CR4® - The Engineer's Place for News and Discussion®



Metals & Alloys

The Metals & Alloys Blog is the place for conversation and discussion about ferrous and nonferrous metals, metalworking processes, and specialty alloys. Here, you'll find everything from application ideas, to news and industry trends, to hot topics and cutting edge innovations.

Mini Motor Made Only of Liquid Metal

Posted March 18, 2015 3:55 PM by HUSH

Last week there were some dubious media reports that scientists were a step closer to T-1000 technology. Being the avid Terminator fan that I am, I immersed myself in coverage of this development.

Of course, I was disappointed when headlines gave way to a story about liquid galinstan droplets that use aluminum flakes as fuel to create propulsion when submerged in sodium hydroxide. There were zero reports of bodybuilders on motorcycles, time travel, or a biological vs. technological war, all of which might spice things up a bit.

Instead, the liquid gallium droplets were being compared to T-1000s because its structure allows it to navigate constricted passages and confined spaces, similar to how the T-1000 was able to liquefy its "mimetic polyalloy" to slip under closed doors, or as in this scene, shape shift from dispersed puddles into a well-sculpted Robert Patrick.


Galinstan is an alloy of gallium, indium and tin with a melting point of -2° F. Placing a droplet of galinstan in a solution of sodium hydroxide and then feeding the galinstan drop with a flake of aluminum provides locomotion for the liquid alloy droplet. A charge differential is created across the droplet to provide spin (known as electrowetting), while the reaction between aluminum and the solution creates hydrogen bubbles. The spinning droplet uses the bubbles for traction, and the result is a single material engine.

What does this mean for practical applications? First, micro- and nano-sized pumps can be developed without an external power supply or mechanical components. Not only can complicated pump components be eliminated, but a pump could be complete enclosed. Currently, the galinstan droplets are powered for 30 minutes by a single flake of aluminum, but it's not hard to imagine technological or refueling improvements that could create a permanent motor.

Experiments have showed that the droplet can navigate obstacles and even elongate and change shapes to get through environments. For this reason, there is hope that these materials could be harnessed to deliver materials to pipes as well as blood vessels. Now to create a Robert Patrick-esque Terminator, researchers demonstrated that the galinstan balls can create complex shapes in the presence of an electrical field. As of now liquid galinstan has only a few uses: as a replacement for mercury in thermometers or as a thermal conductor or coolant.

Yet it's also not going to be coagulating into robots or anything else. Galinstan droplets are a long way from being useful at all, let alone from becoming a science fiction threat. Instead, creating threats from pools of liquid materials comes from the world of 3D printing. Peachy Printer and continuous liquid interface production are two example technologies that are much closer to delivering T-1000s. That's not to discount the reveal of the self-propelled galinstan droplet, only to note that we're not closer to Skynet doomsday than the last time I wrote about it.

Add a comment

Liquid Metal for iPhone? "Not Yet"

Posted February 27, 2014 12:01 PM by Engineering360 eNewsletter

Apple Holic blogger Jonny Evans writes that the inventor of LiquidMetal, Atakan Peker, says the resilient, amorphous metallic glass alloy is "years away" from use in such devices as the next generation iPhone. Peker adds the manufacturing process and "application development" still need to be perfected. Peker also notes that Apple would have to plunk in about half a billion dollars in manufacturing tools to take full advantage of the material's technology beyond small components - such as SIM card ejectors - into full-blown device cases and structures, which are strong and scratch and corrosion resistant.


Editor's Note: This news brief was brought to you by the Metals & Alloys News eNewsletter. Subscribe today to have content like this delivered to your inbox.

Add a comment

Canada Eliminated the Penny; Is Cash Next?

Posted February 13, 2013 2:58 PM by HUSH

In what may have been international news last week, the Royal Canadian Mint officially struck the penny from distribution. Of course, that doesn't make the penny obsolete; it remains legal tender. Cash transactions are rounded to the nearest nickel and non-cash purchases are still designated in one-cent increments. The Canadian penny will exist in perpetuity, or at least until the RCM can collect and melt the 35 billion pennies in circulation.

