Decoding optical signals from the surface of array elements

Abstract

A system and method for interpreting an optical characterization inspection performed with a set of optical devices (1, 1a, 1b, 1c). Each device includes one or more arrays (21-26) of optical metasurface structures (12) and has arrays (21-26) customized to have different characteristics that make them different from each other. First data and second data capturing the physical fingerprint of each device (1) and the result of the optical characterization inspection performed with each device (1) are accessed separately. The result of the inspection performed is affected by the corresponding different characteristics of the array (21-26). Based on the accessed first data, each device (1) is identified, which makes it possible to obtain a readout key associated with the identified device. The readout key interprets the corresponding characteristic among the different characteristics. Finally, the second data is interpreted based on the obtained readout key to clarify the result of the optical characterization inspection. The present invention also relates to a related computer program product.

Description

Background Art

[0001] The present disclosure generally relates to techniques for interpreting optical characterization inspections performed with various optical devices. In particular, the present invention relates to methods based on devices having arrays of optical metasurface structures, wherein these arrays are customized to have different properties that act as configuration secrets, and wherein the physical fingerprint of the device is additionally utilized to authenticate the device. Summary of the Invention

[0002] According to a first aspect, a method for inspecting a group of optical devices is provided. Each device includes one or more arrays of optical metasurface structures. The devices are customized so that their corresponding arrays have different characteristics. The optical devices are different from each other due to the different characteristics of the arrays. The method includes a series of steps performed for each device in the group. First, (for example, by a server) first data and second data that capture the physical fingerprint of each device and the results of an optical characterization inspection performed with each device are accessed separately. Because the devices have different characteristics, the results of the inspections performed with them are affected by the corresponding different characteristics of the arrays. That is, the results of the characterization inspection performed with a given device in the group are affected by corresponding characteristics among the different characteristics. Each device is identified based on the accessed first data, which in turn makes it possible to obtain a readout key associated with the identified device. The readout key explains the corresponding characteristics among the different characteristics. Finally, the second data is interpreted based on the obtained readout key to clarify the results of the optical characterization inspection. The results can then be provided to the inspection device.

[0003] An optical characterization inspection performed using an optical device comprising different arrays may result in the formation of different or combined optical signals (due to the different arrays), all of which may accordingly influence or in some way form part of the result of the inspection.

[0004] This method allows for two levels of security. First, the physical fingerprint of each optical device is difficult (if not impossible) to clone, allowing each optical device to be unambiguously identified. Second, readout keys can only be obtained for those devices that have been properly identified. Furthermore, the user of the device may be authenticated during this process. Thus, only legitimate devices (and possibly authenticated users) can, for example, have a server properly interpret the results or provide analytical information for interpreting data obtained using a customized optical device.

[0005] In some embodiments, the result is influenced by both the corresponding one of the different characteristics and the physical fingerprint of each device. In this case, the corresponding readout keys may have been designed to account for both the corresponding one of the different characteristics and the physical fingerprint of each device. In addition, accessing the first data and the second data may first include receiving characterization data. In this case, given that each device is identified, the first and second data are determined based on the received characterization data to obtain the associated readout keys and interpret the second data based on the obtained readout keys. Relying on a single characterization step (from which both types of data are obtained) can be advantageous in some applications because it can simplify operations performed locally (e.g., at the point of care).

[0006] Preferably, the physical fingerprint is an unclonable property of one or more arrays of each device. An unclonable property, such as a physical unclonable property, makes it more difficult (or even practically impossible) for a malicious user to replicate an array of optical devices. In a variant, one can rely on embedded security features rather than the unclonable property. A further variant can utilize the unclonable property of, or embedded security features within, a physical anchor attached to the optical device.

[0007] In some embodiments, each of the optical devices in the group includes two or more metasurface structure arrays that together impart different properties to the optical device, making the devices in the group distinct from one another. Thus, the properties can be more easily customized to result in different (but predictable) properties and, therefore, different characterization results when performing an optical characterization inspection. Nevertheless, an appropriate readout key can be assigned to the optical device, wherein such a key includes a code, function, etc., by which the inspection results can be correctly interpreted.

[0008] Preferably, the element surface structure of at least one array of each device is coated with a substance for selectively binding analytes, wherein the substance forms the corresponding functionalized pattern of the array of the device. The result of the characterization inspection as captured by the second data (for each device) is affected by both the element surface structure of the corresponding array (for each device) and the corresponding functionalized pattern in the functionalized pattern. The latter may produce different light signals, all of which constitute a part of the result (for each device). Therefore, in this case, the readout key also interprets the corresponding functionalized pattern in the functionalized pattern.

[0009] Preferably, these substances comprise molecular receptors for selectively binding these analytes.The elemental surface structures of at least one array of each device are coated with molecular receptors so as to functionalize the array of said device according to a corresponding functionalization pattern formed by said molecular receptors.

[0010] For example, two or more arrays of each device can be coated with different types of molecular receptors for selectively combining different types of analytes. Receptors can, for example, be formed into molecular compounds fixed on the surface of one or more meta-surface structures. Each molecular compound can include several parts, including a first part anchored to the surface and a second part that is chemically connected to the receptor of the first anchoring part via a main chain. These several parts can advantageously include a third part, which is a protective part for acetylene, wherein the protective part is bound to the acetylene unit of the main chain by an electrochemically breakable bond. In that case, the method can further include deprotecting the acetylene units of the molecular compound main chains by electrochemically cracking these protective parts before these molecular receptors are bound to the deprotected acetylene units. Because the initially protected acetylene units are fixed on the surface, the deprotection mechanism causes the surface of acetylene functionalization. Therefore, it provides a chemically flexible attachment, which makes it possible to subsequently bind a variety of functional receptors to the compounds of these crackings. Together with electrochemically addressable deprotection, site-selective functionalization can be carried out to produce a meta-surface device with different substances (patterns).

[0011] In some embodiments, the results of the optical characterization include optical data representing a spectral response of each device (e.g., a spectral response of each array in an array of each device). Preferably, the method further comprises: for each device and before accessing the first and second data, performing an optical characterization by illuminating each array of each device with electromagnetic radiation at a frequency that matches the resonant frequency of the meta-surface structures of the array in the absence of the analyte. The spectral response can be, for example, a response to electromagnetic radiation transmitted through each device, whereby the spectral response reflects changes in the absorption resonance caused by effective changes in the dielectric environment of the meta-surface structures in one or more arrays of the device.

[0012] In some embodiments, the method is performed (at least in part) at a server in data communication with a set of client devices. In such cases, the method may further include: for each device and before accessing the first data and the second data, receiving data from one of the client devices paired with each optical device, whereby the first data and the second data can be accessed by the server based on the received data, so that the server identifies each device based on the accessed first data and interprets the second data according to the correspondingly obtained readout key. In a variant, the interpretation is performed on the client side.

[0013] The method may further include, after each device has been identified and the second data has been interpreted to clarify the results of the optical characterization inspection, sending a message to one of the client devices, the message including information regarding the clarified results. In a variation, the message may include information for interpreting the optical data, thereby enabling the results to be generated by the client device itself.

[0014] In some embodiments, the method further includes: for each device in the group and before accessing the first data and the second data for any device in the group: manufacturing each device so that one or more arrays of each device have corresponding ones of the different characteristics; and associating a readout key of the corresponding ones of the different characteristics with an identifier of each device.

[0015] In some embodiments, the method further includes: after manufacturing each device and before accessing the first data and the second data of any device in the group, reading the physical fingerprint of each device to obtain a digital fingerprint corresponding to the physical fingerprint, and associating the digital fingerprint with an identifier of each device.

[0016] In some embodiments, each array of each of the devices comprises a pattern of repeating units of meta-surface structures, wherein each unit each comprises at least one (e.g., two) meta-surface structures. The meta-surface structures are preferably formed as semiconductor layer structures arranged on top of a substrate. The substrate may, for example, be transparent to allow optical characterization inspection in transmission. The semiconductor structures may each have an average lateral dimension between 1 nm and 500 nm, the lateral dimension being measured parallel to the main surface of the substrate. Preferably, the semiconductor structures each have an average vertical dimension between 10 nm and 500 nm, and the standard deviation of the vertical dimension is less than 5 nm, the vertical dimension being measured perpendicular to the main surface of the substrate.

[0017] According to another aspect, a computer program product for interpreting an optical characterization inspection performed using a set of devices as described above is disclosed. Specifically, each device includes one or more arrays of electromagnetic surface structures, and the devices are customized so that their respective arrays have different characteristics. The computer program product includes a computer-readable storage medium having program instructions embodied therein, wherein the program instructions are executable by a processing device to cause the processing device to perform the steps of the method according to the present invention for each device in the set. Specifically, the program instructions cause the processing device to access first data and second data, identify each device based on the accessed first data to obtain a readout key, and interpret the second data based on the readout key to interpret the results of the optical characterization inspection, as explained above.

[0018] The method and computer program product will now be described, by way of non-limiting example, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings are used to further illustrate various embodiments and to explain all the various principles and advantages of the present disclosure, wherein the same reference numerals represent the same or functionally similar elements throughout the individual views, and are incorporated into and form a part of this specification together with the following detailed description).

