Ambient Electromagnetic Energy Harnessed for Small Electronic Devices by Rick Robinson

Researchers have discovered a way to capture and harness energy transmitted by such sources as radio and television transmitters, cell phone networks and satellite communications systems. By scavenging this ambient energy from the air around us, the technique could provide a new way to power networks of wireless sensors, microprocessors and communications chips.

“There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it,” said Manos Tentzeris, a professor in the Georgia Tech School of Electrical and Computer Engineering who is leading the research. “We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability.”

Tentzeris and his team are using inkjet printers to combine sensors, antennas and energy-scavenging capabilities on paper or flexible polymers. The resulting self-powered wireless sensors could be used for chemical, biological, heat and stress sensing for defense and industry; radio-frequency identification (RFID) tagging for manufacturing and shipping, and monitoring tasks in many fields including communications and power usage.

A presentation on this energy-scavenging technology was scheduled for delivery July 6 at the IEEE Antennas and Propagation Symposium in Spokane, Wash. The discovery is based on research supported by multiple sponsors, including the National Science Foundation, the Federal Highway Administration and Japan’s New Energy and Industrial Technology Development Organization (NEDO).

Communications devices transmit energy in many different frequency ranges, or bands. The team’s scavenging devices can capture this energy, convert it from AC to DC, and then store it in capacitors and batteries. The scavenging technology can take advantage presently of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher.

Scavenging experiments utilizing TV bands have already yielded power amounting to hundreds of microwatts, and multi-band systems are expected to generate one milliwatt or more. That amount of power is enough to operate many small electronic devices, including a variety of sensors and microprocessors.

And by combining energy-scavenging technology with super-capacitors and cycled operation, the Georgia Tech team expects to power devices requiring above 50 milliwatts. In this approach, energy builds up in a battery-like super-capacitor and is utilized when the required power level is reached.

The researchers have already successfully operated a temperature sensor using electromagnetic energy captured from a television station that was half a kilometer distant. They are preparing another demonstration in which a microprocessor-based microcontroller would be activated simply by holding it in the air.

Exploiting a range of electromagnetic bands increases the dependability of energy-scavenging devices, explained Tentzeris, who is also a faculty researcher in the Georgia Electronic Design Center (GEDC) at Georgia Tech. If one frequency range fades temporarily due to usage variations, the system can still exploit other frequencies.

The scavenging device could be used by itself or in tandem with other generating technologies. For example, scavenged energy could assist a solar element to charge a battery during the day. At night, when solar cells don’t provide power, scavenged energy would continue to increase the battery charge or would prevent discharging.

Utilizing ambient electromagnetic energy could also provide a form of system backup. If a battery or a solar-collector/battery package failed completely, scavenged energy could allow the system to transmit a wireless distress signal while also potentially maintaining critical functionalities.

The researchers are utilizing inkjet technology to print these energy-scavenging devices on paper or flexible paper-like polymers — a technique they already using to produce sensors and antennas. The result would be paper-based wireless sensors that are self-powered, low-cost and able to function independently almost anywhere.

To print electrical components and circuits, the Georgia Tech researchers use a standard-materials inkjet printer. However, they add what Tentzeris calls “a unique in-house recipe” containing silver nanoparticles and/or other nanoparticles in an emulsion. This approach enables the team to print not only RF components and circuits, but also novel sensing devices based on such nanomaterials as carbon nanotubes.

When Tentzeris and his research group began inkjet printing of antennas in 2006, the paper-based circuits only functioned at frequencies of 100 or 200 MHz, recalled Rushi Vyas, a graduate student who is working with Tentzeris and graduate student Vasileios Lakafosis on several projects.

“We can now print circuits that are capable of functioning at up to 15 GHz — 60 GHz if we print on a polymer,” Vyas said. “So we have seen a frequency operation improvement of two orders of magnitude.”

