EP3183606A1 - Revêtement réfléchissant flexible et réglable - Google Patents

Revêtement réfléchissant flexible et réglable

Info

Publication number
EP3183606A1
EP3183606A1 EP15756516.9A EP15756516A EP3183606A1 EP 3183606 A1 EP3183606 A1 EP 3183606A1 EP 15756516 A EP15756516 A EP 15756516A EP 3183606 A1 EP3183606 A1 EP 3183606A1
Authority
EP
European Patent Office
Prior art keywords
skin
film
reflectivity
layer
layers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP15756516.9A
Other languages
German (de)
English (en)
Inventor
Allan James Bruce
Michael Cyrus
Sergey Frolov
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sunlight Aerospace Inc
Original Assignee
Sunlight Photonics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sunlight Photonics Inc filed Critical Sunlight Photonics Inc
Publication of EP3183606A1 publication Critical patent/EP3183606A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1828—Diffraction gratings having means for producing variable diffraction
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/26—Reflecting filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters

Definitions

  • the present invention relates to the structure and functionality of a freestanding skin which is flexible and exhibits settable or tunable reflectivity when the skin is stretched, flexed or otherwise changed in shape.
  • the skin may be used for a number of applications including dynamic camouflage, reflective tagging and optical filtering.
  • Reflection When light of given wavelength (lambda) is incident on a material or structure, it is reflected transmitted or absorbed to various, and complementing degrees. Reflection may be mirror-like (specular), with an angular dependence, or diffuse (scattered), without a specific angular dependence, or a combination of both. Reflection may occur at the surface without significant light penetration of the material, within a material layer immediate to the surface or at sub-surface interfaces or structures.
  • Reflective coatings and structures typically have fixed dimensions and are used on fixed structures or devices. Examples include Multi-layer Interference Reflectors and Grating Reflectors. Multi-layer Interference Reflectors are used for both AR and reflection applications. The dimensionality of a multi-layer stack impacts the reflectivity and the wavelength dependence.
  • Grating Reflectors are typically comprised of ID and 2D structures defined on the surface, or within, a device. If the grating period is much smaller than the wavelength of the incident light (sub-wavelength), the grating behaves like a homogeneous material.
  • Tunable reflectivity has been shown for a number of devices and structures. For example, tuning by thermal and electrical means in VCSELs has been
  • Tunable reflectivity requires a capacity for altering reflectivity and a control mechanism.
  • _Applications in which it is desirable to be able to set or dynamically tune the reflective properties of a surface or structure include (i) dynamic camouflage, where reflections are used to mimic physical surroundings, (ii) dynamic optical tagging, where activated retro-reflectivity is used for identification purposes and (iii) optical switches, attenuators and filters for emitters, sensors and analogous devices.
  • Various applications employ articles such as skins which have significant specular or diffuse reflection.
  • the invention provides skins that are mechanically durable and which exhibit settable or tunable reflection when subject to changes in shape or physical dimensions.
  • Embodiments include skins with stacked sub-wavelength layers and nano-, or micro-, structures which experience dimensional changes and exhibit changeable reflectivity when the skins are stretched, flexed or otherwise changed in shape. In their original state the skins may be transmitting, reflecting or partially both.
  • the invention features a free-standing film or self-supporting film or skin which is flexible, stretchable and exhibits optical reflectivity in its original or stretched state.
  • the skin is distinguished from conventional reflectors in that it is specifically designed to be mechanically durable and alter its reflectivity when stretched or flexed.
  • the materials, structure and optical design are selected, or engineered, such that any critical values of dimension, refractive index or other essential characteristics are achieved during deformation.
  • a variety of flexible and transparent base materials including polymers and fluoro-polymers and standard engineering and design methods may be employed to achieve the desired characteristics.
  • the latter includes single- or multi-layer structures, doped, composite and nano-structured layers or surfaces.
  • the achievable reflectivity characteristics are appropriate for a wide range of devices.
  • the invention features tunable reflectivity characteristics achieved by stretching or flexing the skin.
  • the structure and reflectivity design of the skin is engineered to have a level of sensitivity to a defined deformation.
  • This approach can be used to provide the ability to optimize performance at different wavelengths of light, filter light to, or from an underlying device, and implement retro reflective tagging or reflective camouflage.
  • reflectors, or reflecting surfaces have a fixed reflectivity, fixed dimension and are fixed or set in their spatial relationship to a substrate, structure or device.
  • the skin in its entirety can be considered a reflector, which exhibits adjustable reflectivity, variable dimension and as a stand-alone article, it need not have a fixed spatial relationship to a substrate, structure or device.
  • Figures 1(a) and 1(b) show a schematic representation of a multi-layer skin, with an optical interference stack.
  • Figures 2(a) and 2(b) show another schematic representation of a skin, with a ID grating on the surface.
  • FIG. 3 shows a skin having a plurality of layers 202, 204 and 206.
  • the discrete skins may have physical structures which are resilient to significant mechanical or functional degradation or failure when stretched and, or flexed in the course of deployment or use. They may be comprised of ductile materials, if a single deployment is sufficient, or elastic materials if repeated or continuous bi-directional modification is required during use. In cases where the skin is comprised of multiple-layers the physical properties of the constituent layers should be sufficiently similar to maintain the integrity of the skin under conditions of use without mechanical, or functional, degradation. Examples of suitable skin materials include standard polymeric materials which meet the requirements of the application.
  • the preferred skins may comprise appropriate materials or surfaces to be able to function as discrete elements, such as structural skins, or to interface with supporting structures or surrounding media.