[0020] Figure 1 is a block diagram schematically illustrating components of a system involving an optical device having an array of functionalized metasurface structures, an optical detector, a smartphone connected to the detector, and a server connected to the smartphone, for interpreting optical characterization inspections as performed using the optical device in some embodiments. In a variant, the mobile phone is used as the optical detector, thereby using the smartphone's integrated camera;

[0021] Figure 2 is another block diagram schematically illustrating a server interacting with several optical devices (having different array characteristics) via respectively connected smartphones to interpret optical characterization inspections performed with the optical devices, as in some embodiments;

[0022] Figure 3A and Figure 3B is a schematic top view of an optical device having different array characteristics (represented by different pattern fills), as in some embodiments;

[0023] Figure 4 is a sequence diagram illustrating how metasurface structures of an optical device array can be coated with molecular receptors to selectively bind analytes to form a given functionalized pattern of the optical device array, according to an embodiment;

[0024] Figure 5 is a flow chart illustrating high-level steps of a method for interpreting an optical characterization inspection performed with a set of optical devices, wherein first and second data are obtained as a result of respective characterization (or detection) steps. Each device is identified based on the first data to obtain an associated readout key, which is then used, as in some embodiments, to interpret the second data;

[0025] Figure 6 is similar to Figure 5 Flowchart of , except that a single characterization step is required, thereby producing the characterization data from which the first and second data are extracted as in some embodiments;

[0026] Figure 7A —7C shows the wavelength bins (i.e., intervals, see Figure 7A), which is used to measure the optical wavelength resonance obtained due to the metasurface structure array. With a view to later certifying the optical device (for example, by the manufacturer before or while commissioning the optical device) the obtained signal can be recorded and stored ( Figure 7B ). The signal subsequently obtained by the end user of the device allows identification of the corresponding bin, which in turn allows authentication of the optical device ( Figure 7C ). The corresponding readout key may be identified accordingly, which is ultimately used to interpret the signal value in some embodiments;

[0027] Figure 8A A cloud computing environment according to an embodiment of the present invention is described;

[0028] Figure 8B An abstract model layer according to an embodiment of the present invention is described.

[0029] The accompanying drawings show simplified representations of devices or parts thereof as involved in some embodiments. The technical features depicted in the accompanying drawings are not necessarily drawn to scale. Similar or functionally similar elements in the accompanying drawings are assigned the same reference numerals unless otherwise indicated. DETAILED DESCRIPTION

[0030] Ensuring product authenticity is a requirement across multiple industries, particularly where there is a risk of harm or other adverse consequences from the use of counterfeit or used products. While tracking and tracing the logical and physical route, condition, and chain of custody (or ownership) of goods throughout the supply chain and asset lifecycle is essential, it is also desirable to maintain a close link between the physical object and its digital representation. Blockchain (or any other digital track and trace solution) is often insufficient to prove authenticity, correctness, and / or legitimacy within the supply chain or throughout the product lifecycle, such as an unbroken chain of custody. Typically, such attributes can only be established when trust can be extended to the physical domain. Therefore, it is necessary to tie the physical object to the associated digital record.

[0031] Typically, objects are associated with digital records through unique identifiers (UIDs), which represent individual objects or a class of objects by model, batch, production site, manufacturer, etc. The UID is typically printed, embossed, or attached as a label to the object or its packaging. Most UIDs can be easily copied and, for example, assigned to illegal clones of an object. Therefore, identifiers alone cannot uniquely and securely identify (i.e., thereby authenticate) an object.

[0032] The concept of crypto-anchors is introduced to address this problem. Crypto-anchors leverage a set of properties of physical objects to securely associate them with a UID. These properties encompass physical fingerprints (e.g., uncontrollable aspects such as manufacturing inaccuracies and material composition variations), embedded security features (e.g., tunable inherent material properties and material functionalization), and configuration secrets (e.g., key-based).

[0033] In addition, optical metasurface structures are an emerging class of planar optical elements that have applications in various areas due to their high sensitivity to changes in their local dielectric environment. Metasurface structures can be made of metals or dielectric materials, for example. Such elements allow light to be manipulated below the diffraction limit in a very efficient manner. Applications include electromagnetic field enhancement, polarization change, spatial light bending, spectral filtering, narrowband absorption, etc. Metasurfaces tailored to operate in the visible and near-infrared regions of the electromagnetic spectrum have nanometer-sized dimensions, typically ranging from tens of nanometers to 100 nanometers, or even smaller. The operation of such structures mainly depends on the resonant conditions of incident light with a specific wavelength.

[0034] For example, the absorption resonance shift can be measured. This change can be used for compound selective detection, for example by functionalizing the metasurface with a molecular receptor compound that allows selective binding of the analyte, thereby allowing the desired dielectric change. Due to the narrow spectral properties (e.g., absorption dips), the response of the device can be read not only using laboratory instruments (e.g., using a spectrometer or laser-based system), but also using a readout of a desktop device using a single spectral narrow light source combined with, for example, a small CMOS imager. For example, one might expect to implement this technology on an IoT device or mobile phone connected to a cloud application, so that the cloud application is available to individuals for mobile or home use. However, scenarios involving distributed devices or mobile phones also make it more difficult to track the authenticity of the product, and therefore require additional security measures.

[0035] The following description is structured as follows. First, general embodiments and advanced variants are described (Section 1). The next section (Section 2) covers specific embodiments (Section 2.1), preferred manufacturing methods (Section 2.2), and technical implementation details regarding computer program products (Section 2.3) and computerized devices (Section 2.4) used in some embodiments.

[0036] The method of the present invention and its variants are collectively referred to as "the present method". All reference numerals in the form of "Sij" refer to Figure 5 and Figure 6 The present invention provides method steps of flowcharts of the present invention, while numerical reference numerals indicate devices, physical parts or components as involved in some embodiments.

[0037] Section 1 General Examples and Advanced Variants

[0038] refer to Figure 1 、 Figure 2 、 Figure 5 and Figure 6 , firstly aspects are described relating to a method of interpreting an optical characterization inspection performed with a set of optical devices 1 , 1 a - 1 c .

[0039] Each device comprises one or more arrays 21-26 of optical metasurface structures 12 (also referred to in the literature as electromagnetic metasurface structures). In the following text, such structures 12 are sometimes referred to as "metasurfaces". In this document, such metasurface structures can be made of dielectric materials, semiconductor materials (such as silicon) or metals. Preferably, semiconductors, such as silicon, are used; the metasurface structures are preferably manufactured using an indirect transfer process as described in Section 2.2, which produces precise and clean metasurface structures. As is known per se, such metasurface structures are arranged according to a given in-plane pattern. In application, the optical device may comprise a single array of metasurface structures. However, as described below with reference to Figures 2 to 4 In some of the described embodiments, each optical device may comprise several metasurface arrays.The present optical devices 1 , 1a - 1c are preferably manufactured as sensing devices, as described in detail in section 2.1.

[0040] The optical devices 1, 1a-1c in the set are custom made; their respective arrays 21-26 have different characteristics. The different types of characteristics of the arrays can be used to differentiate between the devices, as will be discussed in detail later.

[0041] The method involves a series of steps that are performed for each optical device in the group. In the following, these steps are often described with respect to a given device 1. However, similar steps are performed for each device in the group, and these similar steps are generally performed in an independent manner, and therefore in an asynchronous manner.

[0042] First, the first data and the second data need to be transmitted by the server 300 ( Figure 1 )Access S31, S31a( Figure 5 ). The first data captures the physical fingerprint of a given device 1, while the second data reflects the use of the device 1 to perform S25 ( Figure 5 ) is the result of an optical characterization inspection of the array of the device 1. The result is affected by the specific characteristics of the array of the device 1. In this context, optical characterization inspection refers to an inspection involving the interaction of electromagnetic waves (not necessarily limited to the visible spectrum) and electromagnetic matter.

[0043] The optical devices in the group have different arrays or array groups that exhibit different characteristics that make these devices different. In addition, each optical device may include several arrays with different characteristics. That is, not only are the optical devices different from each other (because of their respective arrays), but in addition, the arrays of the same device may also be different. In that case, the optical characterization inspection performed with a given optical device may generate different light signals (due to the different arrays), which can be combined (when all arrays are illuminated simultaneously) or obtained one after another (when the arrays are illuminated one at a time in succession). All of these different signals accordingly affect or in some way form part of the results of the inspection. Such signals are used to capture or in some way affect the second data of the inspection performed by each optical device in the group.

[0044] For each device in the group, the first data and the second data are utilized as follows. First, refer to Figure 5 , based on the accessed first data identification S32 a given device 1 is obtained S33 a readout key associated S17 with the identified device. This assumes that the readout key has been designed to interpret S15 a specific characteristic of the given device 1. More generally, as will be explained in detail later, the readout keys associated with the optical devices 1, 1a-1c interpret the respective different characteristics of these optical devices.

[0045] Finally, the second data accessed for the given device 1 can be interpreted S35 based on the obtained readout key in order to clarify the results of the optical characterization inspection performed with this device 1. More generally, the same steps are performed for each device in the group in order to clarify the results of the optical characterization inspection performed with it (due to the corresponding readout key). These results can then be provided to the inspection device associated with the entity performing the inspection. For example, this device can be a diagnostic computer associated with an inspector, etc., or it can be an automated device that receives control instructions from another source.

[0046] Some of the concepts introduced above are now explained in detail. First, a physical fingerprint captures a unique physical characteristic of a device, which is typically an uncontrollable or non-deterministic characteristic of the device (e.g., a physically unclonable characteristic) caused by deviations or inaccuracies in the manufacturing process. In this context, such a physical fingerprint may be caused, for example, by manufacturing or composition inaccuracies. The physical fingerprint of a particular optical device 1 is utilized herein to identify and / or authenticate this particular device 1. This may require performing an initial characterization of the device to read out the associated physical fingerprint prior to performing the optical characterization check, e.g., Figure 5 As assumed in the flowchart.

[0047] In contrast to physical fingerprints, which typically capture non-deterministic properties of the device 1, the results of the optical characterization inspection are influenced by the deterministic properties of the corresponding array 21-26 of each device 1. Each optical device may, for example, include meta-surface structures 12 with different types of molecular receptors (see Figures 3 and 4) or other chemical substances. Some meta-surface structures may have receptors, while other meta-surface structures may not have receptors (see Figures 3 and 4). Figure 4 (as shown). In addition, some metasurface structure arrays may be coated with the same type of receptors (or may have no receptors at all), etc. Thus, the devices 1, 1a-1c may exhibit different functionalization patterns. The latter can be obtained, for example, by randomly varying the type of functionalization across the array of each optical device.