The researchers believe that self-powered, wireless paper-based sensors will soon be widely available at very low cost. The resulting proliferation of autonomous, inexpensive sensors could be used for applications that include:

• Airport security: Airports have both multiple security concerns and vast amounts of available ambient energy from radar and communications sources. These dual factors make them a natural environment for large numbers of wireless sensors capable of detecting potential threats such as explosives or smuggled nuclear material.

• Energy savings: Self-powered wireless sensing devices placed throughout a home could provide continuous monitoring of temperature and humidity conditions, leading to highly significant savings on heating and air-conditioning costs. And unlike many of today’s sensing devices, environmentally friendly paper-based sensors would degrade quickly in landfills.

• Structural integrity: Paper or polymer-based sensors could be placed throughout various types of structures to monitor stress. Self-powered sensors on buildings, bridges or aircraft could quietly watch for problems, perhaps for many years, and then transmit a signal when they detected an unusual condition.

• Food and perishable-material storage and quality monitoring: Inexpensive sensors on foods could scan for chemicals that indicate spoilage and send out an early warning if they encountered problems.

• Wearable bio-monitoring devices: This emerging wireless technology could become widely used for autonomous observation of patient medical issues.

Nano-research opens way to everlasting battery from RMIT University and RMIT Microplatforms Research Group

In a crucial step towards the development of self-powering portable electronics, RMIT University researchers have for the first time characterised the ability of piezoelectric thin films to turn mechanical pressure into electricity.

The pioneering result has been published in the leading materials science journal, Advanced Functional Materials.

Lead co-author Dr Madhu Bhaskaran said the research combined the potential of piezoelectrics – materials capable of converting pressure into electrical energy – and the cornerstone of microchip manufacturing, thin film technology.

“The power of piezoelectrics could be integrated into running shoes to charge mobile phones, enable laptops to be powered through typing or even used to convert blood pressure into a power source for pacemakers – essentially creating an everlasting battery,” Dr Bhaskaran said.

“The concept of energy harvesting using piezoelectric nanomaterials has been demonstrated but the realisation of these structures can be complex and they are poorly suited to mass fabrication.

“Our study focused on thin film coatings because we believe they hold the only practical possibility of integrating piezoelectrics into existing electronic technology.”

The Australian Research Council-funded study assessed the energy generation capabilities of piezoelectric thin films at the nanoscale, for the first time precisely measuring the level of electrical voltage and current – and therefore, power – that could be generated.

Dr Bhaskaran co-authored the study with Dr Sharath Sriram, within RMIT’s Microplatforms Research Group, which is led by Professor Arnan Mitchell. The pair collaborated with Australian National University’s Dr Simon Ruffell on the research.

“With the drive for alternative energy solutions, we need to find more efficient ways to power microchips, which are the building blocks of everyday technology like the smarter phone or faster computer,” Dr Bhaskaran said.

“The next key challenge will be amplifying the electrical energy generated by the piezoelectric materials to enable them to be integrated into low-cost, compact structures.”

The study was published in Volume 21, Issue 12 of Advanced Functional Materials.

The Implications of Mexican Terrorists in Our Backyard by Sylvia Longmire

Mexican transnational criminal organizations (TCOs), more commonly known as drug traffickers or cartels, sure know how to act like terrorists. They’re cutting off people’s heads all over Mexico and hanging the decapitated corpses from bridges in plain view. They’re assassinating mayors, and kidnapping state governors who don’t want to play by the TCOs’ rules. They’re conducting massacres of innocent Mexicans riding public buses, then burying them in mass graves across northern Mexico.

Yet, these cruel and psychopathic thugs are considered mere criminals by both the US and Mexican governments.

In March 2011, US Representative Michael McCaul, R-Texas, introduced legislation that, if passed, would designate six Mexican TCOs as “foreign terrorist organizations.” McCaul said the TCOs are “using similar tactics to gain political and economic influence,” relying on “kidnappings, political assassinations, attacks on civilian and military targets, taking over cities and even putting up checkpoints in order to control territory and institutions.”

On April 7, 2011, the Dallas Morning News published an editorial supporting McCaul’s position.

