All about Flexible Macroelectronics

Vitex Systems accelerates permeation barrier production for photovoltaics

2009-09-22T12:27:00.002-04:00

Vitex Systems, Inc., a leading technology developer, licensor and engineering service provider for thin-film encapsulation and moisture barrier films, today announced that it has expanded its leading edge thin-film barrier capability with the qualification of its new state of the art, 2nd generation deposition equipment. The new equipment will be located in Vitex’s facility in San Jose and will allow the company to further enhance its moisture barrier film technology as well as service its customers.

In conjunction with its internal expansion efforts, Vitex has also elected to join the Flexible Display Center located at Arizona State University (ASU) and to donate its previous generation tool to the Center. The Flexible Display Center at ASU, which was established by the U.S. Army in February 2004, boasts collaborations with university, government and industry partners, both national and international.

“We have many potential customers asking Vitex to provide Barix Encapsulation and Barix Barrier Film for various applications. The investment for the new deposition equipment provided by funding from Battelle will not only expand our developmental capabilities but will also allow Vitex to more effectively service many new customers,” said Chyi-Shan Suen, President and COO at Vitex Systems. “In addition, all other member companies will have access to test and evaluate our barrier with our tool in the Center. We very much look forward to participation in this outstanding organization.”

Over the past year, Vitex has made excellent progress demonstrating the unique capabilities of its Barix Barrier Film for encapsulation of thin-film photovoltaic cells. Cooperating with Pacific Northwest National Laboratory, Vitex recently demonstrated results obtained on SoloPower’s thin-film CIGS PV that, when protected by Vitex’s Barix Barrier Film, the cells had less than 10% efficiency degradation after 1920 hours of damp heat tests at 85 degrees and 85% relative humidity, while the IEC 61646 standard only demands testing to 1000 hours.

(Source: Vitex press release)

OLEDs: types and applications - white OLEDs

2009-03-16T18:24:00.006-04:00

This is the fifth post of the Macroelectronics.org OLEDs series. Stay tuned.

White OLED is possibly the future generation of lighting source. A typical incandescent light bulb is roughly 12 lm/watt. (Lumen or lm is the unit describing the perceived power of light. Therefore, lumens/watt tells us how bright the light is generated per one watt.) The energy efficiency of conventional incandescent light bulbs is only about 4%. That is, for every 100 units of energy input to a light bulb, 96 units of energy are lost mostly in a form of heat. On the other hand, a fluorescent light, even with a much better efficiency up to 92 lm/W, poses an environmental problem due to the fact that it contains mercury which is hard to dispose and is harmful to an environment. The light produced is not an incandescent light; thus making it uncomfortable to human’s eyes. In addition, two types of these light bulbs are constrained by certain shapes. For example, fluorescent light always have to be shaped as a long tube. OLED lighting provides solutions to these problems.

OLED lighting uses the same technology as most OLED displays except that it only produces white light. Currently, the efficiency of white OLED is 102 lm/watt with a potential to reach up to more than 150 lm/watt according to Universal Display cooperation. Not only that, this OLED lighting is a thin sheet and does not have to be conformed into any specific shape. Imagine a wallpaper of paper-like light bulb. Because OLED composes mostly organic materials, it does not cause any environmental problem. The main setbacks with white OLED are that it can be easily damaged by water and the manufacturing cost is still too high to become a mass production. In year 2000, The U.S. Department of Energy established the solid-state lighting program which helps funding researches related to new generation of lighting. Universal Display, Philip, GE, and many other companies including government agencies are trying to push this OLED lighting technology forward, making the future of “greener light bulb” several steps closer to our home.

( via Universal Display, HowStuffWorks, General Electric(GE); image credit:GE )

OLEDS: types and applications - FOLED

2009-02-12T22:53:00.006-05:00

This is the fifth post of the Macroelectronics.org OLEDs series. Stay tuned.