  • Such interfacing may be achieved in a number of conventional ways by chemical, thermal, mechanical, electrical or other means and may include optional surface layers or materials to assist the interfacing process. Examples of such surface layers include layers comprised of standard adhesives.
  • the skins may have any of a number of transverse structures which enable the desired reflectivity. They may be comprised of mono-layers, which have constant, graded or varied refractive index. They may be comprised of a multi-layer where the layers have an engineered progression of refractive index. They may include nano- composite layers or nano-structured surfaces which may provide a wider range of engineered refractive index profiles than dense or single material layers.
  • the skins may incorporate an interference stack of materials which change reflectivity when subject to flexing and stretching.
  • the skins may also include grating structures, including sub-wavelength gratings, which exhibit varying reflectivity when stretched or flexed.
  • FIGs 1(a) and 1(b) show a schematic representation of a multi-layer skin, with an optical interference stack.
  • incident light Io
  • To incident light
  • Ro reflection
  • FIG. 1(b) the dimension of the interference stack is reduced, potentially also changing the refractive index of the materials, and the structure becomes more reflective and incident light (Ii) is substantially reflected (Ri) with little or no transmission (Ti).
  • the structure may be designed to be reflective in its initial state and transmitting when stretched.
  • the structure can also be designed to produce intermediate levels of transmission and reflection for a defined range of deformation.
  • Figures 2(a) and 2(b) shows an analogous representation of a skin, with a ID grating on the surface.
  • the skin may be designed to be transmitting.
  • the skin is stretched in FIG. 2(b) the dimension and periodicity of the grating changes and may become more reflective.
  • the skin may also be designed for the reverse behavior and intermediate performance. When the skin is flexed it can be simultaneously stretched or compressed in various regions which can produce more complex, but predictable, reflection characteristics.
  • Materials with suitable mechanical and optical properties include various polymers which are appropriately, elastic, or ductile. Depending on the optical structure employed they should also be suitable for chemical, or structural, modifiable to provide index variations, for patterning, or loading with a high index particles, including nano-particles. Examples include polymers which are polyethelene or polypropylene or fluoro-polymers such as ETFE and PVDF and structural or compositional modifications thereof, including composites, loaded with other materials or phases. Within a range the ETFE and modified derivatives can exhibit elastic behavior.
  • the flexible skin should be sufficiently reflective under the conditions of use for the desired electromagnetic frequencies which may be in the ultra-violet, visible or infra red regions of the spectrum. Embodiments with specular or diffuse reflective performance may be preferred.
  • the thickness, and reflectivity of the respective layers or structures in the flexible skin should be in a range that changes in these parameters induced by stretching or flexing during deployment, or use, are sufficient to significantly alter the reflectivity of the skin from its performance prior to deformation.
  • a multi-layer skin with an optical interference stack as shown in Figure 1 is provided.
  • a skin may consist of alternating layers of ETFE, with different levels of high-index, nano-particle material loading to establish a desired index contrast. In the unperturbed state this skin may be substantially transparent.
  • the periodicity of the interference stack will change and result in a change in the reflectivity of the skin.
  • the structure may initially be reflective and exhibit a change in transmission when stretched. The changes could be gradual or stepped in nature. If the skin is flexed, one surface may be stretched and the opposite surface compressed, producing more complex, but predictable, reflection characteristics. Asymmetric stretching could also be used to introduce, or change, the response to light of different polarizations.
  • a skin with a reflective grating on the surface as shown in Figure 2 is provided.
  • the grating could be ID, 2D or 3D in nature.
  • a skin may consist of a nano-structured layer, or layers of ETFE.
  • the skin In an unperturbed state the skin could be transmitting. When stretched the dimension and periodicity of the grating will increase and could become more reflective.
  • the skin may also be designed for the reverse behavior. These changes could be gradual or stepped in their response. When the skin is flexed it can be simultaneously stretched or compressed in various regions which can produce more complex, but predictable, reflection characteristics. Asymmetric stretching could also be used to introduce, or change, the response to light of different polarizations.
  • FIG. 3 shows a skin having a plurality of layers 202, 204 and 206, As shown, layers 204 and 206 include structured gratings. As further shown, layer 204 is subsurface layer.
  • Embodiments of the invention are directed to addressing reflective functionality, for applications involving non-planar, flexible, mobile and shape- changing substrates or platforms.
  • embodiments with specular or diffuse reflectivity may be preferred.
  • Embodiments for mobile platforms including cars, ships and planes can include non-planar surfaces (e.g. a car top or fuselage) and variations in the relative angle of incidence from a defined source during operation.
  • non-planar surfaces e.g. a car top or fuselage
  • Embodiments for platforms which change shape during use including inflatable or wearable platforms.
  • the skin should be elastic to allow for extended use.
  • Some embodiments provide the ability to tune or adjust the intensity and/or wavelength of reflectivity of a skin. Such preferred embodiments may involve sensitizing the skin design in terms of tailoring thickness and optical characteristics to be near some critical point for changing reflective performance by stretching, flexing or otherwise changing the shape of a skin within a range which is accessible by the influence of an external stimulus, which could include a mechanical, thermal or electrical means of controlled flexing or stretching of the skin. For example by inflation, or by activating a piezo-electric element to induce stretching to reduce the index and/or layer thickness below a critical value.
  • some embodiments may be used to tune the skin for optimized reflective performance at a given wavelength.
  • Other embodiments reduce transmission intensity by increasing reflectivity, for example, in order to prevent saturation of sensory devices.
  • Another embodiment allows adjustment of the wavelength, intensity or modulation of reflected light for optical tagging or camouflage applications.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)
  • Optical Filters (AREA)