“When drug cartel thugs order mass kidnappings, explode bombs, murder scores of public officials, behead victims or hang them from overpasses and post signs in border-area cities warning of more violence if they don’t get their way, that’s not mere drug trafficking. That’s terrorism,” the editorial stated.

Making this legal designation would open up new and interesting options for battling the TCOs on both sides of the border. Funding for federal, state and local law enforcement agencies working along the southwest border would open up. Programs for going after TCO funding and money laundering operations would increase. Tactics for going head-to-head with TCO members in the streets of Mexico might improve.

However, there are several important issues that would preclude either government from making such a drastic change in policy, and they’re not to be taken lightly.

First is the fact that the TCOs have no overt political, religious or ideological motivation for doing what they do; the violence is driven purely by the pursuit of monetary profit. This requirement is one of the common denominators of the various definitions of terrorism used by the US government.

Of course, an argument can be made that TCOs are killing politicians and coercing others under penalty of death to comply with their wishes, and that this is a form of government/political manipulation. However, this shouldn’t be confused with political ideology, as TCOs seek to manipulate the government only to facilitate their illegal activities, not actually take over the government.

Second, there’s the business of having thousands of Mexican terrorists and their contracted employees – gang members, straw purchasers, etc. – crawling all over Mexico and the United States. This is nothing new; members of Hezbollah have had a considerable presence in the United States for some time. They sell fake purses and fake cigarettes to raise money in order to fund their violent activities in the Middle East.

But Hezbollah in the United States has nowhere near the presence or reach of Mexican TCOs. What would it mean to, all of a sudden, have Mexican terrorists using our expansive highway network to transport drugs? Or renting homes in our middle-class neighborhoods to hold kidnapping-for-ransom victims? Or walking into a US gun shop to buy guns for use in terrorist operations?

Then the US government and law enforcement agencies would have to examine TCO support networks in the United States. Would US-based gang members who sell Mexican-origin drugs be prosecuted for supporting terrorism? What kind of scrutiny would millions of Mexican-Americans living in the United States start to face for their potential connections to these newly-designated terrorists?

The Mexican government hasn’t completely shied away from this concept. In 2010, the Mexican legislature passed a law that allowed for the treatment of TCOs as terrorists under certain circumstances, mostly for the purpose of increasing the duration of prison terms. However, in a justice system where only two percent of criminal cases are ever successfully prosecuted, this legislation has been largely meaningless.

Such a designation by the US government would also foster a whole host of political and diplomatic problems with the Mexican government. Secretary of State Hillary Clinton was publicly reprimanded for her use of the term “insurgency” when referring to Mexican TCOs and the drug war, largely over fear of how the Mexican government would react to such nomenclature. Mexico is already having a difficult time trying to put on a brave face for the international community, sending the message that President Felipe Calderón is winning the war against these criminals.

How would it appear to the world if Mexico became embroiled in a decidedly losing battle with six different terrorist groups, equated in theory to the likes of Al Qaeda and Hezbollah?

That is yet another issue regarding the legal consideration of TCOs as terrorists. Is it right to equate drug-dealing, kidnapping and extorting thugs to religious zealots who brought down the Twin Towers and have killed tens of thousands across the globe in the name of Allah?

Islamic terrorists commit a whole host of crimes, and many are involved in the drug trade as a way to raise money for their jihad. But putting TCOs and Islamic fundamentalists in the same bucket seems to take something away from the significance of acts like the attack on the US Marine Corps barracks in Beirut in 1983, or the Khobar Towers bombing in 1996.

Mexican TCOs have definitely moved beyond the label of mere criminals. They exhibit several aspects of terrorist groups, insurgencies throughout history and organized crime groups. A renaming at the federal government level is definitely in order because it could definitely result in more effective strategies and resource allocation to combat them.

However, going the route of labeling them as pure terrorists is inaccurate, currently too politically and diplomatically sensitive, and takes away from the significance of acts committed by traditional terrorist groups.