Flexible OLED or FOLED is a very promising technology in the future. For FOLED to be flexible, metallic foils or thin plastics such as PET and PEN polyester films are used as the main substrate since it can endure strains very well. Because the display is flexible, it is less likely for the display to crack or break. Therefore, electronic products will last longer. Roll-to-roll process (found in printing industries) is an applicable manufacturing process, which will lower overall product costs. However, there are still many challenges before FOLED technology can be mass produced to the public. For instance, packaging FOLED is different than typical OLED. In order for typical OLED to be water resistance, two plates of thin glasses are sandwiched between the OLED. However, glass is brittle and it can not be used for FOLED where flexibility of the display is the key.

FOLEDs offer a new generation of display technology because they are durable, light weight, thin, flexible and cost effective. These qualities are ideal for mobile gadgets like cell phone, GPS, or even “smart clothing” where electronics are embedded within. Currently, companies such as Sony, Universal Display, Samsung, and US Army, are researching to make FOLED a feasible technology for everyday uses.

(via Universal Display, HowStuffWorks, and OLED-info ; video credit: Universal Display)

OLEDS: types and applications - AMOLED

2009-01-17T10:55:00.007-05:00

This is the forth post of the Macroelectronics.org OLEDs series. Stay tuned.

AMOLED, or active matrix OLED, is composed of an anode, a cathode, an organic layer, and a thin film transistor (TFT) matrix. Each pixel of the OLED is integrated onto a TFT array. TFT array controls the amount of current flows on each pixel which determines the brightness of generated light.

Instead of having external circuit to turn on/off the cathode and anode stripes that activate pixels in passive matrix configuration, AMOLED allows the current to flow through all of the OLED pixels while having TFTs controls how much current will each pixel gets. This is one of the advantages of AMOLED over PMOLED because TFT arrays need less power than external circuit. In addition, AMOLED’s pixel turns on and off at an incredibly rapid rate making it ideals for motion pictures. Though, AMOLED’s main disadvantage is its expensive manufacturing cost due to the intricacy of the active matrix structure that requires complex processes to fabricate.

Many leading display companies today such as Samsung, LG, Sony, Universal Display, Nokia and Kodak see a potential of and working on developing AMOLED displays. AMOLED now has become a promising technology for large display and portable display products.

(via universal display, howstuffworks, wikipedia, and oled-display ; image credit: howstuffworks and oled-display)

Applications of RFIDs (Part 1 of 3)

2009-01-16T20:30:00.007-05:00

RFIDs, as mentioned before, come in several different forms, each with its own advantages and disadvantages. Passive RFIDs do not have their own power supplies, but are limited to short range communications with the reader; Active RFIDs have longer ranges, but are more susceptible to interference.

Currently, in everyday use, we use RFIDs for theft prevention at stores. However, several companies have come up with several novel ideas to make lives easier.

Such a company is Metro Group. Innovating from the warehouse to one's home, their concept of the RFID is prevalent throughout everyday life from when one reaches for the milk in the refrigerator to sorting clothes for the laundry machine.

Metro Group is one of several companies making the RFIDs that are placed in warehouses to account for inventory. They also have concept designs for refrigerators that tell the owner if he or she is out of milk; laundry machines that can detect when you've mixed in a red sock with your white laundry; mirrors that can take a snapshot of your physique so that you can try on the clothes that you picked out without actually having to wear them; and personal pads that you can carry around in a store, which document which items you are about to purchase. The last allows the shopper to pass through a scanner, with credit card in hand and, with the items already listed, payment is all but a swipe away.

All of these items mentioned, from the red sock to the milk to the new outfit, are all fitted with RFIDs, which originate from the warehouse with the original shipments. These RFIDs are integrated into our everyday lives so that you do not have to worry about minute things of everyday life.

(via Metro Group; Photo Credit: Space is Lost)

OLEDs: types and applications - PMOLED

2009-01-05T03:35:00.006-05:00

This is the third post of the Macroelectronics.org OLEDs series. Stay tuned.

