MD+DI Online is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Ahead of Regulatory Approval, iPhone ECG Is Saving Lives—Human and Animal

Ahead of Regulatory Approval, iPhone ECG Is Saving Lives—Human and Animal

The AliveCor iPhone ECG has already been used to diagnose several cardiac conditions and it isn’t even on the market yet—although FDA and CE Mark approvals of the device are pending. A recent study designed to investigate the potential use cases of the technology led to the diagnosis of serious cardiac problems such as silent ischemia, tachycardia, and Wolff-Parkinson-White syndrome in a study involving 54 patients. “None of these people were selected because they were supposed to be patients. We were just looking at the quality of the data,” says David Albert, MD, inventor of the device and chief medical officer of AliveCor.  After the study at the University of Southern California (USC) was completed, 16% of the participants believed they had discovered a health condition that they previously did not know about. After taking part in the study, 24% of the participants contacted their private physicians for a consultation.

In a separate event, Eric Topol, MD, chief academic officer at Scripps Health, used the iPhone ECG on a flight from Dulles to San Diego to diagnose a heart attack, forcing the plane to land so that the patient could be rushed to a hospital. The patient survived the ordeal. 

The aforementioned study at USC was initially organized to learn more about the potential use cases for the iPhone ECG—which are far ranging. The iPhone ECG can be used for everything from consumer use, clinical diagnostics, to veterinary applications. When asked about the latter, Albert says “I can absolutely tell you that our product from the top of the veterinary cardiology, they find it extremely useful on dogs, cats, and even horses. The iPhone ECG is going to be used by veterninarians, by electrophysiologists, cardiologists, internists, family medicine doctors, ER doctors, EMTs, paramaedics, home health nurses, medics, and then by patients themselves,” Albert adds. “Our device is just as appropriate in the hands of an electrophysiologist like Leslie Saxon, MD or cardiologists like Eric Topol, MD as it is in the hands of Brian Buntz—or his dad. And it is just as appropriate in the hands of a veterinarian.” 

David Albert, MD demonstrates the AliveCor Vet ECG on an equine patient at Oklahoma State University.

“It is a device that sort of expands your imagination,” says Leslie Saxon, MD, who designed and oversaw the study. “I never leave home without my iPhone. And as a cardiologist and a heart rhythm doctor, I can obviously use the iPhone ECG on myself, I can use it in the clinic on my patients or in the hospital, and I can even use it at home to get my golden retriever’s ECG.”

Saxon, who is a professor of clinical medicine at the USC Keck School of Medicine, recruited 54 patients from the iPhone-owning demographic in attendance at the annual Body Computing Conference at USC. Participants in the study were not given instructions on how to use the device. People from various background were enrolled: engineers, entertainment, media, bloggers, as well as doctors.

In the study, the participants were provided with a case and an app to use with their iPhone. Without receiving instructions on how to use the product, the participants were told to go and to record their ECG at least once per day.

Over the course of eight weeks, about 1500 ECGs were recorded and transmitted—about 90% of which were clinically useful, Albert says. The participants used the device consistently throughout the duration of the study. Saxon and Albert read the ECGs generated from the study.

Saxon recounts that one of the patients enrolled in the study had received negative cursory screenings for arrhythmia. In the course of the study, however, it became apparent that he had a serious arrhythmia. “It was a very, very good thing that he had [the iPhone ECG] around because he could have been a sudden cardiac death patient.”

I want to reach patients globally, wirelessly all of the time. I want every cardiologist to have that kind of reach.”

In another case, a businessman participating in the study had transmitted an abnormal ECG, which could indicate that the patient’s heart wasn’t getting enough blood. Saxon called the man in the study, who was then in Mumbai on business, and expressed her concern about the ECG reading. The patient informed her that the ECG came from a Nigerian acquaintance he had met at a reception. “And I said, well, go and find him,” Saxon says.

