IN THE PIPELINE: Whispering Windows, Whale-Friendly Sonar
AMES, Iowa -- Windows and walls that radiate sound. A church pew that lets a deaf person "hear" the service. Sonar that doesn't beach whales.
That's just for starters when the managers at Etrema Products, a small, closely held high-tech company, talk about the possibilities - indeed, the emerging realities - of their "magic crystals."
Those crystals are so proprietary that Etrema's headquarters, in the Iowa State University Research Park in this Midwestern college town, is under tight security.
Etrema's primary product is Terfenol-D, an alloy of rare-earth elements that make for what company officials call a "smart material" - smart because it changes shape in a magnetic field as it converts electrical energy into mechanical power, and vice versa. In technical terms, that makes Terfenol a solid-state transducer and its process magnetostriction.
Terfenol's ability to change shape 10,000 times a second, and more, is being harnessed in myriad ways, from applications for machine shops and Alpine tunnels to department stores and pig farms.
A product laymen may encounter soon is called "Whispering Windows," which turns any solid, flat surface - be it panes of glass, plasterboard walls or wooden tabletops - into stereophonic speakers from which sound emanates everywhere with equal volume and clarity.
The seeming acoustical trickery involves a piece of Terfenol half the length of a matchstick that is surrounded by a coil and sheathed in a chrome case the size of a hockey puck. The device amplifies sound waves that can turn a retailer's window into an unseen pitchman or any room of a house into a musical womb.
Researchers found that such an installation at a Peter Jones department store in London "turned 49% more heads" than a normal, silent display window, says Etrema general manager Michael Conley.
Such data likely will be used in marketing the $1,500 kit. So far only two U.S. customers have installed the devices - a restaurant and a liquor store in Ankeny, Iowa, a few miles down the road from Ames. But Etrema hopes to hook a national retailer interested in differentiating its outlets from the competition. The company also is talking to homebuilders.
Another acoustical application is in test in an Iowa church, where a pew has been fitted with Etrema acoustic drivers so that a hearing-impaired worshipper could "hear" the service through his or her tailbone.
Soundbug, a device aimed at the consumer market, employs similar technology. About the size of a computer mouse, it plugs into the headphones socket of a laptop or portable CD player and attaches via suction cup to a table or similar surface, turning it literally into a sounding board.
Etrema believes the item will be popular with business people making presentations at sites not equipped with standard audio/visual capability. A $20 price tag is contemplated for Soundbug, which would get Terfenol-D into the consumer mainstream.
Terfenol-D is an acronym. The TER is for terbium, one of its rare-earth lanthanides, FE is the periodic symbol for iron, NOL is for the Naval Ordnance Labs which discovered it and the D is for dysprosium, another lanthanide.
The alloy's crystals are grown in two nine-foot chambers. Its metals are heated until molten, then flash frozen. The resulting rods can be machined into a multitude of shapes, or converted to powder or thin-film forms. At full capacity Etrema can produce about 200 pounds of Terfenol-D a day.
The Navy developed Terfenol in the 1940s in its search for ways to improve sonar. At the time the underwater detection system was based on piezoceramics technology. But the Navy wanted a sonar with greater bandwidth and reliability.
Etrema officials say little about Terfenol's uses by the military, other than the Pentagon accounts for about 40% of the company's $10 million in annual revenue. But they acknowledge that Terfenol-D is being used in sonar designed for relatively shallow coastal waters, where today's submarine threats are thought the greatest.
The shallower depth increases the risk that the "Ping!" transmitted by a ship's sonar will divulge its location and make it vulnerable to attack. To preclude that possibility, Terfenol is being fitted into sonar that can be towed by a remote-operated vehicle hundreds of miles from a mother ship.
Sound waves emitted by the new sonar also are thought to be less harmful to sea life, since they needn't be nearly as strong. Some environmentalists have long contended that sonar is partly responsible for the phenomenon of whales beaching themselves as they apparently flee its frequencies.
The ultrasonic waves Terfenol-D can create also are being applied to an array of industrial challenges. Carmaker Ford Motor Co. (F) is heading an $8.9 million effort using those waves to develop a welding tool that could produce aluminum vehicles. Less weight, of course, means better fuel economy. Other Ford researchers are seeing whether fuel injectors fitted with bits of Terfenol result in a more efficient gasoline burn.
