or with respect to a general plane of the rest of the kirigami device.

[0158] 4. The kirigami device according to any one of items 2-3, wherein the kirigami device is arranged such that, in the interlocking configuration, the tip structure is arranged at an angle with respect to the rest of the foldable substrate.

[0159] 5. The kirigami device according to any one of items 2-4, wherein the foldable substrate is arranged such that, when moving said structure from the planar configuration to the interlocking configuration, at least a part of the tip structure is moved out of the first plane of the foldable substrate.

[0160] 6. The kirigami device according to any of the preceding items, wherein the discontinuous cuts divide the foldable substrate into a plurality of substrate areas.

[0161] 7. The kirigami device according to item 6, wherein the substrate areas comprises at least two different shapes arranged adjacent to each other. The kirigami device according to any of items 6-7, wherein the foldable substrate comprises a substrate area having a rectangular shape. The kirigami device according to any of items 6-8, wherein the foldable substrate comprises a substrate area having a triangular shape. The kirigami device according to items 9, wherein the triangular shape is an isosceles or equilateral triangle. The kirigami device according to any one of the preceding items, wherein the foldable substrate comprises an aperture. The kirigami device according to any of the preceding items, wherein the foldable substrate is arranged such that it can be moved from the planar configuration to the interlocking configuration upon stretching of the foldable substrate, such as in stretching of the foldable substrate in the first plane, such as in a direction parallel to the first plane. The kirigami device according to any of the preceding items, wherein the first component is distanced from the second component in the planar configuration. The kirigami device according to any of the preceding items, wherein the first component and the second component of the interlocking mechanism are located at opposite parts / edges of the foldable structure, when the foldable structure is in the planar configuration. The kirigami device according to any one of the preceding items, wherein the interlocking mechanism automatically engages when the foldable substrate is moved from the planar configuration to the interlocking configuration. The kirigami device according to any of the preceding items, wherein the first component is interlocked with the second component in the interlocking configuration. The kirigami device according to any of the preceding items, wherein the foldable substrate comprises a plurality of interlocking mechanisms. The kirigami device according to any of the preceding items, wherein the first component comprises an engaging element and the second component comprises a retaining element, wherein the engaging element is arranged to engage with the retaining element when the foldable substrate is in the interlocking configuration. The kirigami device according to item 18, wherein the interlocking mechanism is arranged such that, when the engaging element is engaged with the retaining element, it retains the foldable substrate in the interlocking configuration. The kirigami device according to any one of items 18-19, wherein the engaging element is a hook element, a widening, a tab, and / or a protrusion. The kirigami device according to any one of items 18-20, wherein the retaining element is a hook element, an aperture, a hole, a notch, and / or a recess. The kirigami device according to any of the preceding items, wherein the first component and the second component of the interlocking mechanism comprises a hook element. The kirigami device according to item 22, wherein the hook element of the interlocking mechanism comprises a curved shape, such as a J-shape / U-shape. The kirigami device according to any of the preceding items, wherein the interlocking mechanism is arranged to facilitate connection between different parts of the foldable substrate such that the stability of the kirigami device is increased in the interlocking configuration, with respect to the planar configuration. The kirigami device according to any of the preceding items, wherein the kirigami device is an AFM probe. The kirigami device according to item 25, wherein the foldable substrate comprises one or more pins. 27. The kirigami device according to item 26, wherein the pin is arranged for AFM measurements

[0162] 28. The kirigami device according to any one of items 26-27, wherein the pin is made of silicon, silicon nitride, metal, mineral, and / or a carbonaceous material, such as carbon nanotube.

[0163] 29. The kirigami device according to any one of items 26-28, wherein the pin has a diameter in the range of from 10 nm to 40 nm, more preferably from 5 nm to 20 nm and even more preferably from 1 nm to 5 nm.

[0164] 30. The kirigami device according to any one of items 1-24, wherein the kirigami device is arranged for drug delivery.

[0165] 31. The kirigami device according to item 30, wherein the kirigami device comprises at least one tip structure arranged for delivery of a pharmaceutical drug, such as through the epithelial layer of skin.

[0166] 32. The kirigami device according to item 31 , wherein the tip structure comprises a pharmaceutical drug, such as a pharmaceutical drug coating or encapsulation.

[0167] 33. The kirigami device according to any one of the preceding items, wherein the tip structure comprises a jagged shape.

[0168] 34. The kirigami device according to any one of the preceding items, wherein the tip structure(s) comprises one or more electrodes, such as independent electrodes, and / or wherein the tip structure comprises one or more waveguides.

[0169] 35. The kirigami device according to any one of the preceding items, wherein the kirigami device, such as the one or more tip structures, is arranged to provide an electrical stimulation, an optical stimulation (e.g., photonic) and / or a mechanical stimulation.

[0170] 36. A method of manufacturing a kirigami device, the method comprising: • providing a foldable substrate; and

[0171] • forming, in the foldable substrate, one or more discontinuous cuts and an interlocking mechanism. 37. The method according to item 36, wherein the kirigami device is arranged according to any one of items 1-35

Claims

Claims1 . A kirigami device comprising a foldable substrate, the substrate comprising:• one or more discontinuous cuts arranged such that the substrate may be moved from a planar configuration, wherein the substrate extends substantially in a first plane, to an interlocking configuration, wherein the substrate forms an expanded structure extending in three dimensions; and• an interlocking mechanism comprising a first component and a second component, wherein the first component is disengaged from the second component in the planar configuration, and wherein the first component is engaged with the second component in the interlocking configuration, wherein the interlocking mechanism is arranged to retain the substrate in the interlocking configuration.

