Patent Application
20180162615
The prototypical crease pattern object is generally referred to as origami. Typically, an origami is made from paper folded in certain ways. While pleasing to look at, an origami generally lacks strength.
Non-paper materials have been formed in crease patterns. For instance, solar panels for a space craft were assembled in a crease pattern so that they could be shipped into space in a folded conformation, and readily unfolded into a size that would have been too large for the space craft to carry. In this instance, a rigid material was formed into the crease pattern.
U.S. Pat. No. 7,521,292 to Rodgers describes a crease pattern made from elastomers. The crease patterns of this patent are described as flexible, however, the crease pattern of the objects described are very small. For instance, the patent refers to “a sine wave conformation with periodicities between about 500 nanometers and 100 microns, and preferably for some applications periodicities between about 5 microns to about 50 microns.”
A first embodiment of the present invention provides a polymeric component having a component wall thickness of between about 0.1 and 20 mm; a Shore durometer A scale value between about 15 and 85; and a repeating crease pattern. It is preferred that the component wall thickness is between about 0.5 and 10 mm.
A second embodiment of the present invention provides process for making a polymeric component wherein a solution of a polymeric reaction mixture is prepared; said polymeric reaction mixture is injected into a mold, said mold having a crease pattern shape; said polymeric reaction mixture is set/cured and then removed from said mold. In a preferred embodiment of the process for making the polymeric component, the setting reaction is carried out for between about 0.17 to 18 hours at a temperature of between about 55 and 80° F. In an alternative preferred embodiment of the process for making the polymeric component, the setting reaction is carried out for between about 5 and 30 minutes at a temperature of between about 190 and 440° F. In a further preferred embodiment, the setting reaction is carried out under conditions that reduce the air dissolved in the polymeric reaction mixture so as to provide a substantially air bubble free component, for instance by pressurizing the mold with the injected polymeric reaction mixture to a pressure of between about 200 and 2300 psig.
In further embodiments of the present invention, the polymeric component is incorporated into a floor mat; a container; a body part protector, or a tarp.
Referring to the drawings, like numerals indicate like elements and the same number appearing in more than one drawing refers to the same element. In addition, hereinafter, the following definitions apply:
The “wavelength” (or periodicity) of a crease pattern is the spatial period of the wave—the distance over which the wave's shape repeats—i.e., crest to crest or trough to trough.
“Component wall thickness” refers to the dimensions of a cross section of a wave of the crease pattern. Component wall thickness dimensions include width, thickness, radius, and diameter. For example, a polymeric component of the present invention having a ribbon shape is characterized by a length and two cross sectional dimensions: thickness and width.
“Substantially longitudinally oriented” refers to an orientation such that the longitudinal axes of a polymeric component of the present invention, are oriented substantially parallel to a selected alignment axis. In the context of this definition, substantially parallel to a selected axis refers to an orientation within 10 degrees of an absolutely parallel orientation, more preferably within 5 degrees of an absolutely parallel orientation.
“Stretchable” refers to the ability of a material, structure, device or device component to be strained without undergoing fracture. In an exemplary embodiment, a stretchable material, structure, device or device component may undergo strain larger than about 0.5% without fracturing, preferably for some applications strain larger than about 1% without fracturing and more preferably for some applications strain larger than about 3% without fracturing. In some embodiments of the present invention, the material of the present invention can be stretched more than 300% in any direction. However, at present, no embodiment of the present invention has been able to be stretched by more than about 450% in a single direction.
The terms “flexible” and “bendable” are used synonymously in the present description and refer to the ability of a material, structure, device or device component to be deformed into a curved shape without undergoing a transformation that introduces significant strain, such as strain characterizing the failure point of a material, structure, device or device component. In an exemplary embodiment, a flexible material, structure, device or device component may be deformed into a curved shape without introducing strain larger than or equal to about 5%, preferably for some applications larger than or equal to about 1%, and more preferably for some applications larger than or equal to about 0.5%.
