Category Archives: MEMS

AIXTRON SE today announced that it is participating as a key partner in the recently announced European Union (EU) Future Emerging Technology (FET) flagship project “Graphene.” As part of the consortium, AIXTRON will bring its expertise in deposition processes for graphene and as such shall lead the production work package of the flagship.

“Congratulations to the leadership and partners of the Graphene Flagship,” Dr. Bernd Schulte, Chief Operating Officer at AIXTRON, said. “AIXTRON is proud to be a part of this future-oriented research initiative, which will have considerable impact on the European economy.”

Dr. Ken Teo, director of Nanoinstruments at AIXTRON, said AIXTRON’s key contribution will be to enable high-quality large-scale graphene growth through the development of next generation deposition equipment.

“Working with graphene thin-film producers, bulk graphene manufacturers and associated partners, graphene will be produced for a variety of applications ranging from wireless communications to display, sensing and energy storage,” said Teo. “This is a unique opportunity for us to interact with and understand the requirements of R&D and industrial end-users.”

“For a disruptive new material such as graphene, long-term investment is required to create the entire value chain and end market applications,” Dr. Schulte added. “Support for the Graphene Flagship over the next decade by the EU is indeed a significant commitment that makes this possible. The development furthermore confirms AIXTRON’s long-term strategy in enabling the deposition of new electronic materials such as graphene.”

Chalmers University of Technology in Sweden, with Prof. Jari Kinaret as the flagship director, will coordinate 126 academic and industrial research groups in 17 European countries. The EU funding for the academic-industrial consortium starts with an initial 30-month-EU budget of 54 million euro which will be extended up to 10 years with 1 billion Euro total project cost, with further contributions coming from the Horizon 2020 program and local programs from various EU countries.

Graphene Flagship project
A 300 mm wafer of graphene produced on an AIXTRON system, presented by Prof. Jari Kinaret, Director of the Graphene Flagship, and Neelie Kroes, EU Digital Agenda Commissioner.

University of Manchester graphene researchers have been awarded a £3.5 million (or approximately US$5 million) funding boost that could bring desalination plants, safer food packaging and enhanced disease detection closer to reality.

Funded by the Engineering and Physical Sciences Research Council (EPSRC), the research focuses on membranes that could provide solutions to worldwide problems: from stopping power stations releasing carbon dioxide into the atmosphere, to detecting the chemical signals produced by agricultural pests.

The latest research grant comes just months after The University of Manchester was awarded £2.2 million (or approximately US$3 million) to lead research into graphene batteries and supercapacitors for energy storage.

No molecules can get through a perfect sheet of graphene and when platelets of graphene are built into more complex structures, highly selective membranes can be generated.  The aim is, together with industrial partners, to produce working membranes for applications related to sustainability, energy, health, defense and food security.

Wonder material graphene was first isolated in 2004 at The University of Manchester by Professor Andre Geim and Professor Kostya Novoselov. Their work earned them the 2010 Nobel prize for Physics.

Graphene is the world’s thinnest, strongest and most conductive material, and has the potential to revolutionize a huge number of diverse applications; from smartphones and ultrafast broadband to drug delivery and computer chips.

The membrane program builds on ground-breaking research at the University. Previous research showed that graphene oxide membranes are highly permeable to water, while being completely impermeable to gases and organic liquids when dry.

These membranes will be developed for a variety of applications, such as the removal of water when making biofuels by fermentation, and as components of fuel cells.

The research is led by Professor Peter Budd, of the School of Chemistry. He said: “We have also invented a range of polymers – called Polymers of Intrinsic Microporosity (PIMs) – which form membranes that are very good for separating gases and organic liquids.

“These are of interest, for example, for removing carbon dioxide from power station flue gases, or for removing organic compounds from water.  By combining PIMs with graphene, we expect to produce membranes with even better performance under long-term conditions of use.

“We will also be looking at practical ways of using the ability of graphene to act as a perfect barrier in, for example, food packaging, and we will be building graphene into sensors for detecting human diseases and agricultural pests.”

It’s no secret that Samsung is up against Apple in many ways, in products, sales and innovation. However, even in the face of Apple’s patent infringement lawsuits, Samsung is still climbing the charts. The electronics giant sold approximately $53 billion in revenue in the last quarter of 2012, in comparison to Apple’s $36 billion in revenue, though the profit margins both companies are seeing were relatively similar. And while Bloomberg is predicting Apple will post its lowest sales increase since 2009, Samsung is reportedly poised for big growth in a number of sectors.  

