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Science and Technology Three-dimensional printing An image of the future
科技 3D印刷 印刷未來
One of the biggest manufacturers in the world gives 3D printing a go
世界龍頭機(jī)器制造商用3D印刷術(shù)進(jìn)行了一次格外成功的應(yīng)用
ULTRASOUND scanners are used for tasks as diverse as examining unborn babies and searching for cracks in the fabric of aircraft.
超聲波掃描器的應(yīng)用領(lǐng)域很廣，小到用于檢查胎兒，大到飛行器機(jī)體瑕疵檢測等。
They work by sending out pulses of high-frequency sound and then interpreting the reflections as images.
機(jī)理過程是，通過發(fā)射高頻聲波脈沖信號對反射信號進(jìn)行成像解讀。
To do all this, though, you need a device called a transducer.
但完成該過程，你不能缺少一臺叫做‘壓電式換能器'的設(shè)備。
Transducers are made from arrays of tiny piezoelectric structures that convert electrical signals into ultrasound waves by vibrating at an appropriate frequency.
壓電式換能器是由具有‘壓電'效應(yīng)的一系列敏感元件機(jī)構(gòu)組成。敏感元件機(jī)構(gòu)通過‘定頻'震蕩將電信號轉(zhuǎn)換成超聲波。
Their shape focuses the waves so that they penetrate the object being scanned.
機(jī)構(gòu)的特定外形可聚焦超聲波，對被掃描的物體產(chǎn)生穿透作用。
The waves are then reflected back from areas where there is a change in density and on their return the transducer works in reverse, producing a signal which the scanner can process into a digital image.
超聲波會(huì)從密度發(fā)生變化的介質(zhì)反射回來，這時(shí)壓電式換能器會(huì)反向操作產(chǎn)生信號，再經(jīng)過掃描器的處理，最后進(jìn)行數(shù)字成像。
To make a transducer by painstakingly micro-machining a brittle block of ceramic material can take many hours of work, though.
壓電式換能器需要用到陶瓷材料，而精密地加工一塊精細(xì)的陶瓷材料就要耗費(fèi)幾個(gè)小時(shí)的工作時(shí)間。
As a result, even as the size and cost of the console that controls the scanner has fallen with advances in microelectronics (some are now small enough to fit in a doctor's pocket and cost a few hundred dollars), the cost of making the probe itself remains stubbornly high—as much as ten times that of the console.
隨著微電子領(lǐng)域中，技術(shù)的突飛猛進(jìn)，控制掃描儀的電路板無論從體積還有成本都有很大程度的優(yōu)化變小和降低。有些電路板小到可以裝進(jìn)醫(yī)生口袋里面，成本也不過幾百美元的價(jià)格。而制作換能器探頭的成本卻一直居高不下，跟電路板相比，探頭的制作成本大概是一塊電路板的10倍左右。
At least, it does if you use traditional "subtractive" manufacturing techniques like cutting and drilling.
即使不考慮體積及成本的情況下，傳統(tǒng)的‘對比相減式'加工流程技術(shù)也能完成這些工作，比如切割，機(jī)鉆等。
However GE, a large American conglomerate, is now proposing to make ultrasound transducers by "additive" manufacturing—or three-dimensional printing, as it is also known.
而GE作為美國的一個(gè)龐大的企業(yè)集團(tuán)正考慮采用‘對比添加式'的加工流程（或者又稱大家所熟悉的‘3D印刷'）來加工超聲波壓電式換能器。
A new laboratory at the firm's research centre in Niskayuna, New York, is taking a hard-headed look at the technique, which some see as a fad and others as the future,
GE在紐約Niskayuna地區(qū)的研發(fā)中心新成立了一個(gè)實(shí)驗(yàn)室，目前該實(shí)驗(yàn)室正本著理性實(shí)際的態(tài)度（非一時(shí)狂熱）對該項(xiàng)技術(shù)進(jìn)行研發(fā)，力圖找到哪些產(chǎn)品用‘對比添加式'而非‘對比相減式'的技術(shù)流程加工生產(chǎn)更加適合。一些人認(rèn)為，對該項(xiàng)技術(shù)的研發(fā)只不過是一時(shí)狂熱。
and working out which products might be made more efficiently by addition rather than subtraction.
還有一些人聲稱，目前的時(shí)機(jī)并不成熟，對該項(xiàng)技術(shù)的研發(fā)僅僅具有‘將來時(shí)'的意義罷了。
Ultrasound transducers were an early pick both because of the complicated geometry needed to focus the sound waves and because ceramics are harder than metals to cut and drill accurately.
最初選擇超聲波壓電式換能器來作為‘3D印刷術(shù)'的對象原因有兩點(diǎn)。一是該換能器用來聚焦聲波的機(jī)體外形非常復(fù)雜，二是它用到的陶瓷材料比金屬的硬度要高很多，很難進(jìn)行精準(zhǔn)地切割和機(jī)鉆。
But they are easy to print.