2. The kirigami device according to any of the preceding claims, wherein the foldable substrate comprises one or more tip structures.

3. The kirigami device according to claim 2, wherein each tip structure is arranged at an angle with respect to the first plane and / or with respect to a general plane of the rest of the kirigami device when in the interlocking configuration.

4. The kirigami device according to any one of claims 2-3, wherein each tip structure is arranged at an angle with respect to the rest of the foldable substrate in the interlocking configuration.

5. The kirigami device according to any one of claims 2-4, wherein the foldable substrate is arranged such that, when moving said structure from the planar configuration to the interlocking configuration, at least a part of each tip structure is moved out of the first plane of the foldable substrate.

6. The kirigami device according to any of the preceding claims, wherein the discontinuous cuts divide the foldable substrate into a plurality of substrate areas.

7. The kirigami device according to claim 6, wherein the substrate areas comprise at least two different shapes arranged adjacent to each other.

8. The kirigami device according to any of claims 6-7, wherein the foldable substrate comprises a substrate area having a rectangular shape.

9. The kirigami device according to any of claims 6-8, wherein the foldable substrate comprises a substrate area having a triangular shape.

10. The kirigami device according to claims 9, wherein the triangular shape is an isosceles or equilateral triangle.11 . The kirigami device according to any one of the preceding claims, wherein the foldable substrate comprises an aperture.

12. The kirigami device according to any of the preceding claims, wherein the foldable substrate is arranged such that it can be moved from the planar configuration to the interlocking configuration upon stretching of the foldable substrate, such as in stretching of the foldable substrate in the first plane, such as in a direction parallel to the first plane.

13. The kirigami device according to any of the preceding claims, wherein the first component is distanced from the second component in the planar configuration.

14. The kirigami device according to any of the preceding claims, wherein the first component and the second component of the interlocking mechanism are located at opposite parts / edges of the foldable structure, when the foldable structure is in the planar configuration.

15. The kirigami device according to any one of the preceding claims, wherein the interlocking mechanism automatically engages when the foldable substrate is moved from the planar configuration to the interlocking configuration.

16. The kirigami device according to any of the preceding claims, wherein the first component is interlocked with the second component in the interlocking configuration.

17. The kirigami device according to any of the preceding claims, wherein the foldable substrate comprises a plurality of interlocking mechanisms.

18. The kirigami device according to any of the preceding claims, wherein the first component comprises an engaging element and the second component comprises a retaining element, wherein the engaging element is arranged to engage with the retaining element when the foldable substrate is in the interlocking configuration.

19. The kirigami device according to claim 18, wherein the interlocking mechanism is arranged such that, when the engaging element is engaged with the retaining element, it retains the foldable substrate in the interlocking configuration.

20. The kirigami device according to any one of claims 18-19, wherein the engaging element is a hook element, a widening, a tab, and / or a protrusion.

21. The kirigami device according to any one of claims 18-20, wherein the retaining element is a hook element, an aperture, a hole, a notch, and / or a recess.

22. The kirigami device according to claim 1-19, wherein the first component and the second component of the interlocking mechanism each comprise a hook element.

23. The kirigami device according to any one of claims 20-22, wherein the one or more hook elements each comprise a bent, curved, or angled shape, such as a J-shape, U-shape, or V-shape.

24. The kirigami device according to any of the preceding claims, wherein the interlocking mechanism is arranged to facilitate connection between different parts of the foldable substrate such that the stability of the kirigami device is increased in the interlocking configuration, with respect to the planar configuration.

25. The kirigami device according to any of the preceding claims, wherein the kirigami device is an AFM probe.

26. The kirigami device according to any of the preceding claims, wherein the foldable substrate comprises one or more pins.

27. The kirigami device according to claim 26, wherein the pin is arranged for AFM measurements28. The kirigami device according to any one of claims 26-27, wherein the pin is made of silicon, silicon nitride, metal, mineral, and / or a carbonaceous material, such as carbon nanotube.

29. The kirigami device according to any one of claims 26-28, wherein the pin has a diameter in the range of from 10 nm to 40 nm, more preferably from 5 nm to 20 nm and even more preferably from 1 nm to 5 nm.

30. The kirigami device according to any one of claims 1-24, wherein the kirigami device is arranged for drug delivery.

31. The kirigami device according to claim 30, wherein the kirigami device comprises at least one tip structure arranged for delivery of a pharmaceutical drug, such as through the epithelial layer of skin.

32. The kirigami device according to claim 31, wherein the tip structure comprises a pharmaceutical drug, such as a pharmaceutical drug coating or encapsulation.

33. The kirigami device according to any one of the preceding claims, wherein the tip structure comprises a jagged shape.

34. The kirigami device according to any one of the preceding claims, wherein the tip structure(s) comprises one or more electrodes, such as independent electrodes, and / or wherein the tip structure comprises one or more waveguides.

35. The kirigami device according to any one of the preceding claims, wherein the kirigami device, such as the one or more tip structures, is arranged to provide an electrical stimulation, an optical stimulation (e.g., photonic) and / or a mechanical stimulation.

36. A method of manufacturing a kirigami device, the method comprising:• providing a foldable substrate; and• forming, in the foldable substrate, one or more discontinuous cuts and an interlocking mechanism.

37. The method according to claim 36, wherein the kirigami device is arranged according to any one of claims 1-35.

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