“Plastic” refers to any synthetic or naturally occurring material or combination of materials that can be molded or shaped, generally when heated, and hardened into a desired shape. Exemplary plastics useful in the devices and methods of the present invention include, but are not limited to, polymers, resins and cellulose derivatives. In the present description, the term plastic is intended to include composite plastic materials comprising one or more plastics with one or more additives, such as structural enhancers, fillers, fibers, plasticizers, stabilizers or additives which may provide desired chemical or physical properties.
“Polymer” refers to a molecule comprising a plurality of repeating chemical groups, typically referred to as monomers. Polymers are often characterized by high molecular masses. Polymers useable in the present invention may be organic polymers or inorganic polymers and may be in amorphous, semi-amorphous, crystalline or partially crystalline states. Polymers may comprise monomers having the same chemical composition or may comprise a plurality of monomers having different chemical compositions, such as a copolymer. Cross linked polymers having linked monomer chains are particularly useful for some applications of the present invention. Polymers useable in the methods, devices and device components of the present invention include, but are not limited to, plastics, elastomers, thermoplastic elastomers, elastoplastics, thermostats, thermoplastics and acrylates. Exemplary polymers include, but are not limited to, acetal polymers, biodegradable polymers, cellulosic polymers, fluoropolymers, nylons, polyacrylonitrile polymers, polyamide-imide polymers, polyimides, polyarylates, polybenzimidazole, polybutylene, polycarbonate, polyesters, polyetherimide, polyethylene, polyethylene copolymers and modified polyethylenes, polyketones, poly(methyl methacrylate, polymethylpentene, polyphenylene oxides and polyphenylene sulfides, polyphthalamide, polypropylene, polyurethanes, styrenic resins, sulphone based resins, vinyl-based resins or any combinations of these.
“Elastomer” refers to a polymeric material which can be stretched or deformed and return to its original shape without substantial permanent deformation. Elastomers commonly undergo substantially elastic deformations. Exemplary elastomers useful in the present invention may comprise, polymers, copolymers, composite materials or mixtures of polymers and copolymers. Elastomers useful in the present invention may include, but are not limited to, thermoplastic elastomers, styrenic materials, olefinic materials, polyolefin, polyurethane thermoplastic elastomers, polyamides, synthetic rubbers, PDMS, polybutadiene, polyisobutylene, poly(styrene-butadiene-styrene), polyurethanes, polychloroprene and silicones.
Durometer is a standard measure of the hardness of a material. The durometer measurements reported herein a based on the Shore A scale: ASTM D2240 15-8. It is preferred that the polymeric material of the present invention has a Durometer Shore A value between about 15 and about 85. It is further preferred that the polymeric material of the present invention has a Durometer Shore A value between about 30 and about 70.
In the following description, numerous specific details of the devices, device components and methods of the present invention are set forth in order to provide a thorough explanation of the precise nature of the invention. It will be apparent, however, to those of skill in the art that the invention can be practiced without these specific details.
Polymeric composition 100 as shown in
Furthermore, while the embodiments of polymeric composition 100 shown in the several FIGs. are substantially uniform—there is little discernable variation from one “wave” of polymeric composition 100 to the next—substantial uniformity is not necessary. Rather, the uniformity of the waves of a polymeric composition 100 of the present invention reflects the mold in which the composition is formed.
Thus, the wave pattern of polymeric composition 100 incorporated into body part protector 1800 shown in
Suitable polymers for blending or mixing with olefin block copolymer, especially ethylene based block interpolymers used in the present invention include, but are not limited to, another olefin block copolymer, especially ethylene based block interpolymers, low density polyethylene, heterogeneously branched LLDPE, heterogeneously branched ULDPE, medium density polyethylene, high density polyethylene, grafted polyethylene (e.g. a maleic anhydride extrusion grafted heterogeneously branched linear low polyethylene or a maleic anhydride extrusion grafted (MAH-g) homogeneously branched ultra low density polyethylene), ethylene acrylic acid copolymer, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, polystyrene, polypropylene, polyester, polyurethane, polybutylene, polyamide, polycarbonate, rubbers, ethylene propylene polymers, ethylene styrene polymers, styrene block copolymers, and vulcanates.