The Passive-Matrix OLED or PMOLED is the first OLED to be commercialized. PMOLED is composed of anode strips, cathode strips, an organic active layer, and a substrate. Passive matrix is the configuration in which anode and cathode strips are arranged perpendicularly having an organic active layer in between. The intersections between anode and cathode strips are pixels. Light is generated when current passes through the selected anode and cathode strips. Therefore, turning on/off the current that goes through strips determined which pixels will be displayed and an image is created. Even though PMOLED is easy to fabricate and manufacture, the external circuit that controls current source is relatively expensive. Comparing to other OLED types, PMOLED is less efficient mostly due power loss from diodes and the strips. Though, this type of OLED still consumes less power than LCD display. Therefore, PMOLED is the most power efficient in and best used for small displays ranging from 2” to 3”. Currently they are used in cell phones, music players, GPS, and portable displays.

(via howstuffworks, universal display ; image credit: howstuffworks and danawa.com)

Active RFIDs

2008-12-28T22:20:00.005-05:00

This is the third post of the Macroelectronics.org RFID series. Stay tuned.

An active RFID is similar to a passive RFID tag: It has similar ciruitry and an antenna to that of a passive RFID. The main difference between the two is that the active version has a battery incorporated to its circuitry. This battery can be the sole or partial source of the tag's power supply.

The advantages of an active RFID include a longer range reading distance. The power supply can amplify the signal and transmit it to farther distances. In addition, the power source to an active RFID can also power other sensors on the RFID, enabling it to send certain signals under certain circumstances.

However, with the RFID, the downside is to replace the battery when the battery is exhausted; Likewise, a serious downfall to an active RFID is its cost. The cost of a single active tag can cost twenty or more USD, which makes buying a couple to several thousand for any use quite pricey. Furthermore, using a battery also leads to a much more bulky RFID, compared to a passive RFID.

(via Technovelgy.com)

Passive RFIDs

2008-12-15T13:17:00.002-05:00

This is the second post of the Macroelectronics.org RFID series. Stay tuned.

Pasive RFIDs are tags that do not require a power source to operate. Instead, the reader for the RFID is operated on a voltage source. With this voltage source, the reader is able to construct a magnetic field when it senses a tag is near. From this, a current is induced through the magnetic field, which allows the tag to send its signal to the reader.

Most passive tags signal by backscattering the carrier wave from the reader. This means that the antenna has to be designed both to collect power from the incoming signal and also to transmit the outbound backscatter signal. The response of a passive RFID tag is not necessarily just an ID number: The tag chip can contain non-volatile data.

The reading and writing depend on the chosen radio frequency and the antenna design/size. Passive tags have a variety of ranges depending on the antenna incorporated into the tag. Some have a read distance ranging from about 11 cm (with near-field) and up to approximately 10 meters (with far-field)! There are even some tags that can reach up to 183 meters when combined with a phased array. Due to the simplicity in design they are also suitable for manufacture with a printing process for the antennas.

The lack of an onboard power supply means that the device can be quite small. Commercially available products exist that can be embedded in a sticker, or under the skin in the case of low frequency (LowFID) RFID tags. This information can be even retreived from over a couple hundred meters. Because of it's low-profile and simplicity, there are several applications for passive tags, ranging from inventory to paying for products remotely. More about its applications and setbacks will be found in upcoming posts.

(via Wikipedia, image credit: Sandia National Lab)

HP & FDC demo flexible, unbreakable displays

2008-12-10T10:03:00.002-05:00

On Dec. 8, 2008, HP and the Flexible Display Center (FDC) at Arizona State University (ASU) announced the first prototype of "affordable, flexible, unbreakable" electronic displays.

Flexible displays use up to 90 percent less materials by volume than conventional displays. The unbreakable displays were created by the FDC and HP using self-aligned imprint lithography (SAIL), a proprietary technology of HP Labs. SAIL is considered “self aligned” because the patterning information is imprinted on the substrate in such a way that perfect alignment is maintained regardless of process-induced distortion. SAIL enables the roll-to-roll printing manufacturing of the flexible displays.

It is expected that the flexible display market is to grow from $80 million in 2007 to $2.8 billion by 2013.

More details are here.