“For me, the gratifying thing was, here I am, I have had 25 years of experience as a heart rhythm doctor, and who can access me? Only patients with an appointment in L.A., right?” In this example, wireless technology enabled her to reach reach a Nigerian, who may have a serious heart condition. “How cool is that? That is really what we talk about in terms of global health and leveraging our experts across the world over mobile. For me that was just a paradigm shift and I thought, gosh, I want to do that for everybody in our division. I want to reach patients globally, wirelessly all of the time. I want every cardiologist to have that kind of reach. And God knows, people need it.”

Brian Buntz is the editor-at-large at UBM Canon's medical group. Follow him on Twitter at @brian_buntz. 

For more on the iPhone ECG, check out the “Ahead of His Time” series of MD+DI articles:

Don't Prejudge Supremes on Obamacare Ruling

For many opponents of Obamacare, it is an article of faith that the Supreme Court will overturn part or all of the Affordable Care Act. They may be in for a rude awakening come June when the Supremes issue their ruling, writes Topher Spiro on theatlantic.com. He blames CNN's Jeffrey Toobin, instant punditry and twitter journalism for the misperception.

"This was a train wreck for the Obama administration," Spiro quotes Toobin as saying. "This law looks like it's going to be struck down." And with that hyperbolic instant reaction, CNN legal analyst Jeffrey Toobin prejudiced media coverage, writes Spiro. A dispassionate reading of the transcript suggests a different outcome, he adds.

While the justices of the Supreme Court probed for a limiting principle and played devil's advocate, as is their wont, Chief Justice Roberts and Justice Kennedy ultimately understood why healthcare is unique and not like, oh, broccoli. Spiro points to several key exchanges that clarified their thinking:

  • Kennedy acknowledged that the uninsured affect costs in a way that doesn't happen in other markets.
  • Kennedy also stipulated that "the young person who is uninsured is uniquely proximately very close to affecting the rates of insurance and the costs of providing medical care in a way that is not true in other industries."
  • Roberts noted that "everybody is in this market, so that makes it very different than the market for cars or the other hypotheticals that you came up with, and all [the government is] regulating is how you pay for it."

There's much more on theatlantic.com, which I encourage you to read. Spiro makes a good case—how compelling it is will depend a great deal on which side of the Obamacare barricades you are on.

Riata Pacing Lead Recall Produces Demands for Increased Postmarket Surveillance

While all major recalls inevitably tend to attract unwanted media attention, patient outrage, and admonishments from the medical community, the recall of the Riata and Riata ST pacing leads has served as a particular lightning rod for criticism of current postmarket surveillance systems. But will the controversy eventually die down or could the Riata recall be the catalyst for significant change?

Recalled by FDA in December, multiple models of the Riata and Riata ST implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) leads were at risk of experiencing externalized conductors. "The silicone insulation covering these defibrillation leads is at risk of premature abrasion. When abrasion occurs, the conductors inside the leads can come out (externalized) of the insulation," according to FDA. "Leads with externalized conductors may develop electrical dysfunction and not work as intended. In the event the device does not work as intended, should a life-threatening heart rhythm occur, pacing or defibrillation therapy may not be delivered as intended. This may result in serious adverse events, including death." News circulated this week that the company's QuickSite and QuickFlex wires were also prone to externalized conductors; St. Jude announced that it would stop selling the two wires.

In the wake of the recall, the Riata leads have been used as one of the go-to examples by critics arguing in favor of increased regulation and postmarket surveillance. Last month, for example, Robert Hauser of the Minneapolis Heart Institute wrote a scathing perspective in The New England Journal of Medicine titled "Here We Go Again--Another Failure of Postmarketing Device Surveillance." Calling out manufacturers and FDA, the piece condemns the lack of scientifically valid information available to physicians to guide them in dealing with the news of the recall. "The problem is that our current passive postmarketing surveillance system fails to detect significant device defects before large patient populations have been exposed. Consequently, we repeatedly find ourselves reacting ineffectively, even dangerously, to big problems with devices by subjecting patients to care strategies that are not supported by solid clinical evidence," Hauser writes.