[0048] The purpose of the optical characterization examination performed is ultimately to detect a specific analyte. For example, the selective binding properties of the functionalized metasurface structure can be exploited to detect such an analyte. However, the different properties of the array of the optical device (e.g., the functionalized pattern) further act as an embedded security feature. In a variant of the functionalized pattern, other well-controlled properties of these arrays can be exploited to achieve the required security features, such as the geometry of the metasurface, resulting in optical properties that depend on the geometry, and therefore in an optical signal that depends on the geometry. The geometry of the metasurface here generally refers to the in-plane shape and size of the metasurface (e.g., elliptical, as in Figure 2 and 3) and / or the distance between two metasurface structures (per pair), although the role played by intra-pair distance is generally not as important as the in-plane shape and size of the metasurface. In another example, both receptor functionalization and geometric changes are utilized.

[0049] In all cases, because the array of various optical devices has different, pre-configured properties, these properties can act as a configuration secret. Because the devices are different and therefore have different configuration secrets, the results of the optical characterization inspection are "encrypted" (or obfuscated in some way) by virtue of the configuration secret. This is superior to solutions that would only utilize variations in the receptors and their geometries, as such variations could be detected or reverse engineered (e.g., using optical means, electron microscopy, chemical characterization, or even with a trained eye).

[0050] As previously mentioned, two types of data are accessed and utilized. The first data is used to identify S32 a specific device, for example in order to obtain an identifier for this device, and then identify S33 a readout key associated with this identifier, although the readout key can also play the role of an identifier. The readout key obtained is then used to clarify the results of the characterization inspection. That is, the readout key compensates for the specificity of each optical device so that the second data can be correctly interpreted. For example, such steps can be performed (at least in part) at a server 300 that communicates with a client device 200, 200a-200c (for example, a smartphone), which itself communicates data with the optical detector 100, 100a-100c (for example, a CMOS imager, CCD). As Figure 1 and Figure 2 As shown, the latter is used to read out the optical signal obtained by the optical characterization examination performed by the optical device 1, 1a-1c. Because the present method requires interaction with the client device 200, 200a-200c, some steps can be performed partially or jointly at the client device, for example, using a secure, dedicated application running thereon. In fact, some of these steps can be performed primarily at the client device 200, 200a-200c.

[0051] Tests performed with different optical devices 1, 1a-1c result in different readout signals and, therefore, different results. A given result is influenced by the unique characteristics of the arrays 21-26 of each optical device. This result can be significantly affected by electromagnetic or other physical interactions occurring between the set of two or more interacting elements, where the latter notably include the metasurface structure 12, the functionalized layer (if any), and the dielectric environment such as a solvent or other medium.

[0052] Each readout key interprets a corresponding unique characteristic of each device. Thus, obtaining the readout key allows the encrypted optical signal to be properly interpreted / decrypted. The readout key is generally unknown to the user performing the optical characterization.

[0053] This method allows for two levels of security. First, the physical fingerprint is difficult, if not impossible, to clone, allowing each device 1, 1a-1c to be unambiguously identified. Second, only the readout keys of correctly identified devices can be obtained. Users can also be authenticated in the process. Therefore, only legitimate devices (and possibly authenticated users) can cause the server and / or client devices to properly interpret the results obtained using the custom optical device.

[0054] All of this will now be described in detail with reference to specific embodiments of the invention. Firstly, two cases or categories of embodiments can be distinguished. In the first case, see Figure 5, the first data and the second data are read out as a result of different characterization (or detection) steps S24, S25. That is, before exposing S25 the device to one or more analytes and performing the second readout to obtain the second data, a preliminary optical readout is performed S22, S24. Typically, the preliminary optical readout is performed and processed efficiently (in less than 100 ms). In the second case, see Figure 6 , a single characterization step S25a is sufficient. In both cases, the required characterization steps can be performed at the point of care, in home care, in mobile care or according to any other suitable application setting.

[0055] exist Figure 6 In a second class of embodiments, a single readout is performed, thereby acquiring the first and second data in a single characterization check (of each device). The result of the characterization check is affected by both the respective array characteristics and the physical fingerprint of each device. In that case, the readout key may account S15 for the different array characteristics and physical fingerprint of each of the optical devices 1, 1a-1c. The first and second data may be accessed as follows. First, characterization data corresponding to a characterization check performed with a given optical device are received S31, and then in view of the identification S32 of said given device 1, the first and second data are determined S31a based on the received characterization data to obtain S33 the associated readout key. As Figure 6 As shown, the second data is finally decoded according to the obtained read key S35.

[0056] Figure 5 and Figure 6 It is assumed that steps S31, S31a, S33 and S34 are performed at the server. However, in a variant, these steps can be performed at the client device, and the server can only be used to confirm S32 the device ID and return the readout key in response to the query from the client device S33.

[0057] For example, when a physical fingerprint forms part of a metasurface array (or is embodied or formed in some way) or an optical device just detectably affects another part of the characterization examination, a single characterization step may be sufficient - in this respect, the first data and the second data may correspond to different characteristics of a single signal. In a variant, one of these characteristics may be derived from the other (for example, the first data may be a derivative of the second data). In all cases, the first data make it possible to identify S32 each device 1 to obtain S33 the associated readout key, and then interpret S35 the second data based on the obtained readout key.

[0058] Relying on a single characterization step (from which both types of data are obtained) can be advantageous in some applications because it simplifies the operations performed locally (e.g., at the point of care). However, such an embodiment may increase the complexity of data extraction. It must also be considered that the first type of embodiment ( Figure 5 Whether the benefits of this approach outweigh the disadvantages can be determined by the fact that the preliminary optical readout required in the apparatus (prior to analyte exposure) is generally simple to perform and not time intensive. A preliminary optical readout can be performed, for example, upon powering up the apparatus to ensure correct positioning of the optical apparatus when embodied in the disposable cartridge.

[0059] The physical fingerprint is preferably an unclonable property of the arrays 21-26 of each optical device 1. Such a property is sometimes referred to as a physical unclonable property. This unclonable property may have physical and / or chemical origins. This physical and / or chemical property may, for example, result from (e.g., uncontrolled or unintended) small dimensional variations in the metasurface structure 12, regardless of variations in geometry or morphology, chemical composition, and / or chemical functionalization. The unclonable property makes it more difficult (and indeed, practically impossible) for a malicious user to replicate the optical device.

[0060] In a variation of the intrinsic physical fingerprint of an array of optical devices, one can further rely on the unclonable property of another part of the optical device (i.e., different from the array), or even on a physical anchor that is intentionally provided and attached to or integrated in these optical devices. The physical anchor can, for example, be unalterably attached to (entangled with) the optical device, for example using a strong adhesive, or in a manner that irrevocably alters the optical device or its primary functionality when removed, destroyed, or otherwise altered. The anchor can also be integrated in an unalterable manner into the body of the optical device.

[0061] As previously discussed with respect to inherent physical fingerprints, the physical anchor may, for example, include embedded security features (e.g., microprinting, security inks, fluorescent dyes, or holograms) and / or unclonable functionality. Such a physical anchor is preferably attached to the optical device itself, rather than its packaging, because the trust anchor is established for the object that hosts the physical anchor. That is, the best protection is achieved for the actual object whose unique physical characteristics are exploited.

[0062] Physical anchors generally make it easier to achieve unique physical properties of optical devices, and to do so in a more systematic and controllable manner. Nevertheless, inherent physical fingerprints will generally provide a greater degree of entropy, which makes them more difficult to clone. In contrast, intentionally provided physical anchors are, in principle, easier to attack precisely because they are more controllable and systematic. Thus, some effort must be put into generating uniqueness of explicit physical anchors. In variants that rely on intentionally added anchors, the unclonable property can be characterized independently of the array, such as Figure 5 As assumed in .

[0063] Nonetheless, in each of the two cases described above (whether based on intrinsic fingerprints or on added physical anchors), the physical property exploited preferably reflects an uncontrollable (or not fully controllable) manufacturing feature, i.e., a non-deterministic property that is subject to certain non-deterministic variations but is still detectable, making the property unclonable.

[0064] In other variations, instead of exploiting the unclonable property of the array or intentionally added physical anchors, one may rely on embedded security features (e.g., microprinting, security ink, or holograms.) Such features are typically deterministic features, but are still difficult to clone.

[0065] Now refer to Figures 2 to 4 The optical device 1, 1a-1c preferably includes two or more arrays 21-26 of meta-surface structures 12, which impart different properties to the optical device 1, 1a-1c. The latter are correspondingly different from each other. The different properties can be caused, for example, by controlled (i.e., desired) size and / or composition variations in the meta-surface structures and / or their coatings, as discussed in detail below.

[0066] Advantageously, due to the preferred manufacturing method disclosed herein (see Section 2.2), metasurface structures can be manufactured with an accuracy of 1 nm. The properties obtained by the array accordingly can be said to be deterministic, as they result in different but predictable properties. Therefore, when performing an optical characterization check, they result in different characterization results. Therefore, an appropriate readout key can be deterministically assigned to the optical device, such a key comprising a code by which the results of the characterization check can be correctly interpreted (i.e., descrambled).

[0067] However, as mentioned above, the array may also be affected by non-deterministic properties. In this case, the array has a partially (actually substantially) deterministic and partially non-deterministic nature. However, the readout key can be designed to account for both types of properties.