而用‘3D印刷術(shù)'卻很容易解決這兩個(gè)難題。
The GE process for making a transducer begins by spreading onto the print table a thin layer of ceramic slurry containing a light-sensitive polymer.
GE對加工換能器的方法是首先在印刷臺上撒上薄薄的一層陶瓷粘土，其中混入一種光敏聚合體。
This layer is exposed to ultraviolet light through a mask that represents the required pattern.
然后用紫外線通過露光模板的光孔照射到印刷臺的粘土層，以此塑造出需要的模型圖案。
Wherever the light falls on the polymer it causes it to solidify, binding the particles in the slurry together.
光敏聚合體一經(jīng)被紫外線照射就會(huì)立即變得堅(jiān)硬，粘土中的粒子隨即凝結(jié)固化。
The print table is then lowered by a fraction of a millimetre and the process repeated, with a different mask if required.
接下來，印刷臺會(huì)以不超過一毫米的距離向下位移，然后重復(fù)整個(gè)上面這一過程，如果有必要，需要重新更換一個(gè)新的露光模板。
And so on. Once finished, the solidified shape is cleaned of residual slurry and heated in a furnace to sinter the ceramic particles together.
以此反復(fù)處理直到整個(gè)過程結(jié)束，再進(jìn)行清理成模上的殘余粘土，最后把成模放入熔爐，以低于熔點(diǎn)的溫度進(jìn)行焙燒，最終完成陶瓷粒子的凝固收縮聚合。
More work will be needed to turn the process into a production-ready system.
該處理流程在具有批量生產(chǎn)體系能力之前，還需要做很多的工作。
But Prabhjot Singh, who leads the project, hopes that it will be possible to use it to make not just cheaper ultrasound probes, but also more sensitive ones that can show greater detail.
但項(xiàng)目負(fù)責(zé)人Prabhjot Singh表示，希望不僅僅制造出成本相對低廉的超聲波探頭，最好探頭的靈敏性也會(huì)更高，這樣可以讓我們通過成像看到更加細(xì)節(jié)化的信息。
Although researchers have had new transducer designs in mind for years, it has been impractical to construct them subtractively. Additive manufacturing could change that.
多年以來，壓電式換能器的研究者們一直都有新型設(shè)計(jì)的想法，但應(yīng)用‘對比相減式'的加工流程實(shí)際上很難能把這樣的構(gòu)想變?yōu)楝F(xiàn)實(shí)，而‘對比添加式'很可能會(huì)使這種困頓得到改善。
The new laboratory will look at other forms of additive manufacturing, too.
GE的新實(shí)驗(yàn)室還將研究其它‘對比添加式'的加工流程。
Some 3D printers spread metal powders on the print table and sinter the pattern with lasers or electron beams, rather than using masks.
比如一些3D印刷機(jī)在印刷臺鋪撒金屬粉末之后，采用露光模板以外的激光或電子束方式進(jìn)行熱凝處理來產(chǎn)生樣模。
Others deposit thin filaments of polymer in order to build structures up.
其它流程，如混入聚合體熱敏細(xì)絲通過自加固原理進(jìn)行聚合以產(chǎn)生成模。
GE is interested in how the technology could be used right across the firm's businesses, from aerospace to power generation and consumer products, according to Luana Iorio, head of manufacturing technologies at GE Global Research.
GE全球研發(fā)中心‘制造技術(shù)中心'主任Luana Iorio指出，GE旨在為各種商業(yè)形式，包括象航空航天、能源及消費(fèi)產(chǎn)品等領(lǐng)域提供令人滿意的‘3D印刷技術(shù)'。
The gains include less waste and the ability to make bespoke parts more easily.
這種技術(shù)的獲益在于節(jié)約耗材和使第三方定制個(gè)性化零部件變得更加容易。
But one of the most compelling advantages is freeing designers from the constraints of traditional production.
但最無可爭辯的優(yōu)勢之一是讓設(shè)計(jì)者從傳統(tǒng)工藝的桎梏中解脫出來。
Those constraints include having to design things not in their optimal shape but to be machined, often as a series of pieces.
這些限制包括，設(shè)計(jì)者不得不用多個(gè)零部件去實(shí)現(xiàn)一個(gè)功能，不能從最優(yōu)化的外形尺寸來設(shè)計(jì)產(chǎn)品。
Additive manufacturing can combine parts into a single item, so less assembly is needed. That can also save weight—a particular advantage in aerospace.
‘對比添加式'可以整合零部件，避免了一些繁瑣的機(jī)械組裝過程，同時(shí)減輕了重量，這點(diǎn)對航空航天領(lǐng)域尤為有利。
These new production opportunities mean manufacturers, big and small, are about to become a lot more inventive.
在這種新的生產(chǎn)有利背景下，意味著制造商們，無論規(guī)模大小，都將變得更加具有創(chuàng)造性。