Despite issuing a letter to physicians one year prior to the recall, neither St. Jude nor FDA launched clinical studies to investigate some of the natural questions that arose from initial reports that something could be awry with the leads, Hauser states. "Should the lead be replaced if the conductors are exposed but electrically intact? Is the ETFE coating on the externalized conductors sufficiently robust to perform reliably--that is, to deliver an effective high-energy shock when needed? Is monitoring with or without routine fluoroscopy a safe alternative to prophylactic replacement? What electrical parameters are important to adhere to?" he asks. "The answers to these questions are needed today, but only now has the manufacturer acknowledged that 'the clinical implications of leads with electrically intact externalized conductors are not fully known at this time. Consequently, more data are required in order to assess if specific patient subgroups with electrically intact externalized conductors are at greater risk or should be managed differently.'" Hauser concludes that St. Jude should launch a postmarket study on the Riata and similar Durata leads, adding that all manufacturers should be responsible for conducting postmarket studies for life-critical Class III medical devices.

While medical device manufacturers will likely disagree with Hauser's assessment, the groundwork for increased postmarket surveillance of Class II and III products has already been laid in such cases as metal-on-metal hip implants and surgical mesh to treat pelvic prolapse. On the heels of seemingly never-ending negative press and a steady stream of new and damning information, FDA issued 145 orders to 21 manufacturers of metal-on-metal hip implants for postmarket surveillance studies last May. Likewise, the agency issued an order in January to 33 manufacturers of surgical mesh, implanted to treat female urinary incontinence, for emergency postmarket studies on the devices that have been deemed by some as 'not worth the risk.'

So, could these events be signaling a trend in increasing postmarket surveillance demands? It's difficult to tell. But between patient safety concerns, the relentless negative press, and prominent criticism of such matters, discontent with current systems is certainly evident and becoming increasingly difficult to ignore. Pacing leads will likely avoid such a fate, but the tide does seem to turning. Do you think mounting criticism and the FDA's recent postmarket surveillance demands indicate impending change for the medical device industry? Or is it just the same-old reaction following a recall? And what do you think the future holds for pacing leads, and St. Jude's models in particular? Let us know in the comments section below and weigh in on our poll below. --Shana Leonard

Porous Metal Films With Record-Setting Conductivity Offer Potential Biomed Applications

Porous metal films with high conductivity at Cornell University
Samples of self-assembled metal-containing films made by the new sol-gel process. The films are essentially glass in which metal atoms are suspended, which imparts the color. Grid lines are 5 mm apart. Image: Wiesner Lab/Cornell University

Chemists at Cornell University have developed a way to make porous metal films with up to 1,000 times the electrical conductivity provided by previous methods. Their technique offers potential for creating a variety of metal nanostructures for engineering and biomedical applications, the researchers said. It builds on the sol-gel process already familiar to chemists: Certain compounds of silicon mixed with solvents will self-assemble into a structure of silicon dioxide (i.e., glass) honeycombed with nanometer-scaled pores. The challenge facing the researchers was to add metal to create a porous structure that conducts electricity.

About 10 years ago, the research group led by senior author Ulrich Wiesner (Spencer T. Olin Professor of Engineering), collaborating with the Cornell Fuel Cell Institute tried using the sol-gel process with the catalysts that pull protons off of fuel molecules to generate electricity. They needed materials that would pass high current, but adding more than a small amount of metal disrupted the sol-gel process, explained Scott Warren, first author of the Nature Materials paper. Warren, who was then a PhD student in Wiesner's group and is now a researcher at Northwestern University, hit on the idea of using an amino acid to link metal atoms to silica molecules because he had realized that one end of the amino acid molecule has an affinity for silica and the other end for metals. "If there was a way to directly attach the metal to the silica sol-gel precursor, then we would prevent this phase separation that was disrupting the self-assembly process," he explained.