[0068] In some embodiments, at least one of the metasurface structures 12 of each array of optical devices 21-26 is coated S11 with a substance for selectively binding the analyte, see Figure 4. These substances form the corresponding functionalized patterns of the arrays 21-26 of the optical devices 1, 1a-1c. In this case, for each optical device 1, the result of the second data capture is affected by both the meta-surface structure 12 of the corresponding array 21-26 and the corresponding functionalized pattern in the functionalized pattern. Consistently, these readout keys must interpret S15 the corresponding functionalized pattern. That is, the optical devices 1, 1a-1c have different functionalized patterns, resulting in different deterministic properties that serve as configuration secrets. In a variant, or in addition to the pattern, other well-controllable properties of the array 21-26 can be utilized, such as the geometry of the meta-surface structure 12 as described above.

[0069] These substances can be, for example, chemical receptors or other substances (e.g., particles) for binding analytes. However, the use of particles may not be desirable because particles may add additional variations that cannot be easily controlled, and the additional variations may compete with the non-deterministic aspects provided in other ways. Therefore, these substances preferably include molecular receptors 52-55 that are adapted to selectively bind to the analyte of interest. That is, for each optical device of the group, the metasurface structure 12 of at least one of the corresponding arrays 21-26 can be coated S11 with molecular receptors 52-55. In this way, the arrays of optical devices 1, 1a-1c can be functionalized according to the functionalized pattern formed by the molecular receptors 52-55. It is possible for the arrays 21-26 of each optical device to be coated S11 with different types of molecular receptors 52-55 so as to be able to selectively bind to different types of analytes.

[0070] like Figure 4 As shown, the molecular receptors are advantageously formed as molecular compounds 52-55 immobilized on the surface of the meta-surface structure 12. Each of the molecular compounds 52-55 comprises several parts, including a first part 50a that is anchored to the top surface of the meta-surface structure 12, and a second part 62-65 that is a molecular receptor with high binding affinity for certain analytes. The receptors 62-65 are chemically linked 50d to the first anchoring part 50a via a backbone 50b.

[0071] like Figure 4 As further seen in FIG, these moieties may further include a third moiety 50c. The latter may be, for example, a protecting moiety for acetylene, for example comprising a redox-active naphthoquinone chromophore. The protecting moiety 50c is bonded to the acetylene unit of the backbone 50b via an electrochemically cleavable bond. Thus, it is necessary, for example, Figure 4 As shown, the acetylene unit of the anchored molecular compound is deprotected S11 by electrochemically cleaving the protecting moiety before binding the molecular receptor to the released acetylene unit. The molecular compound thus obtained can then be exposed S25 to an analyte for optical characterization.

[0072] The deprotection mechanism can be based on, for example, electrochemical reduction of the protecting moiety. Single-electron reduction mechanisms, oxidation mechanisms, or promoted two-electron mechanisms are preferred because such mechanisms are more efficient and require less electrochemical energy. Since the initially protected acetylene units are fixed to the surface via the backbone and the anchoring moiety, the deprotection mechanism results in an acetylene-functionalized surface. Thus, it provides a chemically flexible attachment that makes it possible to subsequently bind a wide variety of functional receptors to these cleaved compounds, i.e., by chemically binding to the released acetyl groups.

[0073] For example, as described above, the meta-surface element 12 can be formed as a semiconductor structure 12 coated with a molecular receptor, such as silicon, and the molecular receptor is formed as a molecular compound fixed on the top surface of the meta-surface structure 12. In a variant, people can functionalize the structure 12 with antibodies, viruses, or other types of particles for sensing applications, which can all be directly (in the form of physical adsorption) or fixed via chemical compounds to achieve a functionalized layer of physical adsorption. Moreover, the binding portion 50d can be composed of antibodies, RNA, DNA, etc., and is intended to selectively capture various types of analytes via chemical binding interactions. As described above, not all meta-surface structures 12 of each optical device need to be functionalized. In addition to chemical functionalization, the meta-surface structure can also have, for example, meta-surface intrinsic properties for light manipulation purposes.

[0074] The preferred optical characterization examination will now be described in detail. Figure 1 As shown, the optical characterization inspection S25, S25a performed involves electromagnetic interaction, whereby the array of devices 1, 1a-1c is illuminated (i.e., irradiated) S25 with electromagnetic radiation, which in turn induces a spectral response of the optical devices. Accordingly, the results of the optical characterization inspection S25, S25a may include optical data representing the spectral response of each optical device. Second data (and possibly first data) are then extracted from the optical data.

[0075] In some embodiments, each array of each optical device 1 is illuminated with electromagnetic radiation (e.g., using a spectrally narrow light source) at a frequency that matches the resonant frequency of the array's metasurface structures 12 in the absence of an analyte. The narrow light source is centered at a specific frequency that matches the resonant frequency of an empty receptor metasurface layer. This process is intended to exploit the inherent, built-in spectral properties of dielectric metasurfaces, where, for example, very narrow absorption resonances are used. This allows the spectrometer (and the optical signal to be read out) to be replaced when using a single narrow light pulse or a combination of multiple spectrally different narrow light pulses with a CMOS imager.

[0076] The best transfer settings are as follows Figure 1As assumed in [ 1 ] . In this case, the spectral response of each optical device 1 is the response to electromagnetic radiation transmitted through the optical device 1 . In a variant, a reflective setup can be used. In both cases, the spectral response of the device 1 reflects the absorption changes caused by the effective change in the dielectric environment of the meta-surface structures 12 of one or more of the arrays 21-26 of the optical device 1 . It may be desirable to observe a shift in the absorption resonance upon selective capture of an analyte on a specific meta-surface structure 12 of one or more of the arrays 21-26 of the optical device 1 , either during absorption or transmission, whereby the analyte chemically binds to the meta-surface structure 12 due to specific analyte-binding molecule receptors. Upon analyte binding, the optical resonance of the meta-surface structure changes. This allows for label-free sensing measurements without the use of radioisotopes, fluorescent dyes, or the like, because the presence of the analyte directly affects the optical properties of the meta-surface 12. This approach offers higher sensitivity and higher spatial resolution than, for example, methods based on localized surface plasmon resonance.

[0077] In some embodiments, the array is sequentially illuminated (one array at a time). Ultimately, the result of the optical characterization inspection may include several results, gathering the results obtained for each array. In a variant, all arrays can be read simultaneously, for example, using a two-dimensional (2D) CCD detector (with spatial resolution), which further allows energy to be distinguished. In other variants, each array is subjected to multiple optical inspections, for example to capture different analyte-receptor binding kinetics and generate a transient signal when the analyte is bound to the receptor. This allows for data analysis that interprets binding kinetics as distinguishing features.

[0078] It is possible to envision having several types of optical metasurface structures 12 on the same chip, such as dielectric metasurfaces, surface plasmon resonance (SPR) metasurfaces using gratings or nanohole arrays, such as localized SPR metasurfaces (e.g., using nanohole arrays, nanoantennas, or nanostructures arranged on a substrate). Thus, it is possible to envision performing several types of optical characterization tests (in terms of emission, or if the substrate is transparent, in terms of transmission) on the same chip, such as non-resonant or resonant light scattering tests (again, in terms of emission, or if the substrate is transparent, in terms of transmission), light absorption tests, light emission tests, etc., with dielectric or semiconductor (e.g., silicon) metasurface structures arranged on a substrate.

[0079] Next, refer to Figure 1 and Figure 2The preferred configuration is discussed. The method is preferably performed at least partially at a server 300. The latter can, for example, communicate data with a set of client devices 200, 200a-200c (e.g., mobile devices). The client devices typically communicate with an optical detection device 100, 100a-100c (e.g., a CCD) for performing optical measurements, see Figure 1 and Figure 2 .

[0080] The server receives data S31 from each client device (usually asynchronously, i.e. at different times), see Figure 2 、 Figure 5 and Figure 6 . Each client device 200, 200a-200c is paired with a corresponding optical device 1, 1a-1c. Thereby, the first data and the second data can be accessed by the server 300 based on the data received in step S31. This enables, in particular, the server to identify (S32: Yes) the relevant optical device 1 based on the accessed first data and then to interpret (S35) the second data based on a readout key obtained based on the first data. The server can then send S36 a report to the client device. For example, the server can send S36 a message including information about the clarified result. If the identification fails (S32: No), the server can typically invite S34 the user to redo the characterization check, record the attempted identification, prompt the user to use another device and / or block further attempts if necessary, etc.

[0081] Upstream of the user operation S20 and the server operation S30, some preparatory work needs to be performed by the manufacturer, for example, before or while commissioning the optical device, as now referred to Figure 5 and 6 As described. In some embodiments, the method comprises a series of preliminary steps, which are also performed for each optical device of the group of optical devices 1, 1a-1c. Such preliminary steps include manufacturing S11 each optical device for a respective array 21-26 exhibiting different characteristics. Then, a readout key is designed and associated S17 to each manufactured device. The readout key explains the specific characteristics of each optical device (this includes the deterministic characteristics of the array and may also include a physical fingerprint). The readout key can eventually be stored together with a unique identifier for each optical device, but in a variant, the readout key may serve as an identifier for the device.

[0082] After its manufacture S11, each optical device is characterized, for example, by the manufacturer, in order to read out S14 its respective physical fingerprint. A corresponding digital fingerprint is obtained accordingly. The digital fingerprint is associated S17 with an identifier of the optical device and stored, allowing the optical device to be unambiguously identified later. If this fingerprint must influence the key, the key must be designed with this in mind.

[0083] All data related to the optical device can then be transferred to a dedicated database, such as a dedicated database accessible from the server 300. The database may be a distributed system, preferably configured as a shared ledger. The shared ledger can in particular be configured as a blockchain, and more preferably, as a business blockchain such as the so-called Hyperledger Fabric, or a similar blockchain.