In road construction Terfenol is being employed in mountain tunneling, helping drills detect granite sooner than traditional acoustics, making it easier and cheaper to reroute roadways.
Terfenol's molecular movement can be precisely calibrated and controlled. So equipment maker Briggs & Stratton Corp. (BGG) harnesses those capabilities to lathes to turn out precision-machined metallic pistons much more rapidly than traditional technology can.
An Etrema sister company, Ag Waste Recovery Systems, uses Terfenol to recycle hog wastes on farms. The waste is pumped through a chamber, where ultrasonic waves rupture the cell walls of bacteria - killing them and removing most of their odor. The material can then be dried into a pathogen-free fertilizer.
"It's huge," says Etrema President Bill Flowers of Terfenol's potential. "The biggest problem we have around here is staying focused on one thing."
Investors in Edge Technologies, Etrema's parent, include some Midwestern heavyweights: Principal Financial Group (PFG), the MidAmerican Energy unit of Berkshire Hathaway Inc. (BRKA BRKB), the Pioneer Hi-Bred unit of DuPont Co. (DD), American Republic Insurance Co., and Ruan Cos., a Des Moines transportation and insurance firm.
While Etrema considers itself the world's leading producer of Terfenol, the Chinese are would-be competitors.
Today most of the world's supply of terbium and dysprosium come from China. Etrema officials say the Chinese make and sell Terfenol-D, but are barred from doing so in numerous industrialized countries where Etrema has filed patents.
Company executives realize that Terfenol-D's life expectancy as one of the world's "smartest" materials is limited. "We're probably five to seven years ahead" of whatever will eventually replace it, says President Flowers . "We're working" on its possible successor, he adds - "but we can't tell you about it. It's secret."
会说话的窗户
窗户和墙壁可以传播声音，教堂的长椅可使聋人"听"到礼拜仪式，声纳装置不会使鲸鱼搁浅。
当Etrema Products公司的管理人士谈到公司一种神奇晶体的潜在应用前景时表示，上面提到的仅仅是一些最初级的应用。Etrema Products是一家小型高科技非上市公司。确实，该晶体已经运用到实际应用当中。
公司的这些晶体非常宝贵，为其特有的专利产品。为此，公司位于艾奥瓦州立大学科技园(Iowa State University Research Park)的总部采取了"壁垒森严"的保安措施。
Etrema的主要产品是铽镝铁磁致伸缩材料(Terfenol-D)，一种由稀土元素构成的合金材料。这种材料被公司管理人士称为智能材料，因为它能够在磁场作用下改变形状，还能实现电能与机械能的相互转换。用技术术语表示，铽镝铁磁致伸缩材料是一种固态能量转换器，并可处理磁弹性。 铽镝铁磁致伸缩材料可以在一秒中变形10,000次或更多，用途十分广泛，可用于机器加工车间、阿尔卑斯山的隧道、百货商店或饲养场。