The immediate result is a nanostructure of metal, silica, and carbon, with much more metal than had been possible before, thereby greatly increasing conductivity. The silica and carbon can be removed, leaving porous metal. But a silica-metal structure would hold its shape at the high temperatures found in some fuel cells, Warren noted, and removing just the silica to leave a carbon-metal complex offers other possibilities, including larger pores. The researchers report a wide range of experiments showing that their process can be used to make "a library of materials with a high degree of control over composition and structure." They have built structures of almost every metal in the periodic table, and with additional chemistry can tweak the dimensions of the pores in a range from 10 to 500 nanometers. They have also made metal-filled silica nanoparticles small enough to be ingested and secreted by humans, with possible biomedical applications.

Michael Graetzel of the École Polytechnique Fédérale de Lausanne and innovator of the Graetzel cell is a co-author of the new paper. The measurement of the record-setting electrical conductivity was performed in his laboratory.

The research has been supported by the Department of Energy and the National Science Foundation.

Are You a Top Contract Manufacturer?

Medtech 40 Under 40 Nominations

Panasonic Forms North American Healthcare Subsidiary

Called Panasonic Healthcare Co. of North America, the new entity will be based in Secaucus, NJ, with additional operations in Wood Dale, IL, and Houston. Yoshi Yuasa, who previously served as head of Panasonic Healthcare Group, will serve as president, according to a press release.

The company will focus on digital hearing instruments, the CardioHealth Station, pharmacy automation technology, and other biomedical and life science support products. It will also concentrate on energy savings and improving the efficiency of healthcare operations, in line with parent company Panasonic Corp.’s goal of becoming the leader in green innovation in the electronics industry by 2018, according to the release.

“We have formed Panasonic Healthcare Co. of North America with the aim of anticipating society’s changing demands in the healthcare market,” Joe Taylor, chairman and CEO of Panasonic Corp. of North America said in a statement. “Panasonic will continue to service the needs of life science customers with innovative products and solutions. As a leader in the technology field, Panasonic has much to offer both the medical devices and life sciences research communities and we believe that we can make a significant contribution in helping to meet their evolving needs.”

Jamie Hartford is associate editor of MED and MD+DI. Follow her on Twitter at @readMED.

FDA Has a Bone to Pick with Small Medical Device Companies

What is it about CDRH that — notwithstanding Congressional orders to pursue “least burdensome” approaches — so often causes it to bend or break its own rules? The agency often deals roughly with small companies that have unusual products that don’t easily fit cookie-cutter regulatory approaches.

In the lengthening stream of earlier examples (think neuromuscular dental device maker Myo-Tronics (Kent, WA), external automatic defibrillator maker Laerdal (Wappingers Falls, NY), and neonatal and gynecological monitoring devices maker Utah Medical Products (Midvale, UT), and Bio-Clinical Systems (Anyang City, Korea), all of whom defeated the Center at huge legal cost) now add cranial electrotherapy stimulator maker Electromedical Products International (Mineral Wells, TX), which is still fighting.

There are many others that did not win (think TMJ Implants, driven into bankruptcy over CDRH’s refusal/inability to explain the scientific basis of its decision that its jaw implants caused injuries that must be reported under MDR regulations — or think device gas sterilizer maker Andersen Products (Haw River, NC) driven almost to bankruptcy — or others that gave up just to protect their reputations).

All had one thing in common: they were small (less than 50 employees) and consequently had too much at stake to give in without a fight.

In Electromedical Products International’s (EPI) case, the fight is about whether its only product line, Alpha-Stim, a noninvasive, non-life supporting medical device that’s been on the market for more than 30 years without any serious complaints and is sold over-the-counter everywhere else in the world, should be a Class III device.