It is preferred that the polymeric material of the present invention consist of polyurethane resins, silicone rubbers or polyvinyl chloride.
A number of different polymers may be used as the base component of adhesives in accordance with embodiments of the present invention, such as the olefin block copolymers, especially ethylene based block interpolymers. For example, ethylene vinyl acetate (EVA) based polymers may be used. The type and amount of wax and resin used with the EVA copolymer can control the set time and the residual tack of the adhesive. In some instances, filler may be added to EVA adhesives for special applications. Other embodiments of the present invention may use polyethylene-based polymers, polypropylene-based polymers, propylene-ethylene copolymers, amorphous poly alpha-olefins, polyamides, block copolymers, and/or other polymers known in the art. For example, ethylene ethyl acrylate (EEA), styrene-isoprene-styrene copolymers, styrene-butadiene-styrene copolymers, as well as a number of other styrene copolymers (SEBS, SEPS, etc.), polyurethane polyvinyl chloride, latex nitrile, acrylonitrile copolymers, acrylics (including pure acrylics as well as styrene acrylics and vinyl acrylics), and polyisobutylene may be used. In addition, polymers such as ethylene butyl acrylate (EnBA) and epoxydized polybutadiene (PBE) may be used. In preferred embodiments, synthetic polymers are used with embodiments of the present invention.
Again, this non-comprehensive list is just representative of the types of polymers that may be used in forming the dispersions and adhesive compositions in accordance with embodiments of the present invention. Those having ordinary skill in the art will recognize that a number of other suitable polymers exist.
Additionally, biocides that enhance biological stability may be used. Those having ordinary skill in the art will recognize that a number of suitable compounds exist. For example, chlorine, quaternary ammonium compounds, nano-particulate silver and sodium pentachlorophenate are all suitable examples. One particularly useful biocide is sold under the trademark DOWICIL 200, by The Dow Chemical Company (Midland, Mich.). Biocides may be present in a range from about 0 to about 1 weight percent of the total weight.
As used herein, the term “stretchable” refers to materials, structures, devices and device components capable of withstanding strain without fracturing or mechanical failure. Stretchable polymeric materials of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes.
Even when undergoing significant strain, such as strain greater or equal about 0.5%, preferably 1% and more preferably 2%. Stretchable polymeric materials of the present invention are flexible, bent and/or in a deformed states.
Exemplary polymeric materials of the present invention having curved internal surfaces useful in present invention comprise bent structures. In the context of this description, a “bent structure” refers to a structure having a curved conformation resulting from the application of a force. Bent structures in the present invention may have one or more folded regions, convex regions and/or concave regions. Bent structures useful in the present invention, for example, may be provided in a coiled conformation, a wrinkled conformation, a buckled conformation and/or a wavy (i.e., wave-shaped) configuration.
A flexible polymeric material of the present invention may be in a conformation wherein the bent structure is under strain. In some embodiments, the bent structure, such as a bent ribbon structure, is under a strain equal to or less than about 30%, a strain equal to or less than about 10% in embodiments preferred for some applications, a strain equal to or less than about 5% in embodiments preferred for some applications and a strain equal to or less than about 1% in embodiments preferred for some applications. In some embodiments, the bent structure, such as a bent ribbon structure, is under a strain selected from the range of about 0.5% to about 30%, preferably for some applications a strain selected from the range of about 0.5% to about 10%, preferably for some applications a strain selected from the range of about 0.5% to about 5%.
Surfaces of a flexible polymeric material of the present invention and, are provided in a bent structure, for example a bent structure having a coiled, wave-shaped, buckled and/or wrinkled conformation. The present invention includes embodiments wherein stretchable polymeric materials of the present invention are interconnected. Any conventional means of connecting polymeric materials may be used. For example, metal connectors (such as rivets, and nuts and bolts); leather (laces), sewing (thread) and adhesive connectors may be used.
