Optical: systems and elements – Optical modulator – Light wave temporal modulation
Reexamination Certificate
2002-06-25
2004-06-08
Schwartz, Jordan M. (Department: 2873)
Optical: systems and elements
Optical modulator
Light wave temporal modulation
C359S273000, C359S321000, C252S583000
Reexamination Certificate
active
06747780
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to electrochromic (EC) materials that exhibit different colors as a function of an applied voltage, and more specifically, to apparatus utilizing specific organic polymer based EC materials, and methods of producing the specific organic polymer based EC materials.
BACKGROUND OF THE INVENTION
Electrochromic (EC) materials are a subset of the family of chromogenic materials, which includes photochromic materials, and thermochromic materials. These are materials that change their tinting level or opacity when exposed to light (photochromic), heat (thermochromic) or electricity (electrochromic). Chromogenic materials have attracted widespread interest in applications relating to the transmission of light.
An early application for chromogenic materials was in sunglasses or prescription eyeglasses that darken when exposed to the sun. Such photochromic materials were first developed by Coming in the late 1960s. Since that time, it has been recognized that chromogenic materials could potentially be used to produce window glass that can vary the amount of light transmitted, although the use of such materials is clearly not limited to that prospective application. Indeed, EC technology is already employed in the displays of digital watches.
With respect to window glass, EC materials are exciting because they require relatively little power to produce a change in their tinting level or opacity. EC windows have been suggested for use in controlling the amount of daylight and solar heat gain through the windows of buildings and vehicles. Early research indicates that EC window technology can save substantial amounts of energy in buildings, and EC glazings may eventually replace traditional solar control technology such as tints, reflective films, and shading devices (e.g., awnings). Because of their ability to control lighting levels and solar heat gain, EC windows have the potential of reducing the annual U.S. energy consumption by several quadrillion (10
15
) BTUs, or quads, which is a substantial decrease relative to current consumption rates.
Several different distinct types of EC materials are known. The primary three types are inorganic thin films, organic polymer films, and organic solutions. For many applications, the use of a liquid material is inconvenient, and as a result, inorganic thin films and organic polymer films appear to be more industrially applicable.
To make an EC device that exhibits different opacities in response to a voltage, a multilayer assembly is required. In general, the two outside layers of the assembly are transparent electronic conductors. Within the outside layers is a counter-electrode layer and an EC layer, between which is disposed an ion conductor layer. When a low voltage is applied across the outer conductors, ions moving from the counter-electrode to the EC layer cause the assembly to change color. Reversing the voltage moves ions from the EC layer back to the counter-electrode layer, restoring the device to its previous state. Of course, all of the layers are preferably transparent to visible light. Both inorganic and organic ion conductive layers are known.
In order to be useful in a window application, or in a display application, EC materials must exhibit long-term stability, rapid redox switching, and exhibit large changes in opacity with changes of state. For inorganic thin film based EC devices, the EC layer is typically tungsten oxide (WO
3
). U.S. Pat. Nos. 5,598,293, 6,005,705, and 6,136,161 each describe an inorganic thin film EC device based on a tungsten oxide EC layer. Other inorganic EC materials, such as molybdenum oxide, are also known. While many inorganic materials have been used as EC materials, difficulties in processing and slow response time associated with many inorganic EC materials have created the need for different types of EC materials.
Conjugated, redox-active polymers represent one different type of EC material. These polymers (cathodic or anodic polymers) are inherently electrochromic and can be switched electrochemically or chemically between different color states. A family of redox-active copolymers are described in U.S. Pat. No. 5,883,220. Another family of nitrogen based hetrocyclic organic EC materials is described in U.S. Pat. No. 6,197,923. Research into still other types of organic film EC materials continues, in hopes of identifying or developing EC materials that will be useful in EC windows.
While EC windows, or smart windows as they are sometimes called, are expected to represent a significant commercial application of EC technology, one additional potential use of an EC is in producing displays, sometimes referred to smart displays, or digital windows (DWs). One promising application for DW systems relates to deoxyribonucleic acid (DNA) chip reading. For more efficient DNA chip reading/writing technology, it would be desirable to replace expensive custom photomasks in the photosynthesizing of oligonucleotides in DNA array fabrication. There are several reasons why it would be desirable to develop a new method applicable to this technology for use in oligonucleotide chip manufacturing. Specifically, oligonucleotide chips have become increasingly important, as more genomes of organisms are sequenced. Accordingly, there is a need to develop a low cost, easy to use, high-density DNA arranger and system for reading unknown DNAs, based on surface plasmon resonance, with higher lateral resolution that is provided in current systems.
A suitable system for such an application should employ a switchable window that is readily changed from transparent to nontransparent (e.g., to dark blue) by varying an electric potential polarity (anodic EC polymer sides have a negative polarity and a positive polarity, respectively). These switchable window laminate materials should be convertible to a digital (pixel) array having a size typically ranging from about submicron to about 50 microns, and each array unit should be independently controlled to change from a transparent to a nontransparent state. By combining this functionality with an surface plasmon resonance (SPR) system serving as a real time analyzer of unknown molecules, including DNA sequences and characterizations of unknown molecules and in vivo and in vitro cell-cell interactions. Such a high resolution SPR system should then be useful for analyzing unknown molecules and DNA sequences on a real-time basis, at faster speed than is currently possible, by scanning through one group of molecules after another, i.e., by opening the corresponding digital window (DW) unit. With such a system, the speed with which unknown molecules (and DNA and RNA sequences) can be analyzed will be much enhanced, compared with conventional prior art techniques.
An additional exciting application of EC technology relates to the use of EC devices for display technologies, beyond the somewhat limited application of monochromatic displays now used in digital watches. EC devices that can controllably transition between more than two color states offer the potential of flat panel multicolor displays, using the digital pixel array noted above.
SUMMARY OF THE INVENTION
A first aspect of the present invention is directed to a method for synthesizing EC polymers and counter-electrodes having properties that can be beneficially employed in EC polymer devices. A second aspect of the present invention is directed to specific configurations of EC polymer based devices, while a third aspect is directed to specific applications of EC polymer devices. With respect to synthesizing EC polymers and counter-electrodes, two embodiments of the method for synthesizing EC polymers is disclosed, as well as two embodiments for fabricating counter-electrodes for use in EC devices.
The first synthesis method is directed toward the production of poly[3,3-dimethyl-3,4-dihydro-2H-thieno[3,4-b][
1,4]dioxepine], also known as PProDOT-Me
2
. Preferably, equivalent molar amounts of 3,4-dimethoxythiophene and 2,2-dimethyl-1,3-
Taya Minoru
Xu Chunye
Anderson Ronald M.
Schwartz Jordan M.
Stultz Jessica T
University of Washington
LandOfFree
Electrochromic organic polymer synthesis and devices... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrochromic organic polymer synthesis and devices..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrochromic organic polymer synthesis and devices... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3364044