[0084] As described above, readout keys account for the individual characteristics of optical devices and can include the effects of physical fingerprints. Using a readout key allows for the correct interpretation of results obtained with the respective devices. For example, consider two optical devices D1 and D2 with different arrays, resulting in affine shifts s1 and s2 of the readout data. For example, the corresponding shift functions could be s1(x) = 2x + 3 and s2(x) = 3x + 5. In this case, the corresponding readout key can simply be the corresponding inverse function: x1 = (s1 – 3) / 2 and x2 = (s2 – 5) / 3. Therefore, without the corresponding key, the readout data {y1} and {y2} obtained using devices D1 and D2, respectively, cannot be correctly interpreted. The above examples are intentionally simplified; actual readout keys are typically more complex. Generally speaking, such keys can be viewed as some inverse transformation of the changes caused by the arrays. However, given that no inverse transformation is generally available for analytical analysis of such changes, the readout key may have to be tabulated or otherwise defined as a numerical function or algorithmic procedure. For example, they may be obtained as cognitive models trained using machine learning or learned parameters of such models.

[0085] Now refer to Figure 7A —7C discussion example. Figure 7A describes the estimated theoretical bin for a given optical device. That is, Figure 7A It is assumed that certain optical properties can be achieved by rationally designing a metasurface array of an optical device comprising multiple (three in this example) metasurface arrays. The target property can be, for example, optical wavelength resonance. The design takes into account the manufacturing process and its tolerances so that the optical response of the manufactured metasurface structure will be located in certain spectral bins (i.e., wavelength or energy intervals), where each bin is spectrally well separated from the adjacent bins (in wavelength or energy). The design of the array further enables the anticipation of prohibited (unused) spectral ranges. The size of the bin is to account for inaccuracies in the manufacture of the metasurface (receptor functionalization, if any), as well as offsets caused by analyte binding during optical sensing inspections. That is, the bin width can be estimated to ensure that the actual characterization inspection does not offset the target optical property outside the corresponding bin. Therefore, the bin structure can be regarded as a classification structure. The bin feature can be used as an identifier for a given device.

[0086] Then make the optical device ( Figure 7B) to have deterministic optical properties as previously planned during the design phase. Uncontrollable manufacturing inaccuracies cause random deviations from the expected theoretical optical properties as predicted by the design. The same is true when the metasurface is functionalized with receptors, because these receptors are partially uncontrollable at the microscopic level. For example, local receptor surface density, receptor-to-surface orientation, stacking characteristics, folding, etc. can affect the actual optical properties of the metasurface. All sources of inaccuracy combine to result in deviations from the theoretical design properties R as initially estimated. i ,i=optical offset of A, B and C( Figure 7A ). After manufacturing, the optical properties are read out for each individual optical device (taking into account functionalization, if any). This is done before commissioning the device, without exposing it to the analyte. The actual obtained check value R i,实际 With the value R i For example, the obtained R i,实际 Linked to the corresponding radio frequency identification (RFID) tag and stored in the database.

[0087] refer to Figure 7C , before performing a sensing test with an analyte using the optical device, the user now reads out the optical device (ie, this corresponds to Figure 5 22, S24 in ). This results in optical characteristics that can be compared with the stored characteristics. Considering that the device may have undergone some slight changes (e.g., temperature may affect the molecular functionalization on the surface), the values ​​obtained by the user may change slightly compared to the stored characteristics, so it is advantageous to use bins (ranges) for classification purposes rather than using specific (precise) spectral data values. In addition, the values ​​obtained by the user can be identified as belonging to certain bins, which in turn can be used to identify the device and the corresponding readout key (e.g., bin position and signal shift caused by the array).

[0088] The above example assumes that two measurements are taken by the user: a first measurement to identify the optical device before exposing the device to the analyte, and a second measurement to perform the test in the presence of the analyte, as previously described with reference to Figure 5 As discussed.

[0089] In variants, such as Figure 6 The single characterization step assumed in

[15] might be sufficient if the same type of characterization check can be performed a first time while commissioning the optical device and a second time by the user. In this case, the results of such a characterization check may be influenced by both the physical fingerprint and the deterministic nature of the array. That is, the two types of information are entangled in a single measurement.

[0090] For example, the device can be designed for each array to result in a certain theoretical optical property, such as a given optical resonance in the presence of a given analyte. By design, it is possible to ensure that the ideal value of this property will fall within a certain interval (bin), as explained above. Now, when performing characterization checks, some deviations from the theoretical optical property will usually be observed, where such deviations are the result of uncontrollable non-deterministic properties caused, for example, by the manufacturing of the optical device. Now, the set of deviations obtained for all arrays will usually be unique, which can be used to identify the device, as previously referenced Figure 6 As explained.

[0091] The optical device can be identified using a corresponding identification pattern obtained (e.g., at a server): before or simultaneously with commissioning the device, this pattern is associated with a unique ID (identifier), and a {UID, identification pattern} pair is stored. Later, when the user performs a characterization check using the device, the results of this characterization again include deviations from the ideal optical properties; these deviations are converted into an identification pattern, which is transmitted to the server. The corresponding readout key is then identified and used to interpret the resonance value measured by the user. In that case, only one characterization measurement needs to be performed by the user, the result of which entangles the two types of data (i.e., the first data corresponding to the physical fingerprint and the second data corresponding to the deterministic properties).

[0092] The example in Figure 7 assumes only three arrays, but a real chip may typically include n x n arrays, where in practice n is typically greater than or equal to 6. The output optical signals can be read simultaneously on, for example, a CCD detector with high energy resolution or a CMOS reader with lower energy selectivity but higher spatial resolution.

[0093] Return Reference Figure 3A and Figure 3B Each array of each optical device 1, 1a-1c preferably forms a pattern of repeating units, wherein each unit is composed of two elementary surface structures 12. For the purpose of description, Figure 2 The example shown in FIG3 assumes very small arrays of 3×2 cells each (3×4 metasurface structures).

[0094] In some embodiments, the metasurface structure 12 is formed as a semiconductor layer structure arranged on top of a substrate. The semiconductor structures may, for example, each have an average lateral dimension between 1 nm and 500 nm. Figure 1The lateral dimension is measured in the plane (x, z) in Figure 3. In some embodiments, the lateral dimension is greater than 50 nm and the standard deviation of the lateral dimension is less than 5 nm. The semiconductor structures can advantageously each have a vertical dimension that averages between 10 nm and 500 nm. The vertical dimension is measured perpendicular to the main surface of the substrate. In some embodiments, the vertical dimension is greater than 100 nm and the standard deviation of the vertical dimension is less than 5 nm. The manufacturing methods discussed in the relevant summary allow for near-nanometer accuracy.

[0095] Another aspect relates to a computer program product for interpreting an optical characterization inspection performed using a set of optical devices 1, 1a-1c as described above. The computer program product includes a computer-readable storage medium having program instructions embodied therein, which are executable by a processing device (i.e., a processor) to cause the latter to perform steps such as those described above with respect to the present method. For example, these steps can be at least partially performed at a server 300 (and the execution of corresponding instructions), and can also be performed jointly at the server and connected client devices 200, 200a-200c. Further details regarding this computer program product are provided below in Section 2.3. Section 2.4 further describes computerized devices generally related to performing the present method.

[0096] The above embodiments have been briefly described with reference to the accompanying drawings and may have a number of variations. Several combinations of the above features are contemplated. Examples are given in the next section.

[0097] Section 2 Specific Implementation - Technical Implementation Details 2.1 Specific Examples

[0099] This section discloses a novel cryptographic anchor tailored for multi-analyte sensor systems used in diagnostics to ensure reliable, secure, and fraud-proof (anti-counterfeiting) operation. The proposed cryptographic anchor concept is particularly applicable to dielectric metasurface-based IoT diagnostics, which can benefit from secure readout protocols implemented via the cloud.

[0100] As described in Section 1, this approach combines an uncontrollable, manufacturing-dependent physical fingerprint and a controllable, manufacturing-dependent embedded security feature with specific receptor surface functionalization that acts as a configuration secret. For each individual analytical / diagnostic operation performed on an analytical device (e.g., a laboratory spectrometer, a CMOS imager, or a mobile phone), such features allow for secure, cryptographic readout of diagnostic results via the cloud, effectively preventing product counterfeiting and reuse.

[0101] The underlying optical device is designed as a sensor chip, and the arrangement of the sensor chip is an arrangement that includes the following:

[0102] - two (or more) arrays of plasmonic or dielectric metasurfaces 12 with defined geometries (bowbands, rods, ellipses, disks, etc., not strictly identical geometries), material compositions (e.g., metals, highly doped semiconductors, high refractive index dielectrics, 2D layered materials, not strictly identical) and / or morphologies (e.g., crystalline, polycrystalline, amorphous, etc.), where each component may be divided into multiple material segments; and

[0103] - A receptor-based surface coating with molecular compounds ensuring functionalization, immobilized on each individual metasurface 12 , which allows selective binding of the analyte (eg upon formation of a chemical bond therewith).

[0104] In some embodiments, the sensor chip further comprises: channels that enable analytes to be transported to the element surface array in a gas phase or liquid phase (or a phase mixture) with certainty; and / or other gas or liquid processing components, such as filters, fluid mixing elements, reagent addition components, separation components, upper concentration components, etc. In addition, such a chip may further comprise or be connected to a pump (passive or active), a pipe, a pipe port, a vent, a loading pad, an electrical contact pad, an electrical connector (e.g., printed), etc.

[0105] The operation of the chip relies on electromagnetic exchange or coupling mechanisms between metasurfaces, between metasurfaces and their respective receptor coatings, and / or between metasurfaces / coatings and their dielectric environments, which produce a collective optical effect. In some embodiments, it also involves electromagnetic or dielectric field enhancement mechanisms through resonant coupling effects (e.g., collective Mie resonators).

