Polymer microparticles spatially and spectrally encoded using upconversion nanocrystals (UCN) are described for labeling of articles and tissues. UCN having spectrally distinguishable emission spectra are disposed in different portions of an encoding region of each microparticle.

Polymer microparticles spatially and spectrally encoded using upconversion nanocrystals (UCN) are described for labeling of articles and tissues. UCN having spectrally distinguishable emission spectra are disposed in different portions of an encoding region of each microparticle.

An improved system and method for reading an upconversion response from nanoparticle inks is provided. A is adapted to direct a near-infrared excitation wavelength at a readable indicia, resulting in a near-infrared emission wavelength created by the upconverting nanoparticle inks. A short pass filter may filter the near-infrared excitation wavelength. A camera is in operable communication with the short pass filter and receives the near-infrared emission wavelength of the readable indicia. The system may further include an integrated circuit adapted to receive the near-infrared emission wavelength from the camera and generate a corresponding signal. A readable application may be in operable communication with the integrated circuit. The readable application receives the corresponding signal, manipulates the signal, decodes the signal into an output, and displays and/or stores the output.

A security print medium for forming security documents therefrom, the security print medium comprising a core having opposing first and second sides. The core comprises a radiation-responsive substance distributed within the core across at least a first region of the core, the radiation-responsive substance being responsive to a predetermined input radiation by producing a predetermined output radiation. The security print medium further comprises a first encoding layer disposed on the first side of the core and a second encoding layer disposed on the second side of the core, each of the first and second encoding layers comprising an encoding material that modifies the intensity of the predetermined input radiation and/or the predetermined output radiation produced by the radiation-responsive substance transmitted through the respective encoding layer, wherein the first and second encoding layers overlap each other across the first region. The optical density of each of the first and second encoding layers varies across the first region in accordance with a predetermined pattern, the predetermined pattern defining one or more encoding features, such that when the security print medium is exposed to the predetermined input radiation, the output radiation detectable from one or each side of the security print medium varies across the first region in accordance with the one or more encoding features. The first and second encoding layers are configured such that when the security print medium is viewed in transmitted visible light, the intensity of visible light transmitted through the first encoding layer, the core and the second encoding layer in combination is uniform across the first region, such that the one or more encoding features is concealed.

A security print medium for forming security documents therefrom, the security print medium comprising a core having opposing first and second sides. The core comprises a radiation-responsive substance distributed within the core across at least a first region of the core, the radiation-responsive substance being responsive to a predetermined input radiation by producing a predetermined output radiation. The security print medium further comprises a first encoding layer disposed on the first side of the core and a second encoding layer disposed on the second side of the core, each of the first and second encoding layers comprising an encoding material that modifies the intensity of the predetermined input radiation and/or the predetermined output radiation produced by the radiation-responsive substance transmitted through the respective encoding layer, wherein the first and second encoding layers overlap each other across the first region. The optical density of each of the first and second encoding layers varies across the first region in accordance with a predetermined pattern, the predetermined pattern defining one or more encoding features, such that when the security print medium is exposed to the predetermined input radiation, the output radiation detectable from one or each side of the security print medium varies across the first region in accordance with the one or more encoding features. The first and second encoding layers are configured such that when the security print medium is viewed in transmitted visible light, the intensity of visible light transmitted through the first encoding layer, the core and the second encoding layer in combination is uniform across the first region, such that the one or more encoding features is concealed.

Systems and methods for utilizing one or more cameras at a mobile device to assist in the implementing anti-counterfeit measures for digital barcodes are disclosed. For example, the systems and methods use a mobile device's front camera to capture photographs (or images) at a certain frequency (e.g., capture a photograph every 0.20 seconds). The systems and methods then scan the captured photograph and retrieve relevant image data (for example, scan image vertically and utilize image data of every fourth pixel). The systems and methods compare certain properties of the retrieved image data with properties of one or more comparison light sources. When the systems and methods detect a match (for example, a match within certain threshold parameters), they identify a barcode among a set of barcodes and display the identified barcode at a display screen of the mobile device.

A method for authenticating an object, comprising determining a physical dispersion pattern of a set of elements, determining a physical characteristic of the set of elements which is distinct from a physical characteristic producible by a transfer printing technology, determining a digital code associated with the object defining the physical dispersion pattern, and authenticating the object by verifying a correspondence of the digital code with the physical dispersion pattern, and verifying the physical characteristic.

A method for authenticating an object, comprising determining a physical dispersion pattern of a set of elements, determining a physical characteristic of the set of elements which is distinct from a physical characteristic producible by a transfer printing technology, determining a digital code associated with the object defining the physical dispersion pattern, and authenticating the object by verifying a correspondence of the digital code with the physical dispersion pattern, and verifying the physical characteristic.

The invention provides a Raman-detectible composition comprising two or more different Raman-active 2D materials. Also provided is a formulation comprising the Raman-detectible composition and a binder; a substrate comprising the Raman-detectible composition; the use of the Raman-detectible composition to tag a substrate; a method for tagging a substrate with the Raman-detectible composition; and a method for analysing a substrate or formulation for the presence of the Raman detectible composition.

A system and method for authenticating an item, including a photoluminescent material disposed on or in a substrate and capable of absorbing an incident radiation from a radiation source and emitting an emitted radiation having a spectral signature with a decay time after removal of the radiation source, and a photoauthentication device capable of being disposed in contact with the substrate and including the radiation source and a camera, where, in connection with providing the incident radiation and measuring the emitted radiation, the photoauthentication device is translated across the substrate while the photoauthentication device is disposed in contact with the substrate, and after translation across or over the substrate and the radiation source is not providing the incident radiation, the photoauthentication device is static with respect to the substrate and the camera is disposed over the photoluminescent material emitting the emitted radiation when the emitted radiation is measured.