The argument exists that the American taxpayer would see a similar benefit if the American penny is eliminated. Between material and production costs, it costs the U.S Mint two pennies to make one penny, and if melted down to its raw materials, one penny is worth about two and a half pennies. Just like in Canada, American citizens find the penny mostly useless. Similarly, Britain's pound sterling relies on the penny for denominations of 1/100 of a pound; the cost to make 1p is 1.5 pence. Pennies are often left at cash registers or on the sidewalk, hoarded away by the hundreds, or exchanged for larger denominations. Wise but rare is the consumer who completely utilizes a coin purse.

As Abba sings: "There never seems to be a single penny left for me; That's too-ooo baddd!" In fact, money is a recurring muse for many musicians, ranging from classic rock (Pink Floyd's 'Money') to rap (Puffy's 'All About the Benjamins'). Yet these lyrics only speak to the physical representation of money, not its theoretical concept. As the world moves into international and alternative currencies, rappers may lose some street cred if they start rhyming about digital transactions and pennies.

So where is the penny -- and currency as a whole -- headed? Before we go further, let's review the dollar system with the graphic on the right. I'll note that the only significant difference between the American and Canadian dollar systems is Canada's two dollar coin, or 'toonie', another nuance of Canadian currency. And for a review of the current minting process, here's a video of the stamping process used to manufacture coins.

While technology that supports cash flow rapidly changes, the institution of money does not. Barter and item trading is the oldest means of exchanging goods, but by 2,000 B.C. receipts for items in storage began to serve as a means for representing items in trade. These receipts were irregular metal ingots, with the commodity and its value represented by the grade of the metal and any inscribed symbols. The items that represent exchangeable goods and services vary by culture. Native Africans relied on ivory, livestock, beads, and weapons, while Native Americans sold Manhattan to the Dutch for 60 guilders (about $24 USD), a currency for which they had no use. The first coins were pressed in the Kingdom of Lydia, sometime around the 12th Century B.C. Paper money first appeared in the 7th Century in China as a receipt for a sum of coins. Around the same time, economists and merchants in the Middle East began establishing credit, cheques, banking accounts, trusts and loans.

Of course the ideology behind all of this currency was that it was a bearer slip, and it could be redeemed at government reserves for an equal amount of gold and silver (or in earlier times, grain and livestock). There were significant disadvantages to this system, as governments could print more currency than what they had in stock, diminishing the return value. In the early 20th Century, banks and reserves continued to keep a precious metal standard to back up banknotes, but eventually decided it could better manage financial crises with fiat money, or money that has no intrinsic value. Representative of the U.S.'s conservative attitude regarding currency, it was one of the last nations to eliminate its gold standard, which it did in 1971.

This brings us to recent attempts to revive the gold standard. From 1998 to 2009, Liberty Services, began creating Liberty Dollars, a private currency redeemable from the company for amounts of precious metals. Despite U.S Treasury officials declaring the tender legal, the assets of the company were seized and the creator was later arrested and convicted on several charges.

Many other alternative currencies exist today. The most widely used would be the bitcoin, a digital currency based on an open source protocol. No bank or central reserve can regulate this currency. This currency is accepted across international websites and is held in the owner's encrypted file wallet. They are transferred using bitcoin keys, a string of numbers and letters exceeding 30 characters. Websites from Wikileaks to Domino's have begun accepting bitcoins, which can be exchanged for $16--$25 USD, depending on rates. Since bitcoins can be divvied into 100,000,000 satoyoshis it can be broken to better meet purchase prices. This is essential since there is a hard cap on how many bitcoins will be created; by 2140, all 21 million bitcoins will have been generated and the value of a full bitcoin will be much higher. Its open source and peer-to-peer nature assure of its adaptability, but many remain skeptical of the bitcoin's real purchase power.

In the recent worldwide economic turmoil, many communities have attempted to insulate themselves from a volatile economy by creating local currency. Typically, the currency is exchanged at a one-to-one rate and the local currency is accepted a number of community businesses. This fosters local business and in instances where businesses agree to return the local currency as a depreciated rate, can be used to fund community projects. Recent examples include the Toronto dollar and the BerkShare.