[0106] This sensing chip is used in a sensing device or system as described below. The sensor chip is exposed to an analyte (e.g., from a solution or gas phase) so that the analyte can interact with the corresponding receptor (functionalized) and thus potentially bind to a specific position in an analyte-selective manner. The binding of the analyte changes the dielectric environment of the element surface 12, which results in a shift in the absorption resonance. This shift can be read out with a very simple optical device, for example, a narrow light source centered on the resonance of an empty receptor element surface layer. Since most of the light is absorbed, the intensity measured on the detector is low. When the analyte is bound, as the dielectric environment changes, the absorption resonance of the element surface shifts (usually to a higher wavelength), and the previously absorbed light now passes through the element surface almost 100%, causing a much higher intensity on the detector.

[0107] For example, the chip may include a metasurface 12 functionalized with molecular receptors, a microchannel-based gas or liquid handling (e.g., capillary drive) system, and an RFID chip. That is, in order to identify a sensing chip with a UID, an RFID chip may be attached to the sensing chip, wherein the RFID chip may be programmed or read out.

[0108] Due to the fabrication methods disclosed in the next subsection, the metasurface 12 can be manufactured with unprecedented precision, which leads to unprecedented, intrinsic optical properties of the metasurface, which can be used for receptor-free and / or receptor-based sensing.

[0109] This approach allows for the inclusion of physical fingerprints and embedded security features (particularly for meta-surfaces).

[0110] As mentioned earlier, physical fingerprints refer to material characteristics that are little or uncontrollable, including manufacturing and / or compositional variations. Variations can be observed significantly in: geometric dimensions (length, width, thickness); material composition (homogeneous composition, heterogeneous composition); material morphology; material crystallinity; and material functionalization.

[0111] While the aforementioned parameters can also be used as controllable deterministic features for use as embedded security features of metasurfaces (see below), even minimal changes in nanofabrication or material composition can cause detectable changes in the optical properties of the original metasurface. Such properties can then be characterized for each individual device and thus used as a unique security feature, i.e., a physical fingerprint that cannot be easily copied, discovered, or reverse engineered.

[0112] The following non-exhaustive list provides examples of different types of inaccuracies that arise in the fabrication or material composition of dielectric metasurface devices and that can be exploited in the present context: material deposition inaccuracies, e.g., sputtering, MBE, or ALD growth; chemical resist inaccuracies; surface contamination; mask contamination or defects; imprint contamination or defects; dry etch inaccuracies; wet etch inaccuracies; anisotropic or isotropic effects; nucleation; crystal defects with different etch rates; loading effects in ICP DRIE; and / or tapering.

[0113] Most of these effects are interdependent. For example, resist defects can affect the masking layer and subsequent transfer steps using the mask. These undesirable and uncontrollable phenomena typically occur in true 1-nanometer manufacturing, as controlling all of these processes in conventional manufacturing or the component processes at this scale is impossible. However, metasurfaces are highly sensitive to such inaccuracies, as their optical properties are directly affected and altered accordingly.

[0114] Fortunately, such physical fingerprints can be characterized after manufacturing, and their detection fingerprints can be characterized and stored relative to each specific sensing chip, which can later be exploited to identify such devices, as explained in Section 1.

[0115] In addition to the uncontrollable physical fingerprint, the underlying physical parameters can also be controlled to a large extent, resulting in embedded security features that can be used to customize the properties of the original metasurface and its functionalization. That is, embedded security features can be implemented for the metasurface.

[0116] The following parameters can be used as design parameters for the metasurface: geometric shape (circular, triangular, elliptical, rod, etc.), geometric dimensions (length, width, thickness); material composition (homogeneous composition, heterogeneous composition); material stacking, material morphology, and material crystallization. In principle, such characteristics can be varied for each individual chip to be manufactured. However, economically, the electron beam writing master is most often changed only during each VLSI-compatible nanoimprint master manufacturing step, depending on the level of safety requirements to be achieved. For example, various master devices exist and are used in a variable manner in the pick-and-place process.

[0117] The above parameters can be varied at the wafer, array level, or at the sub-array level (e.g., at the level of metasurface elements). While variations in geometry or size as design parameters do not necessarily result in additional costs, changes in material composition, morphology, crystallinity, etc. can be more complex and therefore more expensive.

[0118] Each multi-receptor sensing chip can, for example, comprise an array of metasurfaces with different physical fingerprints and, optionally, each with a different embedded security feature, forming, for example, a 6×6 matrix. Thus, specific localized functionalizations can also serve as embedded security features. These features can be modified during the deposition of receptor compounds onto the metasurfaces using deposition processes such as those based on droplet coating, inkjet or nanoelectrospray coating, as well as micro- and nanofluidic deposition methods. While receptor compounds for diagnostic tasks must be present on at least one array element for capturing the corresponding analyte, additional embedded security features beyond simple variable assembly can be considered.

[0119] Additional embedded security features may include, for example: receptor-free array elements; receptor-masking compounds on array elements; non-selective receptor compounds; and redundant receptor types on other array elements, see Figure 2 —3.

[0120] Functionalization can be varied, for example, using a random generator, during compound assembly at the sensor chip level. Given a large number of array elements (e.g., 6×6), the various types of molecular receptors available, and the inherent entropy of the physical fingerprints used herein, enormous combinatorial power can be used to create hardware-based cryptographic anchors. A given type of receptor may be required to sense a given target analyte. However, for security reasons, such receptors can be hidden, masked by other types of receptors.

[0121] Another measure that can be used to protect the readout process and prevent misuse of the sensing device (for example, reuse through resale) is to physically separate the readout key from the sensing device. This security feature protocol can be used as a configuration secret; it can be implemented into the software required to operate the light detectors 100, 100a-100c. The preferred solution is as follows. Via the cloud, the readout key is only granted when certain conditions are met, which can be tracked in a database, for example, the sensing chip can be properly identified, it is confirmed that the chip has not been used before, etc. This principle enables full control over the use of the IoT device. However, depending on the application, the diagnostic results can only be accessed by authorized users, patients, registered physicians, etc., as they are considered sensitive data.

[0122] Given the high-resolution and high-precision sensing performance achieved by this method, a wide range of applications can be envisioned. Typical sensing applications notably include: sensing of different compounds; multiplexed sensing; medical diagnostics, drug compliance, metabolic studies, environmental monitoring; analysis of exhaled breath (volatile organic compounds, metabolites, etc.); nanochemistry with educts and product analysis; photocatalytic engineering of sensing elements; and metabolomics.

[0123] The optical devices (sensing chips) of the present invention can be used as "mobile" devices, which are particularly suitable for diagnosis by general practitioners at the point of care, mobile emergency diagnosis, in home care or mobile screening tests, or in situations where the patient's own medical history is checked or the patient himself has to check very frequently (for example to adjust the dosage of a drug according to metabolic activity), although they can also be used in diagnostic medical laboratories.

[0124] Medical diagnostic applications notably include: myocardial infarction detection; stroke detection; HIV detection; sexually transmitted disease detection; Alzheimer's plaque detection; medication compliance or adherence; drug-triggered metabolic reactions; and adverse drug reactions.

[0125] 2.2 Preferred manufacturing method

[0126] The optical device is preferably obtained according to a manufacturing method, wherein a layer structure having a semiconductor layer is processed to form a metasurface structure. The manufacturing method relies on a layer structure comprising a substrate, a layer stack and a resist structure. The latter each comprises a resist material comprising a semiconductor element. The layer stack is arranged on top of the substrate. The resist structure is patterned on the layer stack and can be realized by electron beam lithography (EBL) and / or nanoimprint lithography (NIL) methods. The layer stack comprises: a semiconductor layer (arranged on top of the substrate); a protective layer (arranged on top of the semiconductor layer); a transfer layer (arranged on top of the protective layer). The protective layer preferably comprises Al x O y, while the transfer layer may, for example, comprise SiO 2 . The layer structure may, for example, be obtained by forming a layer stack on top of the substrate, wherein the protective layer is deposited using a process such as atomic layer deposition, chemical vapor deposition, sputtering or the like.

[0127] The exposed portions of the transferred layer are removed by selectively etching the transferred layer. The exposed portions are the unmasked portions, i.e., the portions not masked by the resist structure. After removing the exposed portions, a remnant of the transferred layer remains between the protective layer and the resist structure. Note that a selective etching process is an etching process that is selective with respect to the material to be removed (in this case, the transferred layer), meaning that the target material is removed more efficiently than other exposed materials. The selectivity of the etching process is typically between 100 and 10,000.

[0128] Next, the resist structure is completely removed by another selective etching process. This results in the exposure of the transferred layer structure formed by the remaining portion of the transferred layer. The transferred layer structure is then transferred into the protective layer by selectively etching the protective layer using a further selective etching process. In this way, a combination of residual layer portions is obtained, each of which contains a residual portion of the protective layer and a residual portion of the transferred layer.

[0129] Afterwards, the semiconductor layer is selectively etched to obtain a residual semiconductor structure. For example, the semiconductor layer is selectively etched using an inductively coupled plasma process, preferably based on BCl3. At this point, the residual semiconductor structure is still partially masked by the combined portion of the previously obtained residual layer portions. Therefore, by selectively etching the combined portion, the combined portion is ultimately completely removed. This results in the exposure of the semiconductor structure. In this way, a metasurface structure is obtained that is arranged according to the pattern initially formed by the resist structure on the initial layer stack. For example, the above-described manufacturing method can be performed to obtain a flat optical element whose metasurface is formed by the semiconductor structure.

[0130] The above-mentioned manufacturing method relies on an indirect transfer process, which results in unprecedentedly precise and clean metasurface structures. This is made possible by the continuous, selective etching steps in a multi-step, multi-layer process, which in particular allows the removal of the resist structure while keeping the semiconductor layer protected, even if the resist material includes semiconductor components. Moreover, the above method is compatible with nanoimprint lithography (NIL) and electron beam lithography (EBL) methods. Therefore, the resist structure can be initially obtained using either the NIL process or the EBL process. Therefore, when using NIL, the mold used to obtain the initial resist structure can be used multiple times, making the present method compatible with large-scale manufacturing and operating at a much lower cost than a separate sequential EBL patterning.

