Why a sausage can do what your gloves cannot - Charles Wallace and Sajan Saini

譯者: Kristin Yu 審譯者: Helen Chang

In 2010, South Korea experienced a particularly cold winter.

韓國在 2010年 經歷了 非常寒冷的冬天。

People couldn't activate their smartphones while wearing gloves,

人們戴著手套無法啟動智能手機，

so they began wielding snack sausages—

於是他們開始使用香腸零食——

causing one company to see a 40% rise in sausage sales.

致使一家公司 增加了40% 的香腸銷量。

So, what could sausages do that gloves couldn’t?

那麼，到底什麼是香腸做得到， 而手套所不能及的呢？

In other words, how do touchscreens actually work?

換言之，觸摸屏是如何運作的？

In 1965, the first ever touchscreen was invented

1965年，第一塊觸摸屏被發明出來

to help British air traffic controllers efficiently update flight plans.

用於協助英國空中交通管制員 有效地更新飛行計劃。

However, the technology was too unwieldy and expensive for widespread use.

然而，這項技術運作不靈便 且過於昂貴，無法廣泛應用。

Over the following decades,

在接下來的幾十年裡，

engineers further developed this technology

工程師進一步開發了這項技術

and experimented with alternative kinds of touchscreens.

並對觸摸屏的 可替代種類進行了實驗。

Soon, resistive touchscreens dominated the market.

很快，電阻式觸摸屏就佔領了市場。

But then, in 2007, Apple released the first iPhone.

但後來，在2007年， 蘋果公司推出了第一代iPhone。

It was a breakthrough, yet it functioned using the same principle

這是一個重大突破， 但它的工作原理

as the first touchscreen: capacitance.

仍與第一塊觸摸屏相同：電容式。

Nowadays, capacitive and resistive touchscreens

如今，電容式和電阻式觸摸屏

are two of the most common types.

是兩種最常見的類型。

Both use an external input to complete their electric circuits.

兩者都用一個外部輸入 來形成完整的電路。

In conductive materials, electrons flow around atoms,

在導電材料中， 電子圍繞原子流動，

forming an electric current.

形成電流。

In contrast to insulators,

與絕緣體相反，

the electrons in conductors are weakly bound and flow easily.

導體中的電子束縛力較弱， 容易流動。

A resistive touchscreen has two layers.

電阻式觸摸屏有兩層。

The top is a clear, flexible material— usually plastic—

上層是透明的、有弹性的材料—— 通常是塑膠做的 ——

while the bottom is something rigid, like glass.

而下層是堅固的，如玻璃一般。

These layers are coated with a conductive substance

這兩層塗有導電物質

and separated by a thin gap.

由一個細小的間隙隔開。

When something pushes hard enough, the layers connect,

當有東西用力推時，兩層便接觸，

completing the electric circuit.

連接起整個電路。

This causes a change in voltage that the machine’s software reacts to.

這會導致電壓發生變化， 使得設備的軟體起作用。

Resistive touchscreens can be a little unresponsive,

電阻式觸摸屏可能有些反應遲鈍，

but they're generally cheap and durable,

但它們一般都很便宜和耐用，

so they're favored for industrial or mass use.

所以在工業或大眾規模中受到青睞。

A vast majority of the touchscreens produced in 2007 were resistive.

2007年生產的 絕大部分觸摸屏是電阻式的。

But in the years following the iPhone’s release,

但在iPhone發布後的幾年裡，

most became capacitive.

大多數都變成了電容式。

Individual models vary, but smartphone touchscreens today

每台手機型號有所不同， 但如今的智能手機觸摸屏

typically consist of a protective, insulating glass exterior

通常由保護和絕緣的外玻璃

and an LCD screen at the bottom that produces the images you see.

以及在底部 生成你所看到的圖像的液晶屏組成。

Between the glass exterior and the LCD screen are several sheets.

在外玻璃與LCD屏幕之間 有許多層薄片。

One is lined with rows of a transparent, conductive material

其中一層佈滿了 一排排透明的導電材料，

that carry an alternating electric current.

承載著交流電。

A thin insulating layer separates these conductive lines from others

一層極薄絕緣層上的導線

that are arranged as columns.

將排列成列的導線分隔開。

One on top of the other, the lines form a grid.

如此從上至下堆疊起來， 這些導線形成一個網格。

The points where they intersect are called nodes.

它們相交的點被稱為節點。

The phone's battery draws electrons along the first layer of lines,

手機的電池 沿著第一層線路吸引電子，

and some electrons accumulate at every node,

每個節點上都積累一些電子，

creating a small electric field.

形成一個小電場。

These screens are called capacitive touchscreens

這些屏幕被稱為電容式觸摸屏，

because the nodes act like capacitors by storing charge.

因為它的節點工作原理 和電容器儲存電荷相同。

They’re generally easier to use than resistive touchscreens

它們通常 比電阻式觸摸屏更容易使用

because they interact directly with your finger without the application of force.

因為它不需要用力按壓 就能直接與你的手指互動。

Your body is a great conductor and is constantly transmitting electric currents.

你的身體是一個良好的導體， 不斷地傳輸電流。

Why? Because about 60% of you is water.

為什麼？ 因為你的身體約60%是水組成的。

Now, while chemically pure water is an insulator,

雖然化學上的純水是絕緣體，

most water is impure.

但大多數水不是純水。

The water inside you is loaded with ions—

你體內的水充滿了離子——

atoms or molecules that have a net electrical charge.

具有淨電荷的原子或分子。

So when you click on an app, your finger functions like a third electrical line.

因此，當你點擊一個應用程序時， 你的手指就像第三條電線。

It interacts with the existing electric field,

它與現有的電場相互作用，

which induces a weak electric current that travels through your finger

導致微弱的電流通過你的手指流動，

and eventually back into the phone.

最終回到手機中。

This changes the amount of charge at the affected nodes.

這會改變受影響節點的電荷量。

And voltage measurements along the second layer of lines

而沿著第二層線路的電壓測量

tell the phone’s microprocessor which part of the screen is being touched.

告訴手機的微處理器， 屏幕的哪個部分被觸摸到了。

However, if you try using a smartphone while your hands are wet or gloved,

但是，如果你嘗試在雙手潮濕 或戴手套時使用智能手機，

you'll probably have some trouble.

你可能會遇到一些麻煩。

Both interrupt the electrical connection between your finger and phone.

這兩者都中斷了 你的手指與手機之間的電連接。

If water is splashed across the screen, it might trigger many underlying nodes,

如果水濺到屏幕上， 可能會觸發許多底層節點，

and the phone could act like you’ve touched it in multiple places at once.

手機可能會像 你一次在多個地方觸摸它一樣。

On the other hand, gloves are insulators, so the charge has nowhere to go.

另一方面，手套是絕緣體， 所以電荷無處可去。

Meanwhile, objects that conduct electricity about as well as your finger—

於此同時， 與你的手指一樣導電的物體——

like banana peels and certain processed meats—

例如香蕉皮和一些加工肉類——

can all activate the screen—

都可以激活屏幕——

knowledge that can come in clutch, when you’re in a pickle.

一個當你陷入困境時， 可以發揮關鍵作用的知識。