CDRH has been bumbling around on this question since 1978, but now shows signs of getting serious. Confronting EPI with the prospect of having to conduct rigorous, well-designed, double-blind clinical studies in more than 50 patients or leave the market, CDRH convened a 14-member meeting of its Neurological Devices Panel in February to consider whether CES devices like Alpha-Stim should stay in Class III or go into Class II as this and other companies have petitioned for.

The devices’ Class III status has been in contention since 1978, CDRH always backing off in a funk, sometimes for a decade or more, when challenged.

Little wonder. Consider the usual and customary characteristics of a Class III device: supports or sustains human life, or is of substantial importance in preventing impairment of human health, or presents a potential, unreasonable risk of illness or injury. CES devices don’t conform to either criterion.

But the 1976 Medical Device Amendments apparently foresaw such situations because they gave the Secretary the non-mandatory option (delegated down in this case to CDRH) to “conduct such activities as may be necessary to develop or obtain” sufficient information to establish a device’s safety and effectiveness.

EPI says CDRH has selectively rejected nearly all of its safety and effectiveness information on Alpha-Stim because the data involved studies in fewer than 50 patients, were not presented in English, were unpublished, or conducted in animals — leaving it reliant on “questionable” 1970s data to which CDRH has applied 2012 review standards.
But the Food, Drug & Cosmetic Act contains an alternative standard for Class III device evaluation: “valid scientific evidence” which the act says “the Secretary may” elect to consider: human experience with a marketed device (more about this in a moment).

A pressingly obvious question at this point is why expend taxpayer resources on demanding Class III for these devices in the first place, given their lack of medical controversy?

CES Devices and Device Classification

A classification panel in 1978 had given as a reason for putting CES devices in Class III its belief that “it is not possible to establish an adequate performance standard for this device because the characteristics of the electrical current necessary for effectiveness are not known. The panel believes that general controls will not provide sufficient control over these characteristics.” It further went on to opine the devices present “a potential unreasonable risk of illness or injury to the patient if the practitioner relies on the device, and it is ineffective in treating the patient's illness.”

CDRH promptly went to sleep on the matter for 15 years. In 1993, it proposed a rule requiring a PMA for the devices, reiterating the classification panel members’ views and presenting no new data about harmful effects or safety. Simultaneously, CDRH rejected imperfect studies presented by sponsors.

The rule was finalized in 1995, but revoked two years later after EPI sued the agency, causing it to briefly convert to full flexibility and admit in the Federal Register that it had “become aware of additional information relevant to the possible reclassification of the CES device from Class III to Class II or Class I.” It then announced that it believed it was “more appropriate” to invoke the procedures under section 515(i) of the Food Drug & Cosmetic Act and issue an order requiring manufacturers of CES devices to submit information on their devices’ safety and effectiveness.

It took CDRH another 14 years to get serious about that. In April, 2009 it published a 515(i) notice that applied to all of the 25 remaining devices, including EPI’s Alpha-Stim, that still held Class III preamendments status “as the first step in the process of final rule-making.” Letters went out giving their makers four months to respond. The Center then slumbered on the issue for another four years until last August, when it snapped back to its original 1978 position, proposing to require PMAs for the CES devices. That’s when EPI and two other CES makers petitioned CDRH for Class II status.

In addition to those petitions, CDRH received over 200 comments, most of which the agency implied were in favor of Class II (FDA as a matter of policy does not discuss comments to its dockets in a vote-counting or popularity contest kind of way, thereby preserving its flexibility to decide against the majority if it should elect to do so).

Lacking its own expertise to evaluate the sponsor petitions, CDRH convened the Neurological Devices Panel (NDP) to consider them. None of the members disclosed “qualified expert status” in CES devices, but they were provided with what EPI calls a biased 83-page CDRH executive summary that argued for Class III status on the same vague grounds the Center had used in 1993.