[0131] 2.3 Computer Program Products

[0132] The present invention may be a system, method, and / or computer program product at any possible level of technical detail integration. The computer program product may include a computer-readable storage medium having computer-readable program instructions thereon for causing a processor to execute various aspects of the present invention.

[0133] Computer readable storage medium can be a tangible device that can retain and store the instruction used by the instruction execution device.Computer readable storage medium can be, for example but not limited to, electronic storage device, magnetic storage device, optical storage device, electromagnetic storage device, semiconductor storage device or any suitable combination of the above.The non-exhaustive list of the more specific example of computer readable storage medium includes the following: portable computer disk, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disk read-only memory (CD-ROM), digital versatile disk (DVD), memory stick, floppy disk, mechanical encoding device such as punch card or the protruding structure in the groove with the instruction recorded thereon and any suitable combination of the above.Computer readable storage medium as used herein should not be interpreted as transient signal itself, such as radio wave or other free propagating electromagnetic wave, electromagnetic wave (for example, light pulse through fiber optic cable) propagated by waveguide or other transmission medium or the electric signal emitted by wire.

[0134] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network can include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium within the corresponding computing / processing device.

[0135] The computer-readable program instructions for performing the operation of the present invention can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data or source code or object code written in any combination of one or more programming languages, which include object-oriented programming languages ​​(such as Java, Smalltalk, C++ etc.) and conventional process programming languages ​​(such as " C " programming languages ​​or similar programming languages). The computer-readable program instructions can be performed completely on the user's computer, partly on the user's computer, performed as an independent software package, partly on the user's computer, partly on a remote computer, or fully on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer by any type of network (including local area network (LAN) or wide area network (WAN)), or can be connected to an external computer (such as, using an internet service provider through the internet). In certain embodiments, the electronic circuit comprising for example programmable logic circuit, field programmable gate array (FPGA) or programmable logic array (PLA) can be personalized to perform the computer-readable program instructions by utilizing the state information of the computer-readable program instructions to perform the electronic circuit, so as to perform various aspects of the present invention.

[0136] The present invention is described below with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. Various aspects of the present invention are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0137] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions / actions specified in the flowchart and / or block diagram or multiple blocks. These computer-readable program instructions can also be stored in a computer-readable storage medium, where these instructions cause the computer, programmable data processing device, and / or other device to operate in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes an article of manufacture containing instructions that implement aspects of the functions / actions specified in the blocks of the flowchart and / or block diagram.

[0138] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, so that a series of operational steps are performed on the computer, other programmable apparatus, or other device to produce computer-implemented processing, so that the instructions executed on the computer, other programmable apparatus, or other device implement the functions / actions specified in the flowchart and / or block diagram or multiple boxes.

[0139] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions and operations of possible implementations of the systems, methods and computer program products according to various embodiments of the present invention. To this end, each box in the flowchart or block diagram may represent a module, segment or portion of an instruction, which includes one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions annotated in the box may not occur in the order annotated in the figure. For example, depending on the functions involved, two boxes shown in succession may actually be executed substantially simultaneously, or the boxes may sometimes be executed in the opposite order. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

[0140] 2.4 Examples of suitable computerised units

[0141] Computerized devices can be suitably designed to realize embodiments of the present invention as described herein.For example, one or more computerized units can be related, each including a general-purpose computer.In an exemplary embodiment, in terms of hardware architecture, the unit can include a processor, a memory coupled to a memory controller, and one or more input and / or output (I / O) devices (or peripheral devices) coupled via a local input / output controller. The input / output controller can be, but is not limited to, one or more buses or other wired or wireless connections as known in the art. The input / output controller can have additional elements omitted for simplicity, such as a controller, a buffer (cache), a driver, a repeater, and a receiver, to realize communication. Further, the local interface can include address, control, and / or data connections to realize appropriate communication between the above-mentioned components.

[0142] A processor is a hardware device for executing software, particularly software stored in memory. A processor can be any custom or commercially available processor, a central processing unit (CPU), a secondary processor among several processors associated with a computer, a semiconductor-based microprocessor (in the form of a microchip or chipset), or generally any device for executing software instructions.

[0143] The memory may include any one or a combination of volatile memory elements (e.g., random access memory) and non-volatile memory elements. In addition, the memory may include electronic, magnetic, optical, and / or other types of storage media. Note that the memory may have a distributed architecture in which different components are located remotely from each other but are accessible by the processor.

[0144] The software in the memory may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing logical functions. Specifically, the software in the memory may include the methods described herein according to exemplary embodiments and a suitable operating system (OS). The OS essentially controls the execution of other computer programs and provides scheduling, input-output control, file and data management, memory management, and communication control and related services.

[0145] The method described herein can be in the form of a source program, an executable program (object code), a script, or any other entity including a set of instructions to be executed. When in source program form, it is necessary to translate a program via a compiler, an assembler, an interpreter, etc. (which may or may not be included in a memory, as known per se) to suitably operate in conjunction with an OS. In addition, the method can be written as an object-oriented programming language with data and method classes, or a procedural programming language with routines, subroutines, and / or functions.

[0146] Possibly, a conventional keyboard and mouse may be coupled to the input / output controller.Other I / O devices may include other hardware devices.

[0147] In addition, I / O devices may include devices that transmit both input and output. The computerized system may also include a display controller coupled to a display. In an exemplary embodiment, the system may further include a network interface or transceiver for coupling to a network. The network sends and receives data between the computerized unit and the external system. The network may be implemented wirelessly, for example using wireless protocols and technologies such as WiFi, WiMax, etc. The network may be a fixed wireless network, a wireless local area network (LAN), a wireless wide area network (WAN), a personal area network (PAN), a virtual private network (VPN), an intranet, or other suitable network system, and include devices for receiving and transmitting signals.

[0148] The network may also be an IP-based network for communicating between a given unit and any external servers, clients, etc. via a broadband connection. In an exemplary embodiment, the network may be a managed IP network managed by a service provider. Additionally, the network may be a packet-switched network such as a LAN, WAN, Internet network, etc.

[0149] If the unit is a PC, workstation, smart device, etc., the software in the memory may also include a basic input and output system (BIOS). The BIOS is stored in ROM so that it can be executed when the computer is activated.

[0150] When the unit is running, the processor is configured to execute software stored in the memory, transfer data to and from the memory, and generally control the operation of the computer according to the software. The methods and OS described herein are read in whole or in part by the processor, typically buffered within the processor, and then executed. When the methods described herein are implemented in software, the methods can be stored on any computer-readable medium (e.g., a storage device) for use with or in conjunction with any computer-related system or method.

[0151] Cloud Computing Overview

[0152] It should be understood that although the present disclosure includes detailed descriptions about cloud computing, the implementation of the teachings given herein is not limited to cloud computing environments. Instead, embodiments of the present invention can be implemented in conjunction with any other type of computing environment now known or later developed.

[0153] Cloud computing is a service delivery model that enables convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be quickly provisioned and released with minimal management effort or interaction with the service provider. The cloud model can include at least five characteristics, at least three service models, and at least four deployment models.

[0154] Features are as follows:

[0155] On-demand self-service: Cloud consumers can unilaterally and automatically provision computing capabilities, such as server time and network storage, as needed, without requiring human interaction with the service provider.

[0156] Broad Network Access: Capabilities are available over the network and accessed through standard mechanisms that facilitate the use of heterogeneous thin-client or thick-client platforms (e.g., mobile phones, laptops, and PDAs).

[0157] Resource pooling: A provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, where different physical and virtual resources are dynamically assigned and reassigned as needed. There is a sense of location independence, as consumers typically do not have control or knowledge of the exact location of the provided resources, but may be able to specify the location at a higher level of abstraction (e.g., country, state, or data center).

[0158] Rapid elasticity: The ability to quickly and elastically provision capacity, in some cases automatically scaling down and releasing capacity to scale up quickly. To the consumer, the capacity available for provisioning typically appears unlimited and can be purchased in any quantity at any time.

[0159] Metered Services: Cloud systems automatically control and optimize resource usage by leveraging metering capabilities at a level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency to both providers and consumers of the utilized services.

[0160] The service model is as follows:

[0161] Software as a Service (SaaS): The ability provided to consumers is to use the provider's applications running on a cloud infrastructure. Applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based email). Consumers do not manage or control the underlying cloud infrastructure, including networks, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.

[0162] Platform as a Service (PaaS): The capability provided to consumers is to deploy applications created or acquired using programming languages ​​and tools supported by the provider onto cloud infrastructure. Consumers do not manage or control the underlying cloud infrastructure, including networks, servers, operating systems, or storage, but do have control over the deployed applications and the configuration of the application hosting environment.

[0163] Infrastructure as a Service (IaaS): The capabilities provided to consumers are processing, storage, networking, and other basic computing resources on which consumers can deploy and run arbitrary software, including operating systems and applications. Consumers do not manage or control the underlying cloud infrastructure, but rather have control over the operating system, storage, deployed applications, and potentially limited control over selected networking components (e.g., host firewalls).

[0164] The deployment model is as follows:

[0165] Private cloud: Cloud infrastructure is operated solely for an organization. It can be managed by the organization or a third party and can exist on-premises or off-premises.

[0166] Community cloud: Cloud infrastructure is shared by several organizations and supports a specific community with shared concerns (e.g., mission, security requirements, policies, and compliance considerations). It can be managed by the organization or a third party and can exist on-premises or off-premises.

[0167] Public cloud: Cloud infrastructure is made available to the public or large industry groups and is owned by the organization that sells cloud services.

[0168] Hybrid cloud: A cloud infrastructure is a combination of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technologies that enable data and application portability (e.g., cloud bursting for load balancing between clouds).