Abstract

L'invention concerne des articles autonomes souples (revêtements) possédant une réflectivité réglable ou accordable pour une plage définie de fréquences électromagnétiques. Les articles comprennent une monocouche ou des couches multiples de matériaux élastiques ou ductiles qui conservent l'intégrité mécanique lorsque le revêtement est étiré, plié ou subit une autre modification de forme. Les articles peuvent en outre comprendre une structure optique qui présente une réflectivité modifiable lorsque le revêtement est étiré, plié ou subit une autre modification de forme. L'invention concerne également des procédés permettant de régler les caractéristiques réflectives de ce revêtement par étirement, pliage ou un autre procédé de modification de la forme.
EP15756516.9A 2014-08-22 2015-08-14 Revêtement réfléchissant flexible et réglable Ceased EP3183606A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201414466931A 2014-08-22 2014-08-22
PCT/US2015/045328 WO2016028642A1 (fr) 2014-08-22 2015-08-14 Revêtement réfléchissant flexible et réglable

Publications (1)

Publication Number Publication Date
EP3183606A1 true EP3183606A1 (fr) 2017-06-28

Family

ID=54011893

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15756516.9A Ceased EP3183606A1 (fr) 2014-08-22 2015-08-14 Revêtement réfléchissant flexible et réglable

Country Status (2)