Samsung grabs No. 3 foundry spot

Samsung jumped into the foundry scene in mid-2010, and quickly became one of the anticipated long-term leaders in the sector. It’s now easily the biggest IDM foundry operation, with sales nearly 10 times that of IBM, IC Insights noted in January. IC Insights’ August update projected Samsung finishing in fourth place just behind UMC, separated by about $400 million, but anticipated Samsung surpassing the Taiwan rival in 2013.

Samsung followed a sparkling 82 percent growth in 2011 by nearly doubling sales again to $4.33 billion, putting it just shy of GLOBALFOUNDRIES which grew sales a solid 31 percent last year to $4.56B. In fact IC Insights believes Samsung will challenge GLOBALFOUNDRIES for the No.2 spot before 2013 is done, leveraging its leading-edge capacity and huge capital spending budget. With dedicated IC foundry capacity reaching 150,000 300mm wafers/month by 4Q12, and an average revenue/wafer of $3000, Samsung’s IC foundry capacity could pull down $5.4B in annual sales, the analyst firm calculates.

How did Samsung get so big so fast in the foundry business? It supplied chips to nearly half of the industry’s 750 million smartphones shipped in 2012 — application processors for the 220 million of its own handsets in 2012, plus the 133 million iPhones Apple shipped.

Thanks to the Galaxy S4, Samsung has 99% of the AMOLED market

Samsung has invested a considerable amount into the AMOLED market, which is now poised for steady growth, thanks to a growing demand for high-end smartphones and tablets. According to Forbes contributor Haydn Shaughnessy, Samsung now holds 99% of the AMOLED market.

AMOLED display shipments for mobile handset applications are expected to grow to 447.7 million units in 2017, up from 195.1 million units in 2013, according to insights from the IHS iSuppli Emerging Displays Service at information and analytics provider IHS. Within the mobile handset display market, the market share for AMOLED displays is forecast to grow from 7.9% in 2013 to 15.2 percent in 2017, as presented in the figure below. AMOLED’s market share for 4-inch or larger handset displays employed in smartphones is set to increase to 24.4% in 2017, up from 23.0% in 2013.

“Because of their use in marquee products like the Galaxy S4, high-quality AMOLEDs are growing in popularity and gaining share at the expense of liquid crystal display (LCD) screens,” said Vinita Jakhanwal, director for mobile & emerging displays and technology at IHS. “These attractive AMOLEDs are part of a growing trend of large-sized, high-resolution displays used in mobile devices. With the S4 representing the first time that a full high-definition (HD) AMOLED has been used in mobile handsets, Samsung continues to raise the profile of this display technology.”

Samsung anticipates MEMS pressure sensor market boom

Samsung has been ahead of its time in its adoption of MEMS pressure sensors, anticipating the state of the market and getting a jump on the competition.

Global shipments of MEMS pressure sensors in cellphones are set to rise to 681 million units in 2016, up more than eightfold from 82 million in 2012, according to the IHS iSuppli MEMS & Sensors Service at information and analytics provider IHS. Shipments this year are expected to double to 162 million units, as presented in the attached figure, primarily due to Samsung’s usage of pressure sensors in the Galaxy S4 and other smartphone models.

“Samsung is the only major original equipment manufacturer (OEM) now using pressure sensors in all its flagship smartphone models,” said Jérémie Bouchaud, director and senior principal analyst for MEMS and sensors at IHS. “The pressure device represents just one component among a wealth of different sensors used in the S4.”

Besides Samsung, few other OEMs have been using pressure sensors in smartphones. The only other smartphone OEMs to use pressure sensors in their products are Sony Mobile in a couple of models in 2012, and a few Chinese vendors, like Xiaomi.

Apple, which pioneered the use of MEMS sensors in smartphones, does not employ pressure sensors at the moment in the iPhone. However, IHS expects Apple will start them in 2014, which will contribute to another doubling of the market in 2014 to 325 million units.

But what about the patent infringement suit?

Six months after Samsung was ordered to pay an unprecedented $1.05 billion to Apple in the notorious patent infringement suit, Judge Lucy Koh, the federal judge presiding over two Apple v. Samsung cases in California, entered an order striking $450 million from the damages award determined by a jury in August 2012. This corresponds to 14 of the 28 Samsung products in question in the initial lawsuit. Koh disagreed with the notice date provided by Apple concerning its patents-in-suit, and, as a result, a new damages trial must be held, most likely after the appellate proceedings, which were sought by both parties.