(Via HP. Image credit: FDC)

OLEDs: Advantages and Challenges

2008-12-04T02:14:00.011-05:00

This is the second post of the Macroelectronics.org OLEDs series. Stay tuned.

Advantages

Thinner and lighter - OLEDs are made out of organic layers , which allows OLED displays to be lighter and thinner than LCD or LED. The thin profile of OLEDs also leads to the flexibility of the displays. Thinner and lighter displays are preferable for mobile devices.
Brighter display with wider view angle- One of the important characteristics of OLEDs is that pixels generate light by themselves. By contrast, LCDs create images by filtering backlights to generate colors. Therefore, OLEDs produce brighter and clearer images comparing to LCDs. The emissive OLEDs also enable the wide view angle as much as 170 degrees.
Lower power consumption – OLED does not require backlighting which drains much power, therefore OLEDs are much more power efficient than LEDs. For example, OLED displays for mobile devices will lead to longer battery life. Currently, OLEDs are also being developed as the next generation of lighting source of high energy efficiency (see here for an earlier post).

Challenges

Lifetime – One of the grand challenges for OLEDs is their limited lifetime because OLEDs are composed of organic materials that are extremely vulnerable to water vapor and oxygen. High performance encapsulation technology for OLEDs is much desirable to achieve a device life time comparable to that of LCD. Such a technology, however, is still far from mature.
Manufacturing Cost – The stringent requirement of the fabrication environment for OLEDs results in the expensive manufacturing process of OLEDs. So far, there is no practical way to mass produce OLEDs at low costs. This also imposes another grand challenge to the widespread use of OLED products.

Even with these significant challenges, OLEDs are still being actively developed for various potential applications, some of which will be covered in subsequent posts of this series. So hang on.

(via howstuffworks, OLED-Info, and Wikipedia; image credit: Universal Display)

What are RFIDs?

2008-11-26T00:58:00.007-05:00

Macroelectronics.org will start a series of posts on RFIDs. Stay tuned.

RFIDs (Radio Frequency Identifications) are microchips of very small proportions that utilize radio frequencies to store and retrieve data. RFIDs were first used as espionage, the first devices capable to retain data through radio transponders.

There are two main parts of an RFID. One part is an integrated circuit for storing/processing information, modulating/demodulating a radio frequency signal, as well as other functions. The other part is an antenna then used to receive and send signals.

There are several types of RFIDs, such as passive, semi-passive, and active RFIDs. Passive RFIDs operate through inducing a magnetic field upon them, which generates current for them to work; on the other hand, semi-passive and active RFIDs require an internal source of power for them to function. More details about the different types of RFIDs will follow up in the coming posts in this series. Later in this series, we will also introduce the current and future applications of RFIDs.

(via Wikipedia, image credit: Rexam)

OLEDs: How it works?

2008-08-28T19:25:00.009-04:00

Macroelectronics.org will start a series of posts on OLEDs. Stay tuned.

OLEDs, or organic light-emitting diodes, are thin films of organic molecules that generate light when electricity is applied. OLEDs have a potential to provide shaper, crispier, and clearer display than today’s LEDs (Light-emiting diodes) and LCDs (Liquid crystal displays).

An OLED, with different layers of material, is only about 100-500 nanometers thick. It typically consists of five functional layers: substrate, anode, two organic layers (both conducting layer and emissive layer), and cathode. The substrate, usually made of glass or clear plastic, is used to support the OLED. When electrical current passes through cathode and anode, emissive layer receive electrons from the cathode, and the anode removes electrons from conductive layer. Once an electron leaves conductive layer, there is an “electron hole”. Then, extra electrons from emissive layer jump to conductive layer to fill electron holes. When an electron combines with an electron hole, there is a drop in the electron energy level and such an energy drop is released in form of visible light (e.g., photons). The color of the light produced depends on the material of the organic layer. Therefore, a color OLED display can be made by using different layers of organic material that emit different colors.