In an apparent effort to ensure the panel’s acquiescence, CDRH failed to instruct it on the regulatory standard of “valid scientific evidence” they were to apply to the information being considered. At 21 CFR 860.7(c)(2), this is described as “evidence from well-controlled investigation, partially controlled studies and objective trials without match controls, well-documented case histories conducted by qualified experts, and reports of significant human experience with a marketed device, from which it can fairly and responsibly be concluded by qualified experts that there is reasonable assurance of the safety and effectiveness of a device under its conditions of use.” (Emphasis added.) This omission by CDRH was deliberate, EPI counsel Larry R. Pilot says, and it misled panel members into thinking that valid scientific evidence did not include marketing experience. This degraded the quality of EPI’s evidence, with one panel member even disparaging it as “testimonials.”

Asked by CDRH whether, based on the available scientific evidence, the probable benefits to health from use of CES for these indications (treatment of insomnia, depression and anxiety) and conditions of use, outweighed the probable risks, most panel members said they did not — although chairman Robert W. Hurst (Hospital of the University of Pennsylvania) qualified that in his summary by observing that several members expressed “reservations due primarily to what appears to be complete lack of safety concerns. Don’t see any safety problems.”

Despite this, the panel voted to keep CES in Class III because there was no showing of effectiveness. EPI vice president Scott Elder attributes that to CDRH’s prejudicial rejection of most of the company’s studies.

As for CDRH’s compilation of CES risks as suggested by unverifiable MAUDE database reports — Worsening of the condition being treated as a result of ineffective treatment, potential adverse effects from electrical stimulation of the brain, potential risk of seizure, skin irritation, headaches, blurred vision — the panel unanimously rejected it as inaccurate and incomplete, agreeing only with skin irritation and headaches and in two cases wanting to add dizziness. CDRH introduced “potential risk of seizure” (a consequence that can be fatal) from MAUDE while admitting that the only reports there involved seizures that occurred before CES was used.

“Roughly eight and one quarter million CES treatment were administered in the past five year by Alpha-Stim alone,” Elder says, “and no one during its 31 years of experience ever reported a seizure.” Of course, that doesn’t mean no one ever will, and CDRH accordingly remains open to that hypothetical possibility.

As in too many other episodes targeting small companies with unusual devices in this most dysfunctional of FDA Centers over the years, here appears another instance of CDRH serial malfeasance. This non-life-sustaining product clearly does not conform to the usual Class III criteria, so the Center seems to have distorted those criteria again and again since 1978 to contrive a fit, and in the process to have broken its own rules for fair conduct in advisory panel consultation.

CDRH does have one friend in its treatment of CES devices. Public Citizen Health Research Group director Sidney Wolfe, who can usually be relied upon to oppose any corporate position, has strongly urged Center director Jeffrey Shuren after the NDP meeting to hold fast to the Center’s Class III decision. When attorney Pilot pointed out the flaws and legal failings in that decision, Wolfe declined to alter HRG’s position, saying it was based on “publicly available material.”

So like so many small companies before it when confronted with CDRH wrong-headedness, EPI faces significant and unnecessary hardship on the road ahead — in its case, the expense of conducting — as Wolfe expressed it — “rigorous, well-designed, controlled, double-blind” clinical trials if it wants to keep Alpha-Stim on the U.S. market.
Whatever became of the 12-year-old statutory requirement for CDRH to pursue the “least burdensome” approach mandated by Congress to regulating device companies?

In the aftermath of last year’s uproar over the dysfunctional 510(k) program at CDRH, to say nothing of its incapacity to curb marketing abuses by the out-of-control LASIK eye surgery industry or to protect consumers from mercury exposure in dental amalgams, it’s past time for a top-to-bottom rebuild there, with a top priority on its internal culture.
 