The polymeric material of the present invention may have a coiled, wave-shaped, buckled and/or wrinkled configuration. In these embodiments, the bent structure enables these devices to exhibit good performance even when undergoing significant strain,
Bent structures and curved internal surfaces of polymeric material of the present invention may have any contour profile providing stretchability and/or flexibility including, but not limited to, contour profiles characterized by at least one convex region, at least one concave region or a combination of at least one convex region and at least one concave region. Contour profiles useful in the present invention include contour profiles varying in one or two spatial dimensions. Use of a bent structure having an internal surface with a contour profile exhibiting periodic or aperiodic variations in more than one spatial dimension are useful for providing stretchable crease pattern materials capable of stretching, compression, flexing or otherwise deformation in more than one direction, including orthogonal directions.
Useful embodiments include curved internal surfaces provided by bent polymeric material of the present invention having conformations comprising a plurality of convex and concave regions, for example an alternating pattern of convex and concave regions provided in a wave-shaped configuration. In an embodiment, the curved internal surface, or optionally the entire cross sectional component, of a stretchable and/or flexible polymeric material of the present invention has a contour profile characterized by a substantially periodic wave or, alternatively, a substantially aperiodic wave. In the context of this description, periodic waves may comprise any two or three dimensional wave form including but not limited to, one or more sine waves, square waves, Aries functions, Gaussian wave forms, Lorentzian wave forms, or any combination of these. In another embodiment, the curved internal surface, or optionally the entire cross sectional component, of a polymeric material of the present invention has a contour profile comprising a plurality of aperiodic buckles having relatively large amplitudes and widths. In another embodiment, the curved internal surface, or optionally the entire cross section component, of a polymeric material of the present invention has a contour profile comprising both a periodic wave and a plurality of aperiodic buckles.
In one embodiment, a stretchable polymeric material of the present invention comprises a bent structure, such as a bent ribbon structure, having a periodic or aperiodic wave-shaped conformation extending along at least a portion of its length, and optionally width. The invention includes, for example, bent structures, including bent ribbon structures, having a sine wave conformation with periodicities between about 200 microns to about 10 cm, and preferably for some applications periodicities between about 500 microns to about 2 cm. The invention includes, for example, bent structures, including bent ribbon structures, having a sine wave conformation with amplitudes between about 0.1 and about 20 mm and preferably for some applications amplitudes between about 0.5 and about 10 mm. Bent structures may be provided in other periodic wave form conformations such as square wave and/or Gaussian waves, extending along at least a portion of the lengths and/or widths of these structures. Stretchable and flexible polymeric material of the present invention comprising bent ribbon structures may be expandable, compressible, bendable and/or deformable along an axis extending along the length of the ribbon, such as an axis extending along the direction of a first wave form of the curved internal surface, and, optionally, may be expandable, compressible, bendable and/or deformable along one or more other axes, such as axes extending along the directions of other wave forms of the bent structures and curved internal surface.
In some embodiments, the conformation of crease pattern structures and electronic devices of this aspect of the present invention changes when mechanically stressed or when forces are applied. For example, the periodicities and/or amplitudes of bent crease pattern structures that have wave-shaped or buckled conformations may change in response to applied mechanical stress and/or forces. In some embodiments, this ability to change conformation provides for the ability of stretchable crease pattern structures to expand, compress, flex, deform and/or bend without experiencing significant mechanical damage, fracture.
In some embodiments, the wave-shaped, buckled and/or stretchable conformation provides a way to mechanically tune useful the properties of compositions, materials and devices of the present invention. For example, the mobility of a crease pattern structure, depend, at least in part, on strain. Spatially varying strain in the present invention is useful for modulating the materials and device properties in useful ways. As another example, spatially varying strain in a waveguide causes spatially varying index properties (through the elasto-optic effect), which can also be used to advantage for different types of grating couplers.
The physical dimensions and composition of the crease pattern structure at least in part influences the overall mechanical of the stretchable crease pattern elements of the present invention. Useful flexible substrates included, but are not limited to, flexible substrates having a component wall thickness selected over the range of about 0.1 millimeter to about 100 microns. In a useful embodiment, the flexible substrate comprises a poly(dimethylsiloxane) PDMS layer and has a component wall thickness selected over the range of about 0.1 millimeters to about 10 millimeters, preferably for some applications a component wall thickness selected over the range of about 1 millimeters to about 5 millimeters.