The new trial could mean good news or bad news for Samsung. There is the possibility that the court could rule in favor of a reduction of damages to be paid. However, it is also just as likely that the court could rule Samsung owe Apple even more than the original $1.05 billion ordered in August.

Some analysts have speculated that, if the suit holds, consumers could see a jump in prices of Samsung, Google and Android devices. Only time will tell if will a price that the masses will be willing to pay. If it is, don’t expect to see Samsung slowing down any time soon.

STMicroelectronics has begun working with research partners to develop a pilot line for next-generation MEMS devices augmented with advanced technologies such as piezoelectric or magnetic materials and 3D packaging. The project was launched by the European Nanoelectronics Initiative Advisory Council (ENIAC) Joint Undertaking (JU), a public-private partnership in nanoelectronics. 

In coordinating the €28m, 30-month Lab4MEMS project, ST is working with universities, research institutions and technology businesses across nine European countries. The project benefits from ST’s MEMS facilities in France, Italy and Malta to establish a complete set of manufacturing competencies for next-generation devices, spanning design and fabrication to test and packaging.

With over 800 MEMS-related patents, more than three billion devices shipped and extensive in-house production capabilities currently producing more than 4 million MEMS devices per day, ST is ideally placed to lead the Lab4MEMS research into next-generation devices. The project will develop technologies such as Piezoelectric (PZT) thin films to enhance current pure-silicon MEMS, enabling improvements such as larger displacement, higher sensing functionality and greater energy density. These are needed to build smart sensors, actuators, micro pumps and energy harvesters meeting the demands of future data-storage, ink-jet, healthcare, automotive, industrial-control and smart-building applications, as well as consumer applications such as smartphones and navigation devices.

The project will also develop advanced packaging technologies and vertical interconnections using flip-chip, through-silicon vias and through-mold vias, enabling 3D-integrated devices for applications such as body area sensors and remote monitoring. A key target is to perfect a PZT deposition process compatible with mass production, and integrate it into complex MEMS processes to enable innovative actuators and sensors on System-On-Chip industrial products.

Lab4MEMS is one of the Key Enabling Technologies (KET) Pilot-Line projects contracted by the ENIAC JU to develop technologies and application areas with substantial societal impact.

“The ENIAC JU research agenda has synergies with ST’s commitment to improving quality of life through technology,” said Roberto Zafalon, European Programs Manager, R&D and Public Affairs, STMicroelectronics. “Lab4MEMS is an important project that will benefit consortium members and stakeholders, including ENIAC member states. Ultimately, we expect the results to translate into long-term prosperity and valuable knowledge-based employment opportunities.”

The ENIAC JU is a public-private partnership involving ENIAC member states, the European Union, and the Association for European Nanoelectronics Activities (AENEAS). It is currently contributing some €1.8bn towards the costs of R&D projects, which it selects through a competitive process assessing responses to its Calls for Proposals. The Lab4MEMS project, coordinated by ST, was selected in 2012 and work began in January 2013.

India registered 221.6 million mobile handset shipments during 2012, according to CMR’s India Mobile Handsets Market Review, CY 2012, March 2013 release. During the same period, 15.2 million smartphones were shipped in the country.

A comparison of overall mobile handset shipments and featurephone shipments shows a direct correlation for the India mobile handsets market rankings. Market shares are somewhat similar for the top three players across the overall market and the featurephones segment, as shown in Table 2.

Commenting on the results, Faisal Kawoosa, lead analyst, CMR Telecoms Practice said, “Although we see a huge market ‘hype’ around smartphones, the fact remains that the India Mobile Handsets market is still dominated by shipments of featurephones. On the other hand smartphone shipments are growing fast. This indicates India is still a ‘new phone’ market, where featurephones contribute to the bulk of shipments compared to replacements or upgrades.

“This propensity on the part of Indian subscribers of mobile telephony services to purchase large numbers of featurephones has paved the way for the establishment of Indian brands, which are largely focused on this segment.”

India Smartphones Market

The India smartphones market during 2H 2012 saw a rise in shipments by 75.2 percent over and above the 1H 2012 number, taking the overall contribution of smartphones to 6.8% for the full year. In fact, during 2H 2012, smartphone shipments stood at 8.1 percent of the country’s total mobile handset shipments. While BlackBerry was at third spot during 1H 2012, Sony Mobiles displaced the former if we examine numbers for the full CY 2012.

