Abstract: A print on-demand color shift material which has high reflection, high saturation color and intrinsic, high impact color-shift produced by thermal printing or laser writing for use, for example in security laminates, tax and excise stamps, machine-readable features and banknote foils, and offering a rainbow of colors with full color shifting, producible in full manufacturing scale.

Abstract: Methods and systems for thermal printing of thermally printable photonic crystal materials and assemblies. The photonic crystal materials and assemblies are responsive to thermal stimuli, wherein temperatures above a thermal threshold results in an optically detectable change in the appearance of the materials and assemblies. Heat is selectively applied to one or more portions of the materials and assemblies, in order to thermally print a graphic onto the materials and assemblies.

Abstract: A temperature-responsive photonic crystal device comprising having a temperature-responsive photonic crystal material, whereby exposure of the device to a temperature above a predetermined threshold temperature is indicated by a detectable change in the device.

Abstract: A light-scattering photonic material is disclosed having a matrix defining a plurality of disordered voids. The material may be reversibly responsive to an external stimulus, exhibiting reversible first and second optical effects. The material may be a thin film material.

Abstract: The present disclosure provides methods, systems and devices for a photonic crystal combinatorial sensor. The photonic crystal sensor may include an array of photonic crystal materials, wherein each photonic crystal material has a reflected wavelength in a respective initial wavelength range. At least one a first one of the photonic crystal materials may be configured to have a response to an external stimulus different from at least a second one of the photonic crystal materials, the different response resulting in a change in the reflected wavelength of the first photonic crystal material that is an optically detectable difference from the second photonic crystal material. The optically detectable difference may provide an optically detectable response pattern of reflected wavelengths in the array. The sensor may be reversible and reusable.

Abstract: A photonic crystal electrical property indicator for a battery comprising: an electrically conductive working electrode and an electrically conductive counter electrode; an electrically-responsive photonic crystal material in contact with at least one of said first and second electrically conductive electrodes; an ionically conductive electrolyte provided between the working and counter electrodes; and electrical conductors for connecting the indicator to terminals of the battery; wherein the photonic crystal material has a reflectance spectrum that is responsive to a change in at least one electrical property of the battery, thereby providing an optically detectable indication of the at least one electrical property of the battery.

Abstract: A tunable photonic crystal composition comprising: tunable photonic crystal particles having a polymer network with a periodic modulation of refractive indices, the polymer network having a reflectance wavelength, wherein the periodic modulation of refractive indices is responsive to an external stimulus and the reflectance wavelength is shifted in response to the external stimulus; and a carrier in which the particles are dispersed.

Abstract: A tunable photonic crystal device comprising: alternating layers of a first material and a second material, the alternating layers comprising a responsive material, the responsive material being responsive to an external stimulus, the alternating layers having a periodic difference in refractive indices giving rise to a first reflected wavelength; wherein, in response to the external stimulus, a change in the responsive material results in a reflected wavelength of the device shifting from the first reflected wavelength to a second reflected wavelength.

Abstract: A photonic crystal device including a photonic crystal material and an activation surface. The photonic crystal material exhibits a first reflectance spectrum in an unactivated state, and, in response to mechanical stimulation, exhibits a second reflectance spectrum in an activated state. Application of a force at an activation portion of the activation surface offset from a material-supporting portion of the activation surface causes a deformation of the photonic crystal material sufficient to bring the photonic crystal material to the activated state.

Abstract: Methods and systems for thermal printing of thermally printable photonic crystal materials and assemblies. The photonic crystal materials and assemblies are responsive to thermal stimuli, wherein temperatures above a thermal threshold results in an optically detectable change in the appearance of the materials and assemblies. Heat is selectively applied to one or more portions of the materials and assemblies, in order to thermally print a graphic onto the materials and assemblies.

Abstract: A photonic crystal device comprising: a photonic crystal material having an initial ordered structure and a viewing surface, the initial ordered structure giving rise to a first optical effect detectable from the viewing surface; and a removal layer removably attached with the viewing surface or an opposing surface of the photonic crystal material opposite to the viewing surface; wherein mechanical removal of at least a portion of the removal layer results in a structural change in at least a portion of the initial ordered structure of at least a portion of the photonic crystal material respective to the portion of the removed removal layer, thereby resulting in a changed portion different from the initial ordered structure, the changed portion giving rise to a second optical effect detectable from the viewing surface and detectably different from the first optical effect.

Abstract: A tunable photonic crystal device comprising: alternating layers of a first material and a second material, the alternating layers comprising a responsive material, the responsive material being responsive to an external stimulus, the alternating layers having a periodic difference in refractive indices giving rise to a first reflected wavelength; wherein, in response to the external stimulus, a change in the responsive material results in a reflected wavelength of the device shifting from the first reflected wavelength to a second reflected wavelength.

Abstract: A photonic crystal device including a photonic crystal material and an infiltrating component. The photonic crystal material has an initial reflectance spectrum. An external stimulus causes the infiltrating component to migrate into or out of at least a portion of the photonic crystal material. The migration of the infiltrating component causes a change of at least the portion of the photonic crystal material to shift to a second reflectance spectrum.

Abstract: A compressible photonic crystal comprising a polymer with an ordered array of voids, the photonic crystal having a reflectance in a first wavelength range for light incident to its incident surface and its opposing incident surface; wherein compression against at least a portion of at least one of the surfaces shifts the reflectance to a second wavelength range in at least that portion of that surface. The crystal may be used in authentication devices of various types.

Abstract: A light-scattering photonic material is disclosed having a matrix defining a plurality of disordered voids. The material may be reversibly responsive to an external stimulus, exhibiting reversible first and second optical effects. The material may be a thin film material.

Abstract: A photonic crystal device including a photonic crystal material and an activation surface. The photonic crystal material exhibits a first reflectance spectrum in an unactivated state, and, in response to mechanical stimulation, exhibits a second reflectance spectrum in an activated state. Application of a force at an activation portion of the activation surface offset from a material-supporting portion of the activation surface causes a deformation of the photonic crystal material sufficient to bring the photonic crystal material to the activated state.

Abstract: A security and/or authentication device comprising: a compressible photonic crystal having an ordered array of voids, the photonic crystal having a reflection peak, wherein compression against at least a portion photonic crystal results in a decrease of intensity of the reflection peak in at least that portion.

Abstract: The present disclosure provides methods, systems and devices for a photonic crystal combinatorial sensor. The photonic crystal sensor may include an array of photonic crystal materials, wherein each photonic crystal material has a reflected wavelength in a respective initial wavelength range. At least one a first one of the photonic crystal materials may be configured to have a response to an external stimulus different from at least a second one of the photonic crystal materials, the different response resulting in a change in the reflected wavelength of the first photonic crystal material that is an optically detectable difference from the second photonic crystal material. The optically detectable difference may provide an optically detectable response pattern of reflected wavelengths in the array. The sensor may be reversible and reusable.

Abstract: A photonic crystal incandescent light source comprising: a photonic crystal having a structure configured to reflect wavelengths from at least a portion of an infrared spectrum; and an incandescent central filament in the photonic crystal, causing the photonic crystal to transmit wavelengths from at least a portion of a visible spectrum; wherein the light source emits at least a portion of visible wavelengths and suppresses emission of at least a portion of infrared wavelengths.

Abstract: A temperature-responsive photonic crystal device comprising having a temperature-responsive photonic crystal material, whereby exposure of the device to a temperature above a predetermined threshold temperature is indicated by a detectable change in the device.