Contrasting the recidivism back to the gold standard, some companies are attempting to eliminate physical money altogether. Square is known as the company who created the card swiper for smartphones, but their latest idea eliminates cards and cash altogether. Their app, called Square Wallet, allows users to pay just by saying their name. After creating a login and linking a financial account, the app recommend nearby merchants who accept the Square Wallet, and after saying your name and accessing the app, your photo will appear on the cash register. Transactions take seconds. Google and PayPal have launched similar services, but Square is considered the easiest to use. Square can also has options for tipping and withholding loyalty cards. In a similar vein, Twitpay has become a chance to conduct transactions simply by linking a PayPal with a Twitter account.

Will electronic transactions replace cash in our lifetimes? Seemingly not. In the 1950s credit cards were predicted to be the end of cash, but today 8 of 10 transactions still require the physical exchange of bills and coins. Cash's 2,700 years of existence is owed to its simple technology and high gratification. Anyone can possess cash--you don't need a bank account--and futurist Dr. Michio Kaku explains it as the Cave Man Principle: when technology (high tech) clashes with primitive desires (high touch), people are more content with a physical interaction.

A sentimental argument is used to keep the American penny in circulation as well: a 2012 poll found 67% of Americans favored keeping the penny despite its limited power. It probably helps that one of the country's most popular presidents, Abraham Lincoln, graces the obverse. Charities also depend on pennies for thousands of dollars of contributions. It would also increase the demand for nickels, which cost 11 cents to make, and thereby generate a bigger manufacturing deficit.

When the half-penny was eliminated from American currency, it had more purchasing power than a dime today. Yet the U.S. government in 1857 thought it was prudent move. If this were a private company looking to maximize profitability, I can guarantee the penny would have been discontinued upon its first proposal in 1989. Of course the mint could use a lesser grade metal (pennies are mostly zinc), but they seem resistant to that idea.

I personally feel we could get rid of the penny. It's not like rappers are singing about pennies, and especially if it can spare me from hearing Christopher Walken's autotuned "Pennies from Heaven." What do you think?

Resources

(Image credit: Wikipedia; The Awl; Reid Gold; World Changing; Tom McConnon; Coffee Shop Investor; USA Coinbook)

Wikipedia - Bitcoin; Alternative currency; Gold standard; Penny debate in the United States

The Next Web - The Future of Money...

The New Yorker - Penny Dreadful

World Future Society - The Future of Money in a Mobi-Digital World

10 comments; last comment on 02/17/2013
View/add comments

Fun With Magnets

Posted November 12, 2012 9:12 AM by yamdankee

Buckyballs®, Zen Magnets®, Neocubes™, nanodots®, no matter which brand you prefer or fight for, they are all very cool and quite popular desk toys. Made from rare earth magnets, they come in a variety of shapes, sizes, and colors, making your creativity the only limit. People have made all kinds of interesting sculptures, designs, and even functioning machines. Here are examples of some really cool concepts:


And some interesting machines:

Spinning Machine: http://youtu.be/fnWIUw0txzo

Making a sphere spin vertically (not actually Buckyballs® but pretty neat): http://www.youtube.com/watch?v=wdgzU_84VMg&feature=related

And, my favorite because I could actually build it (see below), a tiny motor: http://www.youtube.com/watch?v=mJWJXaWz94k

And even a solar powered one: http://www.youtube.com/watch?v=oGFNn6OTVWg


Here's my attempt at the motor:

Though these little things are so fun, the CPSC (Consumer Product Safety Commission) has recently put a ban on the Buckyballs® and Buckycubes®. Over half a billion magnets were sold, and less than two dozen incidents have ever been reported. It doesn't look like they'll be around forever, at least for Buckyballs®, so get them while you still can!

Already have some? Post your creations!

(Sources: http://www.thepaperplace.ca/wp/2010/12/20/buckyballs-taking-toronto-by-storm/, http://www.zenmagnets.com/blog/category/active/, http://www.getbuckyballs.com)

1 comments; last comment on 11/13/2012
View/add comments

Do We Have to Grin and Bear the Rare Earth Supply Situation?

Posted January 17, 2012 9:45 AM

With China's grip on the rare-earth market, do you think an alternative electric motor technology can be perfected that side steps the need (and costs) for the metals in motors?

The preceding article is a "sneak peek" from Metals & Alloys, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Metals & Alloys today.

3 comments; last comment on 03/02/2014
View/add comments


Previous in Blog: Are You Doing More Metal Processing Online?  
Show all Blog Entries in this Blog

Advertisement