Commenting on these results, Tarun Pathak, analyst, CMR Telecoms Practice said, “The India smartphones segment has very distinct characteristics vis-à-vis the overall market. We believe the struggle for leadership in the India smartphones market is going to intensify through 2013 as vendors bring new form factors to market.

“Players such as Samsung, HTC and Sony Mobiles will increasingly try to establish leadership through differentiated offerings and by promising a ‘seamless’ experience across the four consumer screens – smartphone, tablet, PC and TV. At the same time, home grown vendors such as Micromax, Karbonn and Lava will try to make a mark against their global competitors, by bringing to market powerful, yet attractively priced smartphones in an attempt to widen their appeal and grow the overall smartphone user base,” Tarun added.

As testament to Governor Andrew Cuomo’s educational blueprint, Zachary Olmsted, a junior Nanoscale Engineering major at SUNY’s College of Nanoscale Science and Engineering (CNSE), has been chosen to receive the prestigious Barry M. Goldwater Scholarship, the second consecutive year that a CNSE student has been honored with the nation’s premier undergraduate award designed to foster and encourage outstanding students to pursue careers in the fields of mathematics, the natural sciences, and engineering.

“I am delighted to congratulate Zachary Olmsted from our world-class College of Nanoscale Science and Engineering, whose notable recognition as a recipient of the Barry M. Goldwater Scholarship identifies him as one of the nation’s top undergraduate scientific scholars,” said SUNY Chancellor Nancy L. Zimpher. “I also commend Dr. Alain Kaloyeros and CNSE for their critical role in supporting the SUNY system’s ability to develop a new generation of high-tech talent that will be an invaluable asset for New York’s future.“

 “I am thrilled for Zach and proud of his many achievements, and want to congratulate him on this well-deserved recognition as a Goldwater Scholar,” said CNSE Associate Professor of Nanobioscience Dr. Janet Paluh, who is Olmsted’s academic advisor. “This award is a reflection of his demonstrated excellence in both the classroom and the laboratory, and a tribute to his passion for, and commitment to, next-generation scientific discovery and exploration at the interface of biology with man-made materials.”

A native of Oneida, New York, Olmsted is one of only 271 students to be recognized nationwide. He was selected on the basis of academic merit from a field of 1,107 mathematics, science, and engineering students who were nominated by the faculties of colleges and universities across the country. As part of the award, Olmsted will receive $15,000 in funding for his undergraduate studies over the next two years.

In his research, Olmsted is using the fundamental principles of materials science, biology, and device engineering to develop novel biomedical applications, with a focus of integrating biologic components with devices. Working at both the protein-level, using the model yeast system, and at the cell/organ-level, using pluripotent stem cells, these biosynthetic interfaces show promise to develop new cancer therapeutics and drug testing platforms that will alleviate sole reliance on animal studies. Olmsted, who received an honorable mention in last year’s competition, plans to pursue an M.D./Ph.D. in Nanomedicine, a joint program of CNSE and SUNY Downstate Medical Center.

“The selection of a CNSE student for the prestigious Goldwater Scholarship for the second year in a row underscores the growing recognition of CNSE’s undergraduate program as a hallmark for academic and research excellence,” said Dr. Daniel White, CNSE Associate Vice President for Student Affairs and Professional and Corporate Recruitment and Outreach. “We are pleased to see Zachary receive this honor, which reflects positively on CNSE’s innovative educational paradigm and further defines our student body as among the best in the nation.”

In 2012, Sheila Smith, a Pittstown, New York native who is currently a junior at CNSE majoring in Nanoscale Engineering, was honored with the Goldwater Scholarship.

Student receives nation's most prestigious award for science and engineering

Zachary Olmsted and Dr. Janet Paluh using a

Zeis fluorescence microscope to study a skin cell

In addition, Chase Brisbois, a junior majoring in Nanoscale Science at CNSE, received an honorable mention. Advised by Professor of Nanoscience Dr. Robert Brainard, his research targets the development of photo-imageable hydrogels that self-assemble into 3D scaffolds, which are designed to enable new capabilities and scientific advances in the field of tissue engineering. Brisbois is a native of South Lyon, Michigan.

Designed to alleviate a critical current and future shortage of highly qualified scientists, mathematicians, and engineers in the United States, the Barry M. Goldwater Scholarship provides a continