NovaCentrix® Awarded U.S. Patent Critical for Sintering Metal Inks on Low Temperature Substrates

NovaCentrix, a leader in printed electronics manufacturing technologies were recently granted an U.S. Patent 7,820,097 entitled “Electrical, Plating and Catalytic Uses of Metal Nanomaterial Compositions”.  This covers in part the use of flash lamps to sinter metal-based inks and materials on low-temperature substrates such as paper and plastic and includes high-speed and roll-to-roll processing.  This process is critical to the advancement of innovative new products in photovoltaics, displays, RFID, sensors, batteries, capacitors, and smart packaging.

“One of the most exciting aspects of this technology is its scalability and economy.  Inexpensive flexible substrates can now be used.  Furthermore, processing can be performed at hundreds of feet per minute in a roll-to-roll environment,” said Dr. Kurt Schroder, Chief Scientist and lead patent author.  “In addition to processing silver, gold, and nickel used in conductive inks, the high speed process can sinter easily-oxidized particles such as copper in an ambient air environment, thus eliminating the need for a reduction furnace or inert atmosphere.  This room-temperature process enables truly inexpensive conductive traces for printed electronics.”

The claims are shown below and I have included the full set as they illustrate how the main broad claim 1 has been defined and the dependant claims used to expand on the materials, the substrate and the manner in which the printing process can be accomplished.

1. A method for sintering materials comprising: depositing a material on a substrate, wherein said substrate has a decomposition temperature below 450 degrees Celsius, wherein said material has at least one dimension less than 1 micrometer, wherein said material includes at least one metal; and irradiating said material on said substrate in ambient air by a flash lamp for sintering said material on said substrate, for a duration between one microsecond and one hundred milliseconds such that the conductivity of said material on said substrate increases by at least two-fold.
2. The method of claim 1, wherein said at least one metal is copper.
3. The method of claim 1, wherein said material is included within an ink formulation.
4. The method of claim 1, wherein said substrate comprises a substance selected from the group consisting of PET, polyester, polymers, resins, paper products, organic compounds, laminates, and combinations thereof.
5. The method of claim 1, wherein said depositing includes producing a film or pattern on said substrate from said material included within an ink formulation.
6. The method of claim 1, wherein said depositing further includes printing.
7. The method of claim 6, wherein said printing is selected from the group consisting of screen printing, inkjet printing, gravure, laser printing, xerographic printing, pad printing, painting, dip pen, syringe, airbrush, lithography, flexography and combinations thereof.
8. The method of claim 1, wherein said method further includes moving said substrate when said material is being irradiated by said flash lamp.
9. The method of claim 8, wherein said substrate is being moved continuously.
10. The method of claim 8, wherein said substrate is dispensed from a roll.

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Carbon Nanotube patent granted for Canatu Ltd

Canatu Ltd (Finland) has been in the news recently after receiving an investment of €4.7 M to fund its production development.  I was particularly interested to see whether they had been granted any patents from their portfolio of applications on carbon nanotubes and what new applications have emerged.

Background on Canatu:

Founded in 2004, Canatu is a spin-off from the Helsinki University of Technology (now Aalto University). Canatu’s business is the production and sales of a new class of versatile nanomaterial based films and components.

Canatu has developed a novel form of carbon, namely NanoBuds™, and a new way to directly produce high value components on any substrate from this material by Direct Dry Printing™. These components improve the performance and reduce the cost of optical and electrical devices and diminish their environmental footprint. Canatu is currently developing its flexible thin film NanoBud™ components and production processes to supply display, touch, photovoltaic, tracking and haptic customers in the optics, energy and electronics sectors.

Granted Patent:

The NanoBud™ technology (a molecule having a fullerene molecule covalently bonded to the side of a carbon nanotube) is described in the granted patent EP1948562B1.

This patent was granted with the main claim reading:

Claim 1. A fullerene functionalized carbon nanotube, comprising one or more fullerenes and/or fullerene based molecules bonded to the carbon nanotube, characterised in that the bond between said fullerenes and/or fullerene based molecules and said carbon nanotube is covalent and is formed on the outer surface wall and/or inner surface wall of said carbon nanotube.

Further details are claimed around the size of the fullerene and how it is covalently bonded.  The CNT can be a single, double or multi-walled nanotube and can be formulated as a solid, liquid, gas or paste, deposited or synthesized on a surface.

There is also claimed a method for its manufacture:

Claim 9. A method for producing at least one fullerene functionalized carbon nanotube comprising at least one fullerene and/or a fullerene based molecule covalently bonded to the outer surface and/or inner surface of said at least one carbon nanotube,characterised in that the method comprises: providing at least one catalyst particle to a reactor heated to between 250 and 2500 °C; providing a gas flow to said reactor wherein the gas comprises at least one carbon source; providing at least two reagents including CO2 and H2O, or precursors thereof to obtain the concentration of H2O between 45 and 245 ppm and the concentration of CO2 between 2000 and 6000 ppm. releasing carbon from the carbon source into or onto one or more catalyst particles in the presence of the reagents; and collecting said at least one fullerene functionalized carbon nanotube comprising at least one fullerene and/or a fullerene based molecule covalently bonded to a wall of said at least one carbon nanotube.

The additional method claims include details around the catalyst (very broad) and the reagents (can be an etching agent) and the carbon source.  Finally the last three claims relate to the way the material is used to create a functional device.

21. A functional material, wherein the function of the material is at least one of field emission, light emission, electric conduction, thermal conduction, fuel cell, battery, metal-matrix composite, polymer-matrix composite, capacitor, electrode, transistor, diode, drug molecule carrier characterised in that it comprises at least one fullerene functionalized carbon nanotube according to any one of claims 1 to 8.

22. A thick or thin film, a line, a wire or a layered or three dimensional structure, characterised in that it comprises one or more fullerene functionalized carbon nanotubes according to any one of claims 1 to 8.

23. Using one or more fullerene functionalized carbon nanotubes in accordance to any one of claims 1 to 8 in preparation of a device.

Fujifilm files patent for flexible solar cell technology

Fujifilm used to be a major competitor when I was involved in photographic film and plate manufacture for Kodak.  It is interesting to see that they have converted their expertise in these areas to the fabrication of flexible Aluminium based films for solar cell technology.  In a recent announcement Fujifilm Corp announced they have formed a CIGS photovoltaic (PV) cell on an aluminum flexible substrate and achieved a conversion efficiency of 17.6% with an aperture area of 0.486cm2.  Also, they confirmed a conversion efficiency of 12.5% with an aperture area of 72cm2.

Interestingly a US patent application (US20100224249) appeared just a few days ago covering this technology.  Fujifilm used anodic oxidation to form an aluminium oxide (Al2O3) layer on an aluminium foil as the substrate which is treated with a diffusion barrier layer of either titanium or chromium. On the substrate, a molybdenum (Mo) layer, CIGS layer, cadmium sulfide (CdS) layer and zinc oxide (ZnO) layer are stacked. Furthermore, sodium doping is used to increase conversion efficiency.  Full details can be found in their concrete examples 1 and 2.  A comparison with an example not containing the diffusion barrier layer had a lower conversion efficiency.

New patent for Kent Displays Inc. – Flexible LCD Manufacturing Process

Background on Kent Displays

Founded in 1993 as the result of a joint venture between Kent State University (Ohio) and Manning Ventures (Rochester NY), Kent Displays is a world leader in the research, development and manufacture of Reflex™ No Power LCDs for unique, sustainable applications including electronic skins, writing tablets, smartcards and eReaders. The technology is based upon bistable cholesteric LCD technology.

In October 2008, Kent Displays installed a new roll-to-roll production line in their headquarters in Kent, Ohio, U.S.A. to mass produce Reflex LCDs from rolls of plastic. The line is the first of its kind in the world and produces no waste water/chemicals and less solvent emissions than sheet-based processes. The flexibility, durability and exceptional thinness of the plastic displays, combined with no power image retention and superior optical characteristics, result in a versatile, environmentally-friendly alternative to traditional paper and backlit LCDs – with nearly endless applications!

New Patent Granted on 10th Aug 2010:

US7773064B2 was granted on 10th Aug 2010 and describes a novel concept in liquid crystal display technology: a display that is a manufactured film. The invention is a display film that is fabricated, lifted off a release liner and then transferred to any desired substrate. The display film may be fabricated by applying a plurality of layers in sequence to include all display components or can be fabricated with some components and later laminated together to complete the display device.

A particular feature of this technology is that it does not need to be made on a transparent substrate making available a broader range of substrate materials such as fabrics that can be deformed by bending, rolling, draping or folding.

There are 58 claims in total covering many different forms of the basic concept described in claim 1.  These include laminating onto a solar panel for a self powered display; laminating onto fabrics; a multilayer film with sublayers of reflective red, green and blue for colour displays.

The first claim is reproduced below:

1. A transfer display film comprised of stacked layers that are prepared on, cured or dried and lifted from a release surface and then transferred to a substrate, wherein said stacked layers comprise at least one liquid crystal dispersion layer comprising liquid crystal material dispersed in polymer, a first electrically conductive layer located near one side of said dispersion layer, a second electrically conductive layer located near the other side of said dispersion layer and an electrical insulation layer located between and in contact with said dispersion layer and said first or second conductive layer.

E-ink has new patent granted on electrophoretic displays with dyes.

