Apple, too, has a bagful of haptic-feedback technologies like 3D Touch, Force Touch, Taptic Engine inside Apple Watch and vibration patterns for ringtones and notifications. However, haptic tech firm Immersion has filed lawsuits against Apple claiming that these infringe on Immersion’s patents.

Will graphene and graphics get along

Since its discovery in the early 2000s, graphene has been touted as a magic material that has the potential to disrupt many an industry. It is basically a single-atom thick layer of carbon, achieved by shaving off layer after layer off graphite. Scientists propose innumerable uses for graphene, right from optics to semiconductors.

Tomas Palacios, who heads Centre for Graphene Devices and 2D systems at Massachusetts Institute of Technology (MIT), is one such scientist exploring the applications of graphene. He has several radical ideas, of which one is described by him as display on demand.

He believes that graphene could turn everyday objects like coffee cups and shoes into devices that can easily compile and transmit information. “Basically, everything around us will be able to convert itself into a display on demand,” he said during a newspaper interview.

To implement this, his team is developing a 3D printer that uses graphene as its ink. These objects would have electrical intelligence built into these. Graphene with its electrical and optical properties could enable the object itself to turn into a display when required.

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Fig. 2: Basic working principle of Bodle Technologies’ optoelectronic framework based platform technology

There have been earlier attempts to make awesome displays with graphene. Researchers from University of Manchester and University of Sheffield, for example, came up with a prototype semi-transparent, flexible, grapheme based LED display that could be used in phones, tablets and even televisions. The super-thin display was just 10 atoms to 40 atoms thick and could emit a sheet of light across its entire surface.

Samsung, which has developed a method of synthesising large-area, single-crystal wafer-scale graphene, also believes that graphene is the perfect material for use in flexible displays, wearables and other next-generation electronic devices. There are rumours that the company is already testing graphene based touchscreens.

Bodle’s bid for power

If flexibility is one requirement for future displays, then power efficiency is equally important. If you are bound to have devices all around you, you would certainly not want to keep charging all of these.

Bodle Technologies, a UK based startup, is working on a technology that could be used to make super-efficient displays that require almost no power at all. Their tech revolves around ultra-thin structures made using well-known and well-characterised materials including phase-change materials. This structure can manipulate light using electrical, optical or mechanical means.

According to the company, “It can be used to filter, steer or dim light at a flick of a switch and, most importantly, consumes very little or no power after switching.” This optoelectronic framework based platform technology can be used for developing low-power, flexible displays, smartwindows and much more.

Personal home theatre, anyone

Head-mounted displays, which were clunky and cumbersome at one point of time, are now sleek, lightweight and power-efficient. No wonder these devices, like Samsung GearVR, are touted to be more than gaming devices. These virtual reality (VR) displays have the potential to turn into personal home theatres, giving you an immersive, comfortable and personalised movie experience.

However, holographic displays that are likely to become popular in the next five to ten years are likely to put today’s 3D, VR and AR displays to shame. Holographic and volumetric displays appear to give an object mass. So you actually feel as if you are reaching out and holding an object.

There are several types of holographic displays. Of these, augmented holographic displays, which embed 3D objects into your surroundings, as if these were real, are already here. Products like Microsoft HoloLens and MagicLeap are examples of augmented holographic displays that provide an interactive, customisable experience.

In another class of holographic displays, nanophotonic devices manipulate light to achieve moving, full-colour holograms. These devices manipulate light at the source rather than trick the eye using middleware like glasses.

Several teams across the world, including one at Griffith University, Australia, are trying to develop such systems using graphene oxides and laser pulses to control the refractive index and wavelength of light. A nano-photonic holographic display does not require glasses, which means several people can view it. It is also potentially scalable to any size. However, it needs a wall to work and cannot project onto thin air.

If projecting onto thin air is what you really want, then you will get that, too. A team of researchers from Aerial Burton and multiple Japanese universities recently demonstrated a system that projects pixie-shape holograms called Fairy Lights into thin air. What makes these holograms all the more special is that these respond to human touch. The system uses femtosecond lasers, which can stimulate physical matter to emit light in 3D form.

Micro-LEDs to give OLEDs a good chase

Display experts consider micro-LEDs a technology worth watching. Micro-LED is an emerging display technology that uses arrays of microscopic LEDs as individual pixel elements. The tech offers benefits like greater contrast, faster response times and low energy consumption. While larger micro-LED displays are still too difficult to manufacture, experts feel that these displays make sense for smaller devices like smartwatches. That explains why Apple acquired LuxVue, a company working on micro-LED displays.

That said, perhaps micro-LED might emerge in larger formats. When John Rogers and Chris Bower of X-Celeprint proposed the use of micro-LEDs for multifunctional display systems at a conference last year, they first described a process for making multiple layers of LEDs with sacrificial layers in between that allow the layers to be lifted off. The company has developed a technology for transfer-printing of chips using elastomeric stamps utilising peel-rate-dependent adhesion.

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If that does not make sense, let us turn to industry expert Kim Werner’s simplified explanation on Display Daily: “To oversimplify shamelessly, if you place the stamp on the layer of chips and peel it off quickly, the chips adhere to the stamp. Impress the stamp on the target substrate and peel it off slowly, the chips adhere to the target. This is also impressive, but it still does not create LED arrays any larger than the original lattice-matched arrays.

“As it turns out, it is relatively simple to impose patterns on stamps that result in picking up every tenth, twentieth or nth LED before depositing these on the substrate. In this way, you can go from the dense array of the original wafer to a sparse array on the target substrate. In principal, this allows you to make µ-ILED displays of virtually any diagonal.”

Using this technology, X-Celeprint has made 150mm stamps. According to Bower, making larger ones is just a matter of engineering, not science.

Nature-inspired display tech

The very concept of display is in many ways inspired by nature. No wonder scientists continue to observe nature—from the butterfly’s wings to the woodcock’s 360-degree vision—to develop better display systems.

In one recent venture, scientists from Harvard University and MIT learnt a few lessons from a type of mollusc called the blue-rayed limpet. Limpets have two optical structures within their shell. These are configured to reflect blue light while absorbing all other wavelengths of incoming light, resulting in a blue-striped appearance.

In an attempt to understand where the stripes came from, researchers decided to take a close look at the translucent shells using 2D and 3D structural analysis to reveal the 3D nanoarchitecture of the photonic structures embedded in the shells. The shells’ top and bottom layers were relatively uniform, with dense stacks of calcium-carbonate platelets and thin organic structures.

As they got about 30 microns under the shell surface, they found regular plates of calcium-carbonate morphed into a multi-layered structure with regular spacing between layers, like a zigzag pattern.

This could potentially serve as a design guide for engineering colour-selective, controllable, transparent displays that require no internal light source. This technology can be used in windows and glasses, which need to be transparent and at the same time overlay AR content, like say, a map. In a news release, one of the researchers said, “We believe that the limpet’s approach to displaying colour patterns in a translucent shell could serve as a starting point for developing such displays.”

Everywhere we look, there is another creature that inspires a better display, another device that needs a better display and another team ready to work on it. Indeed, there is a lot to look forward to in the coming years.

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Janani Gopalakrishnan Vikram is a technically-qualified freelance writer, editor and hands-on mom based in Chennai

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