其中有一个被称为"会讲话的窗户"的产品。该产品可将任何固体的平面－－不论是玻璃、石膏板墙面，还是木制桌面－－转变为立体声音箱，其所发出的声音具有相等的音量和清晰度。
产生这一魔幻效果的东西就是仅有火柴棒一半长的一段铽镝铁磁致伸缩材料，这段材料被放置在一段螺旋管中，然后在放在一个冰球大小的铬制盒子里。这个装置可放大声波，使一个商店的橱窗变成一个隐形的产品推销员，或者使房子的某个房间成为八音盒。 Etrema的总经理麦克尔?康雷(Michael Conley)说，研究人员发现，在伦敦Peter Jones百货商店的橱窗安装这一装置后，能够比普通不发声的橱窗多吸引49%的顾客。
当推销这一价值1,500美元的装置时，这些资料可能会起到帮助。目前仅有两家美国客户购买了这个产品：位于离爱姆斯几英里远的安克尼市的一家餐馆和一家酒吧。而Etrema希望一个全国性零售商也成为其客户，这家零售商希望其零售店的装潢别具一格。此外，公司还正在与一些住宅建筑商进行洽谈。
铽镝铁磁致伸缩材料另一个在声学方面的用途正在艾奥瓦州的一个教堂进行试验。该教堂的一个长椅中安装了Etrema的声学装置，这样，患有耳疾的教徒可以通过身体"听"到礼拜仪式。
Soundbug也采用了类似技术。该装置为鼠标大小，可以插入笔记本电脑或CD机的耳机插孔，并通过吸盘吸附在桌面或其他物体的表面上，使其成为一个扬声器。
Etrema相信，这一装置将受那些在没有标准音响设备场地做讲座的商务人士的欢迎。公司经过深思熟虑将该产品的价格定为20美元，这将有助于铽镝铁磁致伸缩材料进入大众的主流生活。
铽镝铁磁致伸缩材料是在两个9英尺的冶炼室中形成的。其金属被加热至融化，然后被快速冷却。制成的材料棒可以加工成各种形状，或转变成粉末或薄膜。Etrema每天最多能生产200磅铽镝铁磁致伸缩材料。
美国海军上个世纪四十年代在改进声纳技术的研究中开发了这一材料。当时，水下导航系统是基于压电陶瓷技术。而海军需要带宽更大且更加可靠的声纳系统。
除了五角大楼的订单占该公司1,000万美元年收入的40%以外，Etrema管理人士很少谈及军方对这一材料的使用。 但他们承认，铽镝铁磁致伸缩材料被浅水声纳系统所采用，而当今普遍认为潜艇面临的最大威胁就来自于浅水海域。 当潜艇在浅水领域航行时，它发出的声纳更易使其暴露位置，遭受攻击的风险也随之上升。可以把铽镝铁磁致伸缩材料放置在声纳系统中，由远程控制装置拖曳使用，而母舰可停靠在几百英里外之处，这样就避免了被攻击的风险。
采用新材料的声纳系统所产生的声波被认为对海洋动物的危害更小，因为声波的音量不必很大。长期以来，一些环境保护者一直认为，声纳装置是导致鲸鱼搁浅的部分原因，因为鲸鱼显然是为了躲避声纳所发出的声波而冲上海滩的。
这种新材料可产生的超声波还被应用于其他工业领域。福特汽车(Ford Motor Co., F)投资了890万美元，正在进行一项研究，利用这种超声波开发一种焊接工具，来制造铝制汽车。汽车重量减轻了，当然会更省油。其他福特汽车研究人员正在研究，喷油器在安装了这种新材料后是否会使汽油燃烧更充分。
在道路建设方面，铽镝铁磁致伸缩材料正被运用于开凿山体隧道。它和传统的声学装置相比可以在钻探时更早地发现花岗岩，从而使重新设计路线的工作更加容易且成本更低。
铽镝铁磁致伸缩材料的分子运动可以被精确地确定和控制。设备制造商Briggs & Stratton Corp. (BGG)将这些特性运用于车床，从而能较传统技术更快地生产出经过精密机加工的金属活塞。
Etrema的姊妹公司Ag Waste Recovery Systems将铽镝铁磁致伸缩材料运用于农场上猪粪的循环利用。超声波可以破坏粪便中细菌的细胞壁，从而杀死细菌并消除大部分异味。处理后的粪便在经干燥后即成为无菌肥料。
Etrema首席执行长比尔?佛劳尔斯(Bill Flowers)表示，这种新材料的用途太广了，公司现在最大的问题是将该材料集中用于某一方面。
Etrema母公司Edge Technologies的投资机构中包括了一些中西部地区的重量级公司。如，信安金融(Principal Financial Group Inc., PFG)，Berkshire Hathaway Inc. (BRKA BRKB)的子公司MidAmerican Energy，杜邦公司(DuPont Co., DD)的子公司Pioneer Hi-Bred，American Republic Insurance Co.，以及得梅因运输和保险公司Ruan Cos.。
尽管Etrema认为其是全球领先的铽镝铁磁致伸缩材料制造商，但中国将可能成为其有力的竞争者。
现在全球大部分铽和镝都来自中国。Etrema公司的管理人士称，中国制造并销售铽镝铁磁致伸缩材料，但不能在很多工业化国家开展业务，因为Etrema已在这些国家注册了专利。
公司管理层意识到，铽镝铁磁致伸缩材料作为世界上最神奇材料的寿命是有限的。公司首席执行长Flowers表示，大约再有5年到7年的时间就会出现新产品取代其位置。他还补充说，公司正在对这些更为先进的替代品进行研究。但关于新产品的情况他表示无可奉告，因为这是商业机密。