A retired Air Force captain and former Special Agent with the Air Force Office of Special Investigations, Homeland Security Today correspondent Sylvia Longmire worked as the Latin America desk officer analyzing issues in the US Southern Command area of responsibilty that might affect the security of deployed Air Force personnel. From Dec. 2005 through July 2009 she worked as an intelligence analyst for the California state fusion center and the California Emergency Management Agency’s situational awareness Unit, where she focused almost exclusively on Mexican drug trafficking organizations and southwest border violence issues. Her first book, “Cartel: The Coming Invasion of Mexico’s Drug Wars,” is scheduled to be published in Sept. To contact Sylvia, email her at: sylvia(at)longmireconsulting.com

Memorial Day 2011 by Oliver North

When I was a kid, we called May 30 “Decoration Day.” It was an occasion for Boy Scouts to be up before dawn and report, in uniform, to the American Legion hall. There, Cub Scouts would be paired with older Boy Scouts, organized into detachments of a dozen or so and issued bags of small American flags. The groups then “deployed” in station wagons and pickup trucks to local cemeteries and churchyards, where we placed Old Glory on every veteran’s grave. Later in the morning, there was a parade down Main Street, led by a color guard, the high-school band and ranks of veterans from World War I, World War II and the war of the moment, Korea. The Veterans of Foreign Wars sold red poppies to raise funds for the disabled. Politicians made speeches, and citizens prayed in public. It was a solemn annual event that taught us reverence for those who served and sacrificed for our country. It’s no longer so.

Begun as a local observance in the aftermath of the Civil War, the first national commemoration took place May 30, 1868, at the direction of Gen. John A. Logan, commander of the Grand Army of the Republic. Though his General Order No. 11 specified “strewing with flowers or otherwise decorating the graves of comrades who died in defense of their country during the late rebellion” — meaning only Union soldiers — those who tended the burial sites at Arlington, Va., Gettysburg, Pa., and Vicksburg, Miss., decided on their own to decorate the biers of both Union and Confederate war dead.

For five decades, the holiday remained essentially unchanged. But in 1919, as the bodies of young Americans were being returned to the U.S. from the battlefields of World War I, May 30 became a truly national event. It persisted as such until 1971, during Vietnam — the war America wanted to forget — when the Uniform Monday Holiday Act passed by Congress went into effect and turned Memorial Day into a “three-day weekend.” Since then, it’s become an occasion for appliance, mattress and auto sales, picnics, barbecues and auto races. Thankfully, there are some places besides Arlington National Cemetery where Memorial Day still is observed as a time to honor America’s war dead. Here in Triangle, Va., the Marines do it right.

Like all Marine Corps installations, every major structure at Quantico is named for a fallen fellow warrior. On May 13, hundreds of Marines and their families gathered to dedicate a new staff noncommissioned officer academy, named in honor of Sgt. Kenneth Conde Jr. Our Fox News’ “War Stories” team was embedded with his unit, 2nd Battalion, 4th Marines, in Ramadi, Iraq, during April 2004. Shortly after Sgt. Conde was wounded in action during a gunfight with enemy insurgents, I asked him why he refused to be medically evacuated. His response: “There is no other choice for a sergeant in the Marine Corps. You have to lead your Marines.”

Cpl. Jared McKenzie, one of Conde’s Marines, said of his sergeant: “He always led from the front and never asked us to do something he wouldn’t do.” Sgt. Conde was awarded a Bronze Star and a Purple Heart for his valor and wounds in that engagement. On July 1, just eight days after his 23rd birthday, he was killed by an improvised explosive device.

At the dedication ceremony, Conde’s battalion commander, Col. Paul Kennedy, described the young sergeant as “a courageous, inspiring leader.” The fallen Marine’s father, Kenneth Conde Sr., said: “I’m wearing my son’s combat boots. Though they fit, I could never fill them.”