[0169] Cloud computing environments are service-oriented and focus on statelessness, low coupling, modularity, and semantic interoperability. The core of cloud computing is the infrastructure that consists of a network of interconnected nodes.

[0170] Now see Figure 8A , describes an illustrative cloud computing environment 850. As shown, the cloud computing environment 850 includes one or more cloud computing nodes 810 with which local computing devices used by cloud consumers can communicate, such as, for example, personal digital assistants (PDAs) or cellular phones 854A, desktop computers 854B, laptop computers 854C, and / or automobile computer systems 854N. The nodes 810 can communicate with each other. They can be grouped physically or virtually (not shown) in one or more networks, such as private clouds, community clouds, public clouds, or hybrid clouds, or a combination thereof, as described above. This allows the cloud computing environment 850 to provide infrastructure, platforms, and / or software as services for which cloud consumers do not need to maintain resources on local computing devices. It should be understood that Figure 8A The types of computing devices 854A-N shown in are intended to be illustrative only, and computing node 810 and cloud computing environment 850 may communicate with any type of computerized device over any type of network and / or network-addressable connection (eg, using a web browser).

[0171] Now see Figure 8B , showing the cloud computing environment 850 ( Figure 8A ) provides a set of functional abstraction layers. It should be understood in advance that Figure 2 The components, layers, and functions shown in the figure are intended to be illustrative only, and embodiments of the present invention are not limited thereto. As shown in the figure, the following layers and corresponding functions are provided:

[0172] The hardware and software layer 860 includes hardware and software components. Examples of hardware components include: mainframes 861; servers based on RISC (Reduced Instruction Set Computer) architecture 862; servers 863; blade servers 864; storage devices 865; and network and networking components 866. In some embodiments, software components include network application server software 867 and database software 868.

[0173] The virtualization layer 870 provides an abstraction layer from which the following examples of virtual entities can be provided: virtual servers 871 ; virtual storage 872 ; virtual networks 873 , including virtual private networks; virtual applications and operating systems 874 ; and virtual clients 875 .

[0174] In one example, the management layer 880 may provide the functionality described below. Resource provisioning 881 provides dynamic procurement of computing resources and other resources for performing tasks within a cloud computing environment. Metering and pricing 882 provides cost tracking when resources are utilized within the cloud computing environment and bills or invoices for the consumption of these resources. In one example, these resources may include application software licenses. Security provides authentication for cloud consumers and tasks, as well as protection for data and other resources. User portal 883 provides access to the cloud computing environment for consumers and system administrators. Service level management 884 provides cloud computing resource allocation and management so that required service levels are met. Service level agreement (SLA) planning and fulfillment 885 provides pre-arrangement and procurement of cloud computing resources in anticipation of future demand according to the SLA.

[0175] The workload layer 890 provides examples of functionality that can utilize a cloud computing environment. Examples of workloads and functionality that can be provided from this layer include: mapping and navigation 891; software development and lifecycle management 892; virtual classroom instructional delivery 893; data analytics processing 894; transaction processing 895; and mobile desktop 896.

[0176] It should be understood that although the present disclosure relates to cloud computing, implementation of the teachings described herein is not limited to a cloud computing environment. Rather, embodiments of the present invention can be implemented in conjunction with any other type of computing environment now known or later developed. Cloud computing is a service delivery model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be quickly provisioned and released with minimal management effort or interaction with the provider of the services. The cloud model can include at least five characteristics, at least three service models, and at least four deployment models.

[0177] Although the present invention has been described with reference to a limited number of embodiments, variants and drawings, it will be understood by those skilled in the art that different changes may be made and equivalents may be substituted without departing from the scope of the present invention. In particular, the features (device type or method type) described in a given embodiment, variant or shown in the drawings may be combined with or replace another feature in another embodiment, variant or drawing without departing from the scope of the present invention. Therefore, various combinations of the features described with respect to any of the above-mentioned embodiments or variants are conceivable, and these combinations are still within the scope of the appended claims. In addition, many minor modifications may be made to adapt specific circumstances or materials to the teachings of the present invention without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the specific embodiments disclosed, but will include all embodiments falling within the scope of the appended claims. In addition, many other variations other than those explicitly mentioned above may be conceivable.

Claims

1. A method for interpreting an optical characterization inspection, wherein the optical characterization inspection is performed by a set of devices: in, Each device in the group: comprising one or more optical element surface structure arrays; as well as There are corresponding arrays with different characteristics; The method includes, for each device in the group: accessing first data and second data capturing a physical fingerprint of each device and results of an optical characterization inspection performed with each device, respectively, wherein the results are influenced by respective ones of the different characteristics; identifying each device based on the accessed first data to obtain a readout key associated with the identified device, the readout key interpreting a corresponding characteristic among the different characteristics; interpreting second data based on the readout key to illustrate a result of the optical characterization inspection; and The results of the optical characterization inspection are sent to an inspection device.

2. The method according to claim 1, wherein: The results are influenced by both respective ones of the different characteristics and a physical fingerprint of each device; the readout key interpreting both corresponding ones of the different characteristics and a physical fingerprint of each device; as well as Accessing the first and second data includes: receiving characteristic data; as well as In view of identifying each device, the first and second data are determined based on the received characterizing data to obtain an associated readout key and to interpret the second data according to the obtained readout key.

3. The method according to claim 2, wherein: A physical fingerprint is an unclonable characteristic of one or more arrays of each device.

4. The method according to claim 1, wherein In order to make the devices of the group different from each other, the devices of the group each comprise two or more meta-surface structure arrays having different properties.

5. The method according to claim 4, wherein: The elemental surface structures of at least one array of each device are coated with a substance for selectively binding an analyte, said substance forming a corresponding functionalized pattern of the array of said device; for each device, a result captured by the second data being influenced by both the metasurface structure of the respective array of each device and the respective one of the functionalized patterns; as well as The readout key interprets a corresponding one of the functionalized patterns.

6. The method according to claim 5, wherein: The substance comprises molecular receptors for selectively binding the analyte, and the elemental surface structures of at least one array of each device are coated with the molecular receptors so as to functionalize the array of the device according to a corresponding functionalization pattern formed by the molecular receptors.

7. The method according to claim 6, wherein: Two or more arrays per device are coated with different types of molecular receptors for selectively binding different types of analytes.

8. The method according to claim 6, wherein: The receptors are formed as molecular compounds immobilized on the surface of the one or more metasurface structures, and each of the molecular compounds comprises several parts, including a first part anchored to the surface and a second part that is a receptor chemically linked to the first anchoring part via a backbone.

9. The method according to claim 8, wherein: The plurality of moieties further include a third moiety which is a protecting moiety for acetylene, the protecting moiety being bound to the acetylene unit of the backbone of each of the molecular compounds via an electrochemically cleavable bond; as well as The method further comprises deprotecting the acetylene unit of the backbone of the molecular compound by electrochemically cleaving its protecting moiety before binding the molecular receptor to the deprotected acetylene unit.

10. The method according to claim 1, wherein The results of the optical characterization inspection include optical data representing the spectral response of each device.

11. The method according to claim 10, further comprising: For each device, and before accessing the first and second data, the optical characterization check is performed by illuminating each array of each device with electromagnetic radiation at a frequency matching the resonant frequency of the metasurface structure of the array in the absence of analyte.

12. The method according to claim 10, wherein: The spectral response is a response to electromagnetic radiation transmitted through each device, the spectral response reflecting changes in absorption resonance caused by effective changes in the dielectric environment of the metasurface structures in one or more arrays of the devices.

13. The method of claim 1, wherein: The method is performed at a server in data communication with a group of client devices; as well as The method further comprises, for each device and before accessing the first data and the second data, receiving data from one of the client devices paired with each device, the first data and the second data being accessible by the server based on the received data, so that the server identifies each device based on the accessed first data and interprets the second data according to the readout key obtained accordingly.

14. The method according to claim 13, further comprising: After each device has been identified and the second data interpreted to clarify the results of the optical characterization inspection, a message is sent to one of the client devices, the message including information regarding the clarified results.

15. The method of claim 1 , further comprising, for each device in the group and before accessing the first data and the second data for any device in the group: manufacturing each device so that one or more arrays of each device have corresponding ones of the different characteristics; and A readout key for a corresponding one of the different characteristics is associated with an identifier for each device.

16. The method according to claim 15, further comprising: After manufacturing each device and before accessing the first data and the second data of any device in the group, the physical fingerprint of each device is read to obtain a digital fingerprint corresponding to the physical fingerprint and the digital fingerprint is associated with an identifier of each device.

17. The method according to claim 1, wherein Each array of each of the devices comprises a pattern of repeating units each having two elemental surface structures.

18. The method of claim 1, wherein: forming a metasurface structure as a semiconductor layer structure arranged on top of a substrate; and The semiconductor layer structures each have lateral dimensions, measured parallel to the main surface of the substrate, of an average of between 1 nm and 500 nm.

19. The method according to claim 18, wherein The semiconductor layer structures each have a vertical dimension, measured perpendicularly to the main surface of the substrate, which on average is between 10 nm and 500 nm, with a standard deviation of less than 5 nm.

20. A computer program product for interpreting an optical characterization inspection, wherein the optical characterization inspection is performed by a set of devices, each device comprising one or more arrays of electromagnetic surface structures, wherein: customizing the devices so that their respective arrays have different characteristics, wherein the computer program product comprises a computer-readable storage medium having program instructions embodied therein, the program instructions being executable by a processing device to cause the latter to, for each device in the group: accessing first data and second data capturing a physical fingerprint of each device and results of an optical characterization inspection performed with each device, respectively, wherein the results are influenced by respective ones of the different characteristics; identifying each device based on the accessed first data to obtain a readout key associated with the identified device, the readout key interpreting a corresponding characteristic among the different characteristics; interpreting second data based on the readout key to illustrate a result of the optical characterization inspection; and The results of the optical characterization inspection are sent to an inspection device.

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