The composition and physical dimension of the supporting flexible substrate may also influence, at least in part, the overall mechanical properties of stretchable crease pattern structure of the present invention.
In some embodiments of this aspect of the invention, the prestrained elastic substrate is expanded along a first axis, and optionally along a second axis orthogonally positioned relative to the first axis.
To get better anti-reflection result, we can do further processing on this wavy surface, such as make surface roughness much smaller than wavelength of wavy crease pattern structure, for example. In short, the partially- or fully-processed wavy/bent crease pattern structures can be transferred onto other substrate (not limited to Polydimethylsiloxane (“PDMS”), and can be used with more enhanced performance, by adding further processing if necessary.
In one embodiment, a prepolymer, such as a PDMS pre-polymer, is cast and cured on the stretchable crease pattern structure. Such a polymer (e.g. 2D ultrathin polymer) or an inorganic (e.g. SiO2) is a preferred embodiment.
The prepolymer, or polymer reaction mixture, is put into a mold 400 for the curing process. Typically, mold 400 is a two part mold having a first part 410, that when mold 400 is assembled, projects into second mold part 420.
After mold 400 has been injected with a volume of reaction mixture sufficient to substantially fill mold 400, mold 400 is placed upright in a pressure vessel.
Methods of prestraining elastic substrates useful for the present methods include bending, rolling, flexing, and expanding the elastic substrate prior to and/or during contact and bonding with the crease pattern structure, for example by using a mechanical stage. A particularly useful means of prestraining the elastic substrates in more than one direction comprises thermally expanding the elastic substrate by raising the temperature of the elastic substrate prior and/or during contact and bonding with the crease pattern structure. Relaxation of the elastic substrate is achieved in these embodiments by lowering the temperature of the elastic substrate after contact and/or bonding with the transferable, and optionally printable, printable crease pattern structure. In some methods, the elastic substrate is prestrained by introducing a strain of about 1% to about 30%, and preferably for some applications by introducing a strain of about 3% to about 15%.
In the context of this description, the expression “elastic substrate” refers to a substrate (or structure) which can be stretched or deformed and return, at least partially, to its original shape without substantial permanent deformation. Elastic substrates commonly undergo substantially elastic deformations. Exemplary elastic substrates useful in the present include, but are not limited to, elastomers and composite materials or mixtures of elastomers, and polymers and copolymers exhibiting elasticity. In some methods, the elastic substrate is prestrained via a mechanism providing for expansion of the elastic substrate along one or more principle axes. For example, prestraining may be provided by expanding the elastic substrate along a first axes. The present invention also includes, however, methods wherein the elastic substrate is expanded along a plurality of axes, for example via expansion along first and second axis orthogonally positioned relative to each other. Means of prestraining elastic substrates via mechanisms providing expansion of the elastic substrate useful for the present methods include bending, rolling, flexing, flattening, expanding or otherwise deforming the elastic substrate. The present invention also includes means wherein prestraining is provided by raising the temperature of the elastic substrate, thereby providing for thermal expansion of the elastic substrate.
A water clear, 65 Shore A polyurethane elastomer polymerization reaction mixture was prepared by blending substantially equal volumes of BJB Enterprises WC-565 Parts A and B at ambient temperature.
The label on the BJB Enterprises WC-565 Part A package identifies its components as:
The label on the BJB Enterprises WC-565 Part B package identifies its components as:
About 300 oz of the above Example 1 combined reaction mixture was injected into a crease pattern mold, at about 70° F. The exterior of the mold was about 10 inches long, about 8 inches wide and about 1 inch high. The mold with the injected reaction mixture was placed in a pressurized container at a pressure between about 70 and 80 psig of air for about 18 hours. Thereafter, the material was removed from the mold.
A high tear strength, 60 Shore A polyurethane elastomer polymerization reaction mixture was prepared by blending about 100 parts, by volume of BJB Enterprises ST-1060 Part A with about 58 parts by volume of BJB Enterprises ST-1060 Part B at ambient temperature.