Just down the road from Conde Hall is another testament to how the Marines honor America’s heroes. Quantico National Cemetery occupies 725 beautifully landscaped acres donated by the Marines to the Veterans Administration in 1977. This final resting place for more than 28,000 Americans who served in every branch of our armed forces is closely linked to some of the most crucial events in U.S. military history. The fledgling Continental Navy prepared to battle the British fleet here in 1775-76. During the Civil War, it was a blockade point and subsequently a logistics base during the bloody battle for Fredericksburg. In 1918, the Marines established a training base and an air station for units deploying to fight in World War I. Since 1941, Quantico has been the home of the Marines’ Officer Candidates School and The Basic School for all Marine officers. Today it is also home to the FBI and DEA academies.

On Memorial Day, an “Avenue of Honor” through Quantico National Cemetery is adorned with American flags. A “Memorial Pathway” displays monuments to Edson’s Raiders of WWII fame and recipients of the Purple Heart; memorials to the 1st, 4th and 6th Marine divisions; and a monument erected to America’s veterans by the commonwealth of Virginia.

This is also the final resting place for a close friend — and a reminder of present-day peril. On Feb. 17, 1988, U.S. Marine Col. William “Rich” Higgins was kidnapped in Beirut by Iranian-supported Hezbollah terrorists. They murdered him in July 1990. His remains were interred here in 1991. Rich Higgins’ gravesite is my Memorial Day reminder that the streets of heaven really are guarded by U.S. Marines. So are the streets of America.

Gaining muscle from mussels: High-strength CNT composite fibres by Marie-Claire Hermant

The exceptional mechanical properties of carbon nanotubes (CNT) have heralded it as the next generation super-strength fibre material. Researchers’ imaginations have run wild with the idea that these nano-sized carbon structures might allow us to build the worlds’ strongest cables, fibres and fabrics. From space elevators to bulletproof vests, CNTs find an immense field of application. Moreover, such materials could have a secondary functionality due to the ballistic electron transport possible through CNTs.

Whilst a vast development in the preparation of high-strength CNT-based fibres has taken place, many fibres still do not exceed strengths that have been achieved for hydrocarbon-based materials such as Dyneema and Kevlar. The majority of CNT fibres are prepared via a spinning process, either from solution or solid-state. Spun fibres undergo a twisting and post-spinning densification process to improve the mechanical properties. It is at this point that researchers from the KAIST Institute in South Korea have altered the preparation strategy, introducing an infiltration step to introduce polymeric cross-linking molecules. Mussel-inspired catechol-containing adhesive polymers suspended in methanol are absorbed into the twisted CNT-cable and cross-linked in a subsequent step.

The adhesive polymers investigated mimic proteins found in the adhesive foot of the marine mussel Mytilus edulis. These molecules undergo cross-linking, even in a marine environment, through chemical reactions between the catechol and amine groups in the proteins, as well as metal-coordination. Similar cross-linking reactions were performed on infiltrated CNT-cables; first through heat treatments, and secondly through iron-catechol coordination.

The strong binding of individual CNTs and the mussel-inspired matrix is easily seen when the cables are fractured and examined under an electron microscope. Most importantly, the tensile strength (strength to failure) of the treated fibres is increased by 500% over the CNT fibre alone. Even though the strength of a single CNT still dwarfs those reported here, the improvements observed when using the mussel-inspired adhesives are still commendable, especially when the scalability of fibre preparation is considered. With further modification of the cross-linker molecules, even higher strengths are likely possible.

Ryu et al. Adv. Mat. 2011, 23, 1971 – 1975 ; DOI: 10.1002/adma.201004228

3-D printers may someday allow labs to create replacement human organs by Bonnie Berkowitz

The machine looks like the offspring of an Erector Set and an inkjet printer.

The “ink” feels like applesauce and looks like icing. As nozzles expel the pearly material, layer by layer, you imagine the elaborate designs this device could make on gingerbread cookies.

But the goo is made of living cells, and the machine is “printing” a new body part.

These machines — they’re called three-dimensional printers — work very much like ordinary desktop printers. But instead of just putting down ink on paper, they stack up layers of living material to make 3-D shapes. The technology has been around for almost two decades, providing a shortcut for dentists, jewelers, machinists and even chocolatiers who want to make custom pieces without having to create molds.