Country Link
EP (1) EP3183606A1 (fr)
WO (1) WO2016028642A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11042047B1 (en) 2014-08-22 2021-06-22 Sunlight Aerospace Inc. Mobile system incorporating flexible and tunable optically reflective skin and method of use
GB2548658B (en) * 2016-03-24 2020-09-09 Bae Systems Plc Filters for laser protection
CN112859223A (zh) * 2021-01-25 2021-05-28 上海交通大学 表面褶皱机械复合光栅系统及调谐方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4937134A (en) * 1989-04-17 1990-06-26 The Dow Chemical Company Elastomeric optical interference films
EP1122577A2 (fr) * 2000-01-26 2001-08-08 Eastman Kodak Company Modulateur spatial de lumière avec dispositif de réseau conforme
US20100149647A1 (en) * 2008-10-24 2010-06-17 Efrain Figueroa System Method and Apparatus for Selecting and Controlling Light Source Bandwidth
WO2013083624A1 (fr) * 2011-12-05 2013-06-13 Wise S.R.L. Procédé de production d'éléments optiques étirables et déformables, et éléments ainsi obtenus

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5339198A (en) * 1992-10-16 1994-08-16 The Dow Chemical Company All-polymeric cold mirror
US6856461B2 (en) * 2001-06-08 2005-02-15 Inphase Technologies, Inc. Tunable optical filter
US7283716B2 (en) * 2003-10-21 2007-10-16 The Regents Of The University Of Colorado Strain tunable, flexible photonic crystals
AU2007346889B2 (en) * 2007-02-16 2014-05-15 Opalux Incorporated Compressible photonic crystal
US9074090B2 (en) * 2011-04-15 2015-07-07 GM Global Technology Operations LLC Shape memory polymer-based tunable photonic device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4937134A (en) * 1989-04-17 1990-06-26 The Dow Chemical Company Elastomeric optical interference films
EP1122577A2 (fr) * 2000-01-26 2001-08-08 Eastman Kodak Company Modulateur spatial de lumière avec dispositif de réseau conforme
US20100149647A1 (en) * 2008-10-24 2010-06-17 Efrain Figueroa System Method and Apparatus for Selecting and Controlling Light Source Bandwidth
WO2013083624A1 (fr) * 2011-12-05 2013-06-13 Wise S.R.L. Procédé de production d'éléments optiques étirables et déformables, et éléments ainsi obtenus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2016028642A1 *

Also Published As

Publication number Publication date
WO2016028642A1 (fr) 2016-02-25

Similar Documents

Publication Publication Date Title
US20190146133A1 (en) Filter Made of Metamaterials
Jeong et al. 3D and 4D printing for optics and metaphotonics
KR102189096B1 (ko) 가식 시트, 액정 표시 장치 및 자동차 차내용 내장
KR20170070138A (ko) 중첩 고조파를 갖는 다층 광학 필름
US9453947B2 (en) Flat retroreflectors
WO2016028642A1 (fr) Revêtement réfléchissant flexible et réglable
US11977207B2 (en) Adaptive materials and systems for manipulation of electromagnetic radiation
JPH07507152A (ja) 全ポリマー紫外線反射フィルム
CN107076899B (zh) 方向选择性干涉式光学滤波器
WO2012096702A2 (fr) Structures de protection laser et procédés de fabrication
CN111066313B (zh) 摄像装置
CN106030353B (zh) 偏振板、光学构件组及触摸输入式图像显示装置
Cai et al. Diphylleia grayi-inspired stretchable hydrochromics with large optical modulation in the visible–near-infrared region
KR101902659B1 (ko) 단속된 금속성 층으로 코팅된 표면을 포함하는 태양광 관리를 위한 반투명 건축 요소
CN111344610A (zh) 反射片、装饰片及反射片的制造方法
WO2012147052A1 (fr) Réflecteurs infrarouges servant à la gestion de la lumière solaire
Qu et al. Directional and spectral control of thermal emission and its application in radiative cooling and infrared light sources
EP3195024A1 (fr) Revêtement anti-réfléchissant souple et réglable
EP3032292B1 (fr) Composites à plage de température et plage de contrainte élevées, sur la base de matrices transparentes ayant des indices de réfraction syntonisable optiquement
JP6840235B2 (ja) 加飾シート、光学デバイス、画像表示装置
WO2009039354A3 (fr) Miroirs de bragg diélectriques hybrides organiques-inorganiques et leurs procédés d'utilisation
CN108627900A (zh) 光学相位差构件、偏光变换元件、模板及光学相位差构件的制造方法
US20130077165A1 (en) Vehicle display mirror and method of manufacturing the same
TWI485316B (zh) 具隔熱光導膜的裝置
Shrestha Smart window for tuning transparency and noise absorption

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20170322

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20190617

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SUNLIGHT AEROSPACE INC.

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

REG Reference to a national code

Ref country code: DE

Ref legal event code: R003

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 20231103