2015年经济学人 显示屏 新的电子图案显示方法

Display screens

Going through a phase

A new way to create electronic images

Wave of the future?

LIQUID-CRYSTAL displays are a familiar and ubiquitous technology. But if Harish Bhaskaran of Oxford¹ University is right, their days may be numbered.

The essential feature of LCDs is that the pixels in them switch between amorphous² and crystal-like phases, which changes their optical properties.

In a paper in this week's Nature, Dr Bhaskaran and his colleagues describe something similar in a solid material.

At the least, that would stop the messy abstract-impressionist patterns which happen when an LCD is dropped too hard.

At most, it might open up a new range of applications, from clothes that change colour to dimmable windscreens.

Solid phase-change materials are already used to store data in optical memory disks.

They are also being considered for use in memory chips, because the switch between amorphous and crystalline states alters their electrical properties in ways that can store electronic bits of data.

Dr Bhaskaran, though, has shown that thin enough films of the right sort of material can be made to change colour, too.

This property would make them suitable both for displays that rely on reflected light (so-called electronic paper) and the older, backlit sort that rely on transmitted light.

The resulting displays would be thin and could be flexible if printed on the right material—increasing the range of applications they might be used in.

And they would consume little power, since energy need be used only when a pixel has to be flipped³ from one phase to another.

The researchers' material of choice is an alloy⁴ of germanium, antimony and tellurium.

Both the crystalline and the amorphous phases of this substance are stable at any temperature a device is likely to experience, and thin films of it are more or less transparent⁵.

The power needed to effect the phase change could be fed to individual pixels by electrodes made of indium tin oxide⁶, which is also transparent.

The colour of a pixel would depend not only on its phase, but also on its thickness, which would affect the way light waves being reflected within it interfere⁷ with one another,

cancelling out some frequencies while amplifying⁸ others. (The effect is similar to the creation of colours by a thin layer of oil on a puddle⁹.)

Generally, the alloy layer needs to be thinner than 20 nanometres for that to happen.

To demonstrate their idea, the researchers sprayed films of their alloy onto pieces of silicon¹⁰, quartz¹¹ and plastic.

They then used a device called an atomic-force microscope, which has a tip a few nanometres across,

to apply appropriate electric currents in a grid¹² pattern across the film's surface. This grid mimicked¹³ an array of pixels, creating a stable pattern.

The result, as their picture of a Japanese wave shows, is a recognisable image—if not, yet, a perfect one.

Adding the indium-tin-oxide electrodes is a more complicated process, but to show it can be done in principle, Dr Bhaskaran has made a single pixel this way.

Whether his idea will get off the lab bench and into the shops remains¹⁴ to be seen.

It is by no means the only suggestion around for a new generation of display screens. But it looks plausible¹⁵.

1 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

2 amorphous   

adj.无定形的

参考例句：

• There was a weakening of the intermolecular bonds,primarily in the amorphous region of the polymer.分子间键合减弱，尤其在聚合物的无定形区内更为明显。
• It is an amorphous colorless or white powder.它是一种无定形的无色或白色粉末。

3 flipped   

轻弹( flip的过去式和过去分词 )； 按（开关）； 快速翻转； 急挥

参考例句：

• The plane flipped and crashed. 飞机猛地翻转，撞毁了。
• The carter flipped at the horse with his whip. 赶大车的人扬鞭朝着马轻轻地抽打。

4 alloy   

n.合金，(金属的)成色

参考例句：

• The company produces titanium alloy.该公司生产钛合金。
• Bronze is an alloy of copper and tin.青铜是铜和锡的合金。

5 transparent   

adj.明显的，无疑的；透明的

参考例句：

• The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
• The window glass is transparent.窗玻璃是透明的。

6 oxide   

n.氧化物

参考例句：

• Oxide is usually seen in our daily life.在我们的日常生活中氧化物很常见。
• How can you get rid of this oxide coating?你们该怎样除去这些氧化皮？

7 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

8 amplifying   

放大，扩大( amplify的现在分词 )； 增强； 详述

参考例句：

• Often they use borrowed funds, amplifying their gains and losses. 他们通常会用借贷的资金交易，从而放大收益或损失。
• An amplifying type (or analog) device, as opposed to digital device. 放大器类（或模拟）器件，相对于数字器件而言的。

9 puddle   

n.(雨)水坑，泥潭

参考例句：

• The boy hopped the mud puddle and ran down the walk.这个男孩跳过泥坑，沿着人行道跑了。
• She tripped over and landed in a puddle.她绊了一下，跌在水坑里。

10 silicon   

n.硅(旧名矽)

参考例句：

• This company pioneered the use of silicon chip.这家公司开创了使用硅片的方法。
• A chip is a piece of silicon about the size of a postage stamp.芯片就是一枚邮票大小的硅片。

11 quartz   

n.石英

参考例句：

• There is a great deal quartz in those mountains.那些山里蕴藏着大量石英。
• The quartz watch keeps good time.石英表走时准。

12 grid   

n.高压输电线路网；地图坐标方格；格栅

参考例句：

• In this application,the carrier is used to encapsulate the grid.在这种情况下，要用载体把格栅密封起来。
• Modern gauges consist of metal foil in the form of a grid.现代应变仪则由网格形式的金属片组成。

13 mimicked   

v.（尤指为了逗乐而）模仿( mimic的过去式和过去分词 )；酷似

参考例句：

• He mimicked her upper-class accent. 他模仿她那上流社会的腔调。 来自辞典例句
• The boy mimicked his father's voice and set everyone off laughing. 男孩模仿他父亲的嗓音，使大家都大笑起来。 来自辞典例句

14 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

15 plausible   

adj.似真实的，似乎有理的，似乎可信的

参考例句：

• His story sounded plausible.他说的那番话似乎是真实的。
• Her story sounded perfectly plausible.她的说辞听起来言之有理。