Nanoparticle Carrier Could Enable Clinicians to Use Nitric Oxide to Treat Wounds

Based on a nanoparticle platform composed of silane-based sol-gel and sugar-derived glasses, researchers at Albert Einstein College of Medicine (Bronx, NY) are developing a carrier for nitric oxide (NO), a compound that plays an important role in the wound-healing process because of its antimicrobial and other properties. The nanoparticle carrier can generate, store, and deliver NO in a controlled and sustained manner.

"Mechanistically, we found that NO-np treatment accelerates wound healing as a result of increasing tissue concentrations of TGF-b, a potent cytokine with broad and extensive effects on wound healing ranging from macrophage and fibroblast recruitment to collagen deposition to neoangiogenesis," explains Adam Friedman Nanowerk. "Based on these findings, we hypothesized that the NO-np can accelerate healing in a murine model of impaired wound healing in the setting of immunodeficiency."

Similar to previous results with the NO-np, it was found that treatment with NO-np significantly increased wound closure clinically, correlating to the increased and well-organized collagen deposition and new vessel formation seen histologically, explains Friedman, director of dermatologic research and associate residency program director at the Unified Division of Dermatology of Montefiore Medical Center--Albert Einstein College of Medicine.

Wound treatment in patients with either inherent or iatrogenic immunosuppression is challenging. Because NO boasts numerous biological properties, its use may enable physicians to address and ameliorate microbial colonization and infection or poor perfusion to retarded migration of epithelial cells.

Developing Graphene Coatings, One Carbon Atom at a Time

Because they are exposed to a fluidic environment, metal-based medical device implants are susceptible to corrosion. In the case of intravascular stents, for example, FDA warns that corrosion can cause or contribute to premature stent failure, generate toxic by-products, or result in adverse biological and tissue responses. Seeking to develop a new generation of coatings that could eventually be used to prevent such issues, researchers at Vanderbilt University (Nashville) are exploring the use of graphene, a corrosion-resistant material with a variety of properties that could render it suitable for implantable medical devices.

Vanderbilt graphene coating
A piece of copper foil with a graphene coating has not oxidized, while a piece of foil without the coating (right), shows the effects of oxidation.

Consisting of carbon atoms that form a single monolayer of graphite, graphene is impervious to corrosion, comments Kirill Bolotin, an assistant professor of physics at Vanderbilt. "For example, cyclic voltammetry measurements that we have performed show that it effectively suppresses metal oxidation and oxygen reduction. And electrochemical impedance spectroscopy measurements suggest that a graphene coating on top of a metal substrate remains undamaged, while the metal itself corrodes where cracks in the graphene film form." These findings confirm earlier study results from Rodney Ruoff at the University of Texas at Austin and Jiwoong Park at Cornell University.

Tafel analyses, also performed by Bolotin and his team, highlight graphene's superiority over an assortment of bare metals. Thus, while copper films coated with the material corrode seven times slower in an aerated Na2SO4 solution than bare copper, nickel coated with a multilayer of graphene film corrodes 20 times slower than bare nickel. Furthermore, nickel surfaces coated with four layers of mechanically transferred graphene corrode four times slower than the bare metal, according to the group's studies.

In addition to exhibiting corrosion-resistance, graphene is the world's thinnest material. Indeed, it is so thin that a single layer is transparent, and it is so light that an ounce of it would cover 28 football fields. But despite its thinness, graphene is completely impermeable to even the smallest molecules, such as helium. "These properties make it uniquely suitable for applications such as a coatings," Bolotin remarks.

Graphene, according to Bolotin, also features others properties that make it potentially suitable for use in corrosion-resistant coating applications. For example, it can be grown on many different types of metals, including copper, nickel, and ruthenium, and it can also be mechanically transferred onto other types of metals. In addition, because graphene is chemically inert, it is biocompatible, making it suitable for use in medical device applications.

"However, one problem that is likely to be encountered is mechanical abrasion," Bolotin cautions. "It's not clear to what extent a monolayer of graphene can withstand mechanical friction. Thus, a graphene coating would most likely be suitable for implant applications that do not involve high levels of friction."