US7746544 was granted on 29 June 2010 and looks to be a great reference patent describing novel electrophoretic displays and materials useful in making such displays.  The invention particularly relates to electro-osmotic displays and in particular to those where the encapsulated liquids used in the display contain a dye.  The original application contained 9 claims but in the granted patent only three amended claims were allowed.  These are shown below:

1. An encapsulated electrophoretic display, comprising a capsule containing at least two immiscible fluids, each fluid having a different refractive index such that the fluids create a first optical effect, wherein at least one of the fluids within the capsule moves to create a second optical effect in response to an electric field, and wherein at least one of the fluids contains a dye.

2. The display of claim 1, wherein a planar index mismatch results from the motion of the fluids in the capsule.

3. The display of claim 1, wherein a non-planar index mismatch results from the motion of the fluids in the capsule.

The E-ink website has some good technical overviews of how EPDs work and the reader can view these by clicking here.  Their website does not yet explain the basics of a colour version but the patent describes how a multi-colour display can be made through the use of cyan magenta and yellow particles in the dispersion recreating a full colour display in the way a printed page is produced.  Here is the extract from the patent:

As an example of a multi-color, encapsulated electrophoretic display, there may be magenta particles with an average zeta potential of 100 mV, cyan particles with an average zeta potential of 60 mV, and yellow particles with an average zeta potential of 20 mV. To address this display to the magenta state, all the particles are pulled to the back of the cell by applying an electric field in one direction. Subsequently, the field is reversed for just long enough for the magenta particles to move to the top face of the display cell. The cyan and yellow particles will also move in this reversed field, but they will not move as quickly as the magenta particles, and thus will be obscured by the magenta particles.

To address the display to the cyan state, all the particles are pulled to the back of the cell by applying an electric field in one direction. Then the field is reversed for just long enough for the magenta and cyan particles to move to the top face of the display cell. The field is then reversed again and the magenta particles, moving faster than the cyan particles, leave the cyan particles exposed at the top of the display.

Finally, to achieve a yellow display, all the particles are pulled to the front of the display. The field is then reversed and the yellow particles, lagging behind the magenta and cyan particles are exposed at the front of the display.

Apple files new patent application for touch screen with feedback

Apple has brought many innovative features to the way we interact with and use touch screens and continuing their development of the touch screen interface a new patent application has just published for a touch screen that also has a buzzing or tingling feedback built in that works together with the touch sensitive mechanism to take the user experience to new levels.  While this is not strictly a printed electronics approach this is exactly the sort of thing that printed/plastic  electronics manufacturing methods might be applied to.

US20100156818 was filed on 6 April 2009 and published on 24 June 2010.  The inventors are Bobby Burrough and Benjamin Pope.  The application describes how the haptic feedback that can be generated by producing sensations from haptic actuators ( e.g. piezoelectric materials) that are felt by the fingers as they move over the screen.  Some simple examples are described such as varying the sensation felt as the fingers are moved closer or further apart in the pinch movements that enable zooming of the display.  I would imagine that the variations on effects that can be produced are endless and many applications will be developed to make use of this feature once the system is available.

An illustration of the mechanism from the patent application is shown here:

The first claim is:

An apparatus providing multi-touch haptic feedback, comprising a touch pad having a touch sensitive surface arranged to receive a user provided multi-touch event associated with at least two different locations on the touch sensitive surface; a multi-touch detection mechanism operatively coupled to the touch sensitive surface that detects the multi-touch event and generates a corresponding a multi-touch signal; and a plurality of haptic feedback devices operatively coupled to the multi-touch detection mechanism and the touch sensitive surface cooperatively arranged to concurrently provide tactile feedback at each of the at least two different locations on the touch sensitive surface in response to the multi-touch signal.

New Patents granted for Pixtronix – MEMS based light modulation

Two US patents were granted today to Pixtronix for their Digital MEMS shutters designed to replace liquid crystals to deliver low power, high speed light modulation for an innovative display technology.  US7742215 and US7742016 describe the technology used to provide the methods and apparatus for forming images on a projection display utilizing a control matrix to control the movement of MEMs-based light modulators.

This technology was first demonstrated as an alternative to the liquid crystal display, Pixtronix’s display uses a backlight, but unlike most LCDs it also reflects ambient light, allowing for an easier-to-read monochrome e-reader mode. The pixels in the display are made of tiny silicon shutters: micro-electromechanical systems (MEMS) that open and close to emit red, blue, and green light in rapid sequence, creating the illusion of a range of colors.  These patents extend protection for the technology into the projector market.

Further details of the technology can be found on their website http://www.pixtronix.com/technology/index.asp and a white paper is available for download.

For those of you that like to see the first claim here it is:

1. A projection display comprising: a transparent substrate; a plurality of shutter-based MEMS light modulators disposed on a surface of the transparent substrate, wherein the shutter-based light modulators each include an actuator for driving a shutter, wherein the actuators include first and second compliant beams, which, in response to application of a voltage across the first and second compliant beams, deform towards one another; and projection optics for projecting light modulated by the shutter-based MEMS light modulators onto a display surface to form an image.