Transparency - Page 4

Powerbooster Technology (based in Shanghai) developed a graphene-based flexible touch-panels for mobile devices. The company says that graphene is cheaper and stronger than ITO (traditionally used for touch panels). The company plans to invest $150 million in the next three years in order to bring their solutions to the market.

Powerbooster is partnering with Bluestone Global Tech to supply them with graphene. They say they already started to produce these touch panels - in fact they claim that they already sell around 2 million touch panels per month, apparently to mid-sized Chinese smartphone makers (this is rather surprising, hopefully we'll learn more soon). They aim to get the first products with their graphene touch screens in the market by the end of 2013.

Researchers from the University of Copenhagen and the Chinese Academy of Sciences developed a transparent transistor made from just one molecular monolayer graphene. The graphene was used as transparent top-contacts in this design. The new "molecular computer chip" is built from three layers: gold, molecular components and graphene. The molecular transistor is switched on and of using a light impulse.

While such chips may be used to make integrated circuits in the future, the first application the researchers found was testing of molecular electronics. The new chip enables molecular placement with great precision, which speeds up molecular research.

Researchers from Korea's Sungkyunkwan University developed a highly flexible and transparent memory device using graphene electrodes (both and anode and the cathode). This is the first time graphene is used for the bottom electrode in such a device, and this was achieved by using a chemical union of the bottom electrode with the molecular film of organic molecules (which is placed between the two electrodes).

This is not the first graphene based flexible memory device. In October 2012 researchers from Rice University developed highly transparent (95%), flexible, nonvolatile resistive memory devices based on silicon oxide (SiOx) and graphene. In March 2013 Researchers from EPFL designed a new flexible, small and fast flash memory cell prototype from graphene and Molybdenite (MoS2).

Researchers from Purdue University developed a new transparent electrode made from silver nanowires and graphene. ITO, which is currently used for transparent electrodes in touch displays is expensive, non-flexible, brittle and rare. Silver Nanowires is a promising material to replace ITO - and it is already being commercialized for LCD and OLED displays.

The researchers say that coating the silver nanowires with graphene sheets changed the resistance of the electrodes - which dropped to only 22 ohms per square (which is five times better than ITO which has a sheet resistance of 100 ohms per square).

Researchers from University of Exeter have developed a new flexible, transparent and ultra-lightweight photodetector device made from graphene and graphExeter (a room-temperature transparent conductor discovered at the University of Exeter in 2012). The new device can also be used to generate electricity. It's only a few atoms thick and can be woven into textiles to create photovoltaic fabrics.

The researchers say that the efficiency of the new device is similar to opaque devices based on graphene and metals (Nokia, for example, is working on graphene-based photo detectors). The new device does not contain any metals. It can detect light across the entire visible light spectrum.

Bluestone Global Tech released two short videos introducing Graphene. The first focuses on the different graphene properties (strength, flexibility, conductivity, etc):

The second video is all about the different graphene applications, such as displays, LEDs, touch screens, batteries, solar cells and conductive wires

Update: read more about Duke's graphene-based artifical muscles research here

Researchers from Duke University are developing ways to control the crumpling and unfolding of large area graphene. By attaching the graphene to a pre-stretched rubber film. When the film was relaxed, parts of the graphene sheet detached, forming an attached-detached pattern with a feature size of a few nanometers. When the film was stretched again, the adhered spots of graphene pulled on the crumpled areas to unfold the sheet.

So basically stretching and relaxing a rubber film, even manually can crumple and unfold large area graphene sheets. This opens up the possibility of all sorts of applications. One example is a graphene film that can be changed from transparent to opaque (it is transparent when stretched but opaque when crumpled).

Researchers from Korea developed a new gold-doped graphene based transparent and current-spreading electrode (TCSE) for UV LEDs. Graphene was already studied as a conductive layer for UV LEDs, and now it turns out that doping it with gold improves the performance.  A gold-doped graphene LED features about 20% more emission compared to an ITO LED.

UV (300-400nm) LEDs are useful in several applications such as germicidal instrumentation, biological agent identification, chemical sensing, fluorescence excitation, and optical data storage. UV LEDs can also be used to emit white light (through phosphorescence).

Nobel Prize-winner (together with Andre Geim) Professor and Kostya Novoselov Professor Volodya Falko from Lancaster University have released a graphene roadmap. The roadmap discusses the different possible applications for graphene and also the different ways to produce the material.

The authors says that the first key application is conductors for touch-screen displays (replacing ITO), where they expect can be commercialized within 3-5 years. They also see rollable e-paper displays soon - prototypes could appear in 2015. Come 2020, we can expect graphene-based devices such as photo-detectors, wireless communications and THz generators. Replacing silicon and delivering anti-cancer drugs are interesting applications too - but these will only be possible at around 2030.

Researchers from the Rice University have developed highly transparent (95%), flexible, nonvolatile resistive memory devices based on silicon oxide (SiOx) and graphene. This research began in 2008 when they discovered that silicon oxide itself can be a switch. The researchers placed the SiOx and crossbar graphene terminals on flexible plastic.

The new design is much simpler than current flash memory devices as it uses only two terminals and can be stacked in 3D configurations. This can vastly increase the density of memory devices. This memory can also be made in a multi-state mode (i.e. not just binary 1/0).