The following animation illustrates how OLEDs work:

(via HowStuffWorks and Wikipedia)

Macroelectronics.org: A World Top 100 Engineering Blog

2008-07-17T11:03:00.006-04:00

We are pleased to announce that www.macroelectronics.org was recently ranked No. 33 in the Top 100 Engineering Blogs (as of 17 July 2008, see here for detail list). The ranking is updating over the time. A real-time ranking badge has been embedded on the left-hand sidebar.

We cordially appreciate the constant support and interest of our readers, as well as the hard work of our diligent contributors of macroelectronics.org. Stay tuned, macroelectronics.org will always bring the latest progress in the flexible electronics to you.

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Thin Film Solar Cells: Konarka

2008-07-01T21:58:00.008-04:00

This is our fifth post in the Macroelectronics.org thin-film solar cell series.

Konarka is a company that develops solar panel using nano-enabled polymer photovoltaic materials. This polymer material, or as Konarka called PowerPlastic, is a semi-conductor organic material that are thin, lightweight, and very flexible. Comparing to traditional solar panel, PowerPlastic provides better performance, lower cost, and lower toxicity. Not only that, PowerPlastic can absorb low light level efficiently. The main component of Konarka’s photovoltaic cells is nanoscale titanium dioxide particles coating, a light-sensitive dye that generates electricity when light shines on.

PowerPlastic solar panel is created using roll to roll manufacturing process. Roll to roll process is the process in which transparent electrode, printed active material, primary electrode and substrate are printed onto transparent packaging to make a solar panel. This manufacturing process is inexpensive, environmental friendly, and simple. Currently, Konarka is invested by US military, the National Science Foundation, DARPA, and the Department of Energy, the Department of Commerece, etc. Konarka’s solar panel is a great prospect of future alternative energy source.

(via Konarka and Wikipedia, image credit: Konarka Technologies, Inc.)

Thin Film Solar Cells: PowerFilm

2008-06-11T00:23:00.006-04:00

This our fourth post in the Macroelectronics.org thin film solar cells series.

PowerFilm is the first and the only company now that use roll-to-roll manufacturing process to fabricate flexible solar panels. The flexible solar panels consist of several layers: transparent conductor, P-I-N device, back metal contact, and polymer substrate.
The polyimide substrate used for the panel makes panels flexible, lightweight, and as thin as 0.025 mm.
Thin film of amorphous silicon is used as the absorber layer in the flexible solar panels. Only 1% of silicon used in traditional solar cells is used.

The monolithic integration manufacturing process helps to reduce manufacturing costs and increase products durability because it eliminates labor costs and manual connections that can cause stress to the cells. Not only that, to improve solar cell durability, core solar panels are encapsulated between varieties of materials so that it can withstand different environment. PowerFilm has the capacity of make flexible solar panels of 13 inches wide and up to 2400 feet long.

(via powerfilm, image credit: PowerFilm.Inc)

Thin-Film Solar Cells: Miasolé

2008-05-23T00:39:00.008-04:00

This is our third post of the Macroelectronics.org thin-film solar cell series.

Miasolé is another influential thin-film solar cell company. Miasolé uses copper indium gallium selenide (CIGS) as a photon-absorber material. CIGS composes of copper, indium, gallium and selenium (CuInxGa(1-x)Se2). CIGS’s remarkable ability to absorb photon was discovered in 1970s. However, it was not in the market yet because there was no high-volume manufacturing technique. Miasolé establishes high-volume manufacturing technology that enables the company to commercialize CIGS layer solar cell in large industrial-scale.

Unlike crystalline silicon which is an indirect band-gap semiconductor, CIGS is a direct band-gap semiconductor, which can generate more power per unit of material. One micron thick CIGS can produce as much photoelectric effect as 200-300 microns thick silicon crystalline. Therefore, CIGS is less expensive than traditional solar cell. Because only small amount of CIGS is needed on a film, the film can be made very thin making it flexible. Not only that, another advantage of CIGS film over crystalline silicon is that CIGS is more efficient in low angle and light intensity, which makes CIGS solar cell more feasible in real-world applications where sky will not be always clear and sun will not be shinning straight down into the solar cell. In overall, Miasolé’s solar cells are thin, light-weight, flexible, practical, and low cost (compare to traditional solar cell).

(via Miasolé and Wikipedia; image credit: Miasole (SolarPlaza))

Thin-Film Solar Cells- NanoSolar's 7 Areas of Innovation

2008-05-07T15:28:00.010-04:00

This is the second post of Macroelectronics.org's series on thin-film solar cells. We'll talk about the production, cost, and efficiency of thin-film solar cells.

Several companies, such as Nanosolar, have now come out with rollable thin-film solar cells, which are one hundred times thinner than traditional solar cells, and can also be made one hundred times faster than traditional manufacture procedure. In making rollable thin-film solar cells, a type of ink that is able to conduct electricity is printed on a thin, conductive substrate. This new technology is superior to the traditional solar cells not only because it is far cheaper to produce given the low cost of the ink and the substrate, but also because it produces more energy and power than traditional solar cells.

Companies such as Nanosolar have been on the cutting edge of this technology. Nanosolar's technology is based upon their "7 Areas of Innovation" including:

Nanoparticle Ink
Semiconductor Base for Printing
Conductive Substrate
Roll-to-Roll Processing
Low-Cost Top Electrode
Sorted Cell Assembly
High Current Panel

More detail information can be found here on their "7 Areas of Innovation." Convenience and efficiency may be a great advantage to Nanosolar's thin-film technology, what also adds to the benefits of their product is the durability: the solar cells are able to withstand temperatures from -40 to +85 degrees Celcius, allowing them to be used virtually anywhere sunshine is plentiful.

Check out the following KQED video on Nanosolar:

(via Wikipedia & Nanosolar; Photo and video Courtesy: Nanosolar , KQED)

Thin Film Solar Cells - An Introduction

2008-04-30T01:42:00.003-04:00

(Macroelectronics.org will start a series on thin film flexible solar cells. Stay tuned!)

Solar cells are devices that convert solar energy to electrical energy. The process in which the solar cell converts solar energy to electricity is called photovoltaic. Traditional solar cell is mostly made out of silicon, a well-known semi-conductor. When the sunlight hits the solar cell, photons from the sunlight is absorbed by the semi-conductor. The photons then hit the atoms causing electrons to be kicked out of atoms. The movement of electrons produces electricity (see figure).

Silicon is a brittle material and fractures at very small deformation. This poses a significant challenge to make and handle large area solar cell panels. To further reduce the cost to harvest solar energy, there have been emerging efforts on developing thin film solar cells that can be fabricated on thin plastic foils by a roll-to-roll process. The functional device material used in such thin film solar cells include organics/polymer film, gallium arsenide, copper-indium selenide, etc. However, so far thin-film solar cells are not as efficient as conventional solar cells. In the subsequent posts of this series, we'll review the currently available technologies of thin film solar cells.

"Morph": Nokia's new concept phone

2008-03-10T00:34:00.004-04:00

Recently, Nokia came up with a new cellular phone concept, “Morph.” This concept with University of Cambridge’s collaboration was introduced during The Museum of Modern Art’s “Design and the Elastic Mind” exhibition in New York.

Morph offers its flexible and stretchable properties or may be even an ability to clean itself for mobile phone. Morph will comprise of two basic units: a communications unit and a sensing unit. The communications unit will contain three possible functions: regular cellular phone, video conference device, or ear-clip mobile phone. The second unit, a sensing unit, will comprise of flexible/stretchable sensing screen that acts like keyboard, bendable sensors that is wearable, and sensors that can be integrated with other devices. For this concept to work, Nokia Research Center and University of Cambridge will focus their researches largely on nanotechnology and nanomaterial.

Check out the following YouTube video on Morph:

(via Business Weekly (UK) , The Museum of Modern Art , image credit: The Museum of Modern Art)

Bionic Contact Lens

2008-02-03T15:09:00.000-05:00

Researchers at the University of Washington led by Babak Parviz, an assistant professor of electrical engineering at the University of Washington, created a bionic contact lens. This contact lens is embedded with light-emitting diodes, electronic circuits and small antenna. Therefore, it is possible to see an image through contact lens. In the future, this research can be developed into a flexible display screen contact lens where people can surf internet or watch TV show through contact lens. This research can transform and benefit mobile device manufacturers if it is successful.