In the early 2000s, scientists and doctors saw the potential to use this technology to construct living tissue, maybe even human organs. They called it 3-D bioprinting, and it is a red-hot branch of the burgeoning field of tissue engineering.

In laboratories all over the world, experts in chemistry, biology, medicine and engineering are working on many paths toward an audacious goal: to print a functioning human liver, kidney or heart using a patient’s own cells.

That’s right — new organs, to go. If they succeed, donor waiting lists could become a thing of the past.

Tony Atala, director of the Wake Forest Institute for Regenerative Medicine in North Carolina, envisions what he calls “the Dell computer model,” where a surgeon could order up “this hard drive, with this much memory …,” only he or she would be talking about specs for living tissue rather than electronics.

Bioprinting technology is years and possibly decades from producing such complex organs, but scientists have already printed skin and vertebral disks (the soft tissue that grows in the spine between the vertebrae) and put them into living bodies. So far, none of those bodies have been human, but a few types of printed replacement parts could be ready for human trials in two to five years.

“The possibilities for this kind of technology are limitless,” said Lawrence Bonassar, whose lab at Cornell University has printed vertebral tissue that tested well in mice. “Everyone has a mother or brother or uncle, aunt, grandmother who needs a meniscus or a kidney or whatever, and they want it tomorrow. … The promise is exciting.” But he warns that nothing is likely to be ready in time to help people who already need an organ. “The goal is not to squash that excitement, but to temper it with the reality of what the process is.”

The reality for now is that making such things as vertebral disks and knee cartilage, which largely just cushion bones, is far easier than constructing a complicated organ that filters waste, pumps blood or otherwise keeps a body alive.

Scientists say the biggest technical challenge is not making the organ itself, but replicating its intricate internal network of blood vessels, which nourishes it and provides it with oxygen.

Many tissue engineers believe the best bet for now may be printing only an organ’s largest connector vessels and giving those vessels’ cells time, space and the ideal environment in which to build the rest themselves; after that, the organ could be implanted.

The cells, after all, have been functioning within the body already in some capacity, either as part of the tissue that is being replaced or as stem cells in fat or bone marrow. (Donor stem cells could be used, but ideally cells would come directly from the patient.)

“The cells are actually the tissue engineers, so the people that do the work are just cheerleaders,” said Rocky Tuan, director of the Center for Cellular and Molecular Engineering at the University of Pittsburgh. “When we do tissue engineering, we are accelerating what the cells normally do. I tell people it’s assisted living, because we help the cells. We build all the houses and everything, and then we say, ‘Cells, come in and do your thing.’ ” If the cells do their thing correctly, the organ lives and grows just as the original once did.

Another huge challenge is common to much new research: lack of money.

“If the federal government created a ‘human organ project’ and wanted to make the kidney, I literally think it could happen in 10 years,” said chemical engineer Keith Murphy, co-founder of Organovo, a firm that makes and works with high-end bioprinters. But that would require a massive commitment of people, resources and billions of dollars, he said.

Once scientists get over the financial and technical hurdles of bioprinting, they will have to square the process with the Food and Drug Administration, which will have to decide how to regulate something that is not simply a device, a biological product or a drug, but potentially all three.

Before printed organs are implanted into people, bioprinting may be used in other ways. Murphy’s group is working on a project that will replicate tissue for testing the effects of medications, particularly cancer drugs. This could eliminate some of the drawn-out, trial-and-error process of trying a series of drugs on a person before finding one that works.

While a complex organ would be the holy grail for most tissue engineers, some like to look even farther ahead, straight into science fiction.

“If one can bioprint functional human organ constructs, then bioprinting a whole human — or whatever will be the name for such a creature — is just a logical extension,” said Vladimir Mironov, a pioneer in the field who is working with computer companies to design better bioprinting software.

Others don’t know why anyone would want to do that.

“It’s a visionary idea,” said Mironov’s colleague Jonathan Butcher of Cornell, whose lab is working on printing heart valves. “But the usual method of human reproduction works pretty well.”