The label on the BJB Enterprises ST-1060 Part A package identifies its components as:
The label on the BJB Enterprises ST-1060 Part B package identifies its components as:
About 300 oz of the above Example 2 combined reaction mixture was injected into a crease pattern mold, at 70° F. The exterior of the mold was about 10 inches long, about 8 inches wide and about 1 inch high. The mold with the injected reaction mixture was placed in a pressurized container at a pressure between about 70 and 80 psig of air for about 18 hours. Thereafter, the material was removed from the mold.
A translucent silicone rubber polymerization reaction mixture was prepared by blending about 100 parts, by weight of BJB Enterprises TC-5040 Part A with about 10 parts by weight of BJB Enterprises TC-5040 Part B at ambient temperature.
The label on the BJB Enterprises TC-5040 Part A package identifies its components as:
The label on the BJB Enterprises TC-5040 Part B package identifies its components as:
About 300 oz of the above Example 3 combined reaction mixture was injected into a crease pattern mold, at 70° F. The exterior of the mold was about 10 inches long, about 8 inches wide and about 1 inch high. The mold with the injected reaction mixture was placed in a pressurized container at a pressure between about 70 and 80 psig of air for about 18 hours. Thereafter, the material was removed from the mold.
As shown in the cut-away view of
The body part protector 1800 of the present invention provides protection to a body part by adsorbing energy—e.g., a blow—applied to the body part protected. The crease pattern polymeric composition 100 temporarily deforms and thereby adsorbs the applied energy.
In the embodiment of an expandable container 2100 shown in
In yet a further embodiment, it is envisioned that an additional piece of material is secured to one of the two pieces of polymeric composition 100 in such a position that the material can be used to cover the opening of the expandable container. In such embodiments, the piece of polymeric composition 100 that the material is not secured to has a means of temporarily being attached to the material to close the opening of the expandable container. For instance, the material and the second polymeric composition may have a button and a button hole; a hook and a loop; a sipper; or a latch.
Moreover, in some embodiments of the expandable container having material for covering the opening of the expandable container, the material that covers the opening is also a piece of polymeric composition 100.
In a still further embodiment of the present invention, a tarp is made of a polymeric material with a crease pattern. In a preferred tarp embodiment of the present invention, the polymeric material with a crease pattern has a component wall thickness of between about 1.5 and 5 mm. It is more preferred that the component wall thickness of the tarp embodiment is between about 2 and 3 mm.
Also in the tarp embodiment, it is preferred that the distance from the trough to the crest of a majority of the waves of the crease pattern is between about 10 and 25 cm. It is further preferred that the distance from the trough to the crest of a majority of the waves of the crease pattern is between about 15 and 20 cm.
In a particularly preferred tarp embodiment of the present invention, there are a plurality of grommets along at least one edge of the polymeric material. It is preferred that each of the grommets is within about 10 cm of an edge of the polymeric material. These grommets may be in the mold when the reaction mixture is added or they may be added to the polymeric material after it has cured. Desirably the diameter of the grommets is between about 5 and 15 mm. It is further desired that the diameter of the grommets is between about 8 and 18 mm. It is further desired that the grommets are along at least two edges of the polymeric material, and it is still further desired that the edges with grommets do not intersect.
While each of the tiles 2420 shown in
Similar to the tiles 2420 shown in
The methods of the present invention are capable of fabricating crease pattern elements, devices and device components from elastomeric materials. Allowing the crease pattern elements to relax, at least partially, results in formation of stretchable structures having curved internal surfaces, for example structures that have a wave-shaped and/or buckled contour profile. This aspect of the present invention includes stretchable structures that have a bent structure, such as internal, and optionally external, surfaces provided in a coiled conformation, in a wrinkled conformation, buckled conformation and/or in a wave-shaped configuration.
Flexible substrates useful in stretchable crease pattern components of the present invention include, but are not limited to, polymer substrates and/or plastic substrates.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US15/27706 | 4/27/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61984972 | Apr 2014 | US | |
| 62007070 | Jun 2014 | US |