The researchers overcame obstacles to integrate the fabrication process for microchips, light-emitting diodes, and polymers used for contact lenses. The layer on top has electronics circuits that is as thin as one-thousandth of the width of a human hair and diodes are very small that almost 100 of them can fit in one inch. To bind circuits with the lens, the researchers constructed a multiple receptor sites that attracted a different component by mimicking capillary forces that plants used to push water up thought their roots. For this prototype, the lens surface hold antenna, metal wires for the circuits, and red light-emitting diodes on the lens surface.

Even though bionic lens is a very promising technology, there are some issues and challenges. Researchers now are focusing on the image quality of the lens because to see an object, human’s normal focus is 25 centimeters in front of the eyes. However, image is now right at the surface of the contact lens. Also, they are trying to find a way to provide adequate power for the contact lens. Currently, the prototype’s antenna can collect radio frequency waves and turn them into energy. The goal of this contact lens is to let user wear this device comfortably and so far, tested rabbits can tolerate bionic lenses for 20 minutes.

(via msnbc , image credit: University of Washington)

LG Philips high resolution color e-paper

2008-01-17T11:38:00.000-05:00

LG Philips LCD recently debuted the world's highest resolution 14.3-inch flexible color E-paper display at the Consumer Electronics Show (CES) 2008. The 14.3-inch E-paper display is equivalent in size to an A4 sheet of paper, with a resolution of 1280 by 800 pixels, and can display 16.7 million colors. The super slim display is less than 300 micrometers thick.

LG.Philips uses metal foil as the substrates to thin-film transistors (TFT), allowing the display to recover its original shape after being bent. Furthermore, the view angle of the display reaches a full 180 degrees, so that images always appear crisp, even when the display is bent.

LG.Philips LCD will also unveil the highest resolution mono flexible E-paper which is similar in size to a B5 size paper and it plans to launch this mono flexible E-paper in 2008.

(via CES 2008)

How e-paper works: Cholesteric Liquid Crystal

2007-12-04T13:17:00.000-05:00

Cholesteric Liquid Crystal is another technology that holds great promise in making future e-paper.

Liquid crystal is a state of a matter in which molecules maintain their orientations and their respected positions just like solid, but they can move anywhere just like liquid. These liquid crystals are affected by electrical voltages. When electrical voltage is applied, molecules in liquid crystal rotate into specific angle depending on magnitude of electrical voltage.

Cholesteric liquid crystals contain nematic mesogenic molecules with chiral center. Basically, cholesteric liquid crystals are liquid crystals in which their rigid parts are pointing at the same direction and their molecular structure in the center are differed from its mirror image. Their molecules are in the shape of helix and are stacked together. The distance that the director (assigned direction of a molecule) takes to rotate in one full turn is called the “pitch”. This is important because in cholesteric nematic phase (the phase where molecules are not in any positional order in liquid crystal), helical structure of the molecules can filter reflected light into a specific wavelength which happens to equal to its pitch from the mesophase. Therefore, to create an image, electrical voltage is applied to the cholesteric liquid crystal so that molecules can rotate and produce a pitch where certain colors can be generated.

Cholesteric liquid crystal works great for e-paper because it is bistable meaning that it requires no power to sustain an image on its display. ChLCD uses reflected light from outside source thus required even less power. However, this technology’s downfall is its low reflective brightness of the display. Major electronics companies such as IBM, Fujitsu, and HP are developing ChLCD technology for e-paper into commercial use.

This is the third post of our "How e-paper works?" series. Other posts are available at:

(via http://electronics.howstuffworks.com/ and http://plc.cwru.edu/ , image credit: Kent Display)

How e-paper works? -- E-Ink

2007-11-27T02:18:00.001-05:00

Another enabling technology for e-paper is called E-Ink. It was first developed byJoseph Jacobson an associate professor at M.I.T. Media Lab. Joseph and his students with Russell J. Wilcox who graduated from Harvard Business School found E-Ink Corporation in 1997.

E-Ink contains millions of tiny capsules with diameter as a human hair, each of which is filled with fluid with positively charged white particles and negatively charged black particles. When positive electric field is applied, black particles move to the top of the capsules thus displaying image in black color. Vise versa, when negative electric field is applied, white color is shown.

E-Ink is bistable. Bistable means that when ink moves to the surface of the capsules, it can stay there without any power input. This implies that electrical power is needed only to change from black to white or white to black color. Therefore, energy power required is minimal. However, this technology’s downfall is its slow refreshing time.

Now, with the collaboration between E-Ink and colar filter producer Toppan Printing in Japan, multicolor e-paper can become possible in the near future. So far, E-Ink technology has been used in several E-book devices , such as the Sony Reader, the iLiad, the Cybook Gen3, and Amazon Kindle.

(via http://www.prism.washington.edu/ and http://www.tfot.info/)

(Video credit: www.tfot.info)

This is the second post of our "How e-paper works?" series. Other posts are available at:

How e-paper works? -- Gyricon

How E-Paper Works? -- Gyricon

2007-11-11T19:12:00.000-05:00

Gyricon, the first enabling technology of e-paper, was developed a team led by Nick Sheridon at Xerox’s Palo Alto Research Center (PARC) in early 1970s.

Gyricon contains a lots of small spherical beads, sandwiched in between two thin transparent plastic sheet. Each bead is bichromal, meaning it contains two opposite colors (e.g., black and white) on each side of the sphere. These beads are imbedded in cavities filled with oil that allows these beads to rotate freely. Each side of the bead has its own electrical charge (positive or negative). These beads are rotated by exposure to an electrical charge; they rotate fully to display as black or white, or partially (in response to lower electrical charges), to display a range of grey shades. Images are created by the beads with distributed orientation, and are bi-stable: they remain fixed in position until another electrical charge is applied to change the orientation of the beads.

The following video demonstrates how Gyricon works:

(via http://www2.parc.com/)

This is the first post of our "How e-paper works?" series. Other posts are available at:

How e-paper works? -- E-Ink

Electronic Paper: History and Future

2007-10-29T00:49:00.000-04:00

The following is a brief Summary of an interview with experts in e-Paper, including the "father" of e-Paper, Nicholas K. Sheridon (the gentlemen in the photo)

Research on e-paper started roughly 35 years ago. One of the Xerox’s teams led by Nicholas K. Sheridon invented Gyricon rotating ball display, which was the groundwork of the first e-paper. Xerox’s concept in the early 70s was the “paperless” office. However, more papers were used after the widespread of personal computers. Computer monitors are uncomfortable to human’s eye unlike ink on papers. Therefore, Xerox tried to develop e-paper, an electronic based paper that closely resembles ink on paper. Yet, 35 years since the invention of e-paper, it does not enter the market.

The reason why it took so long for e-paper to enter the market was because the early Gyricon technology was expensive and had a poor resolution. Newer solutions to e-paper are electrophoretic frontplane and cholesteric liquid crystal technology. Though, no current display technology is paper-like yet. E-paper has to be thin, flexible, and comfortable to human’s eyes while consumed minimal amount of power. One of the biggest obstacles is the cost of e-paper. There is no doubt that this technology will be widespread when it cheaper than 100$. Many companies such as E ink, SiPix, Polymervision, IBM, Sony, Siemens, etc. see e-paper as a promising technology. Thus, they continue to develop commercialized e-paper products.

Currently, applications of e-paper are used for advertising billboards, display screens for MP3 player or even on microwave. Also, e-paper can also be used as a new method for labeling foods and drugs. In the next five years, electronic signs and billboards made from e-paper should be widespread. In 2015, e-paper products should be available for most people and become a real mass market.

(via www.tfot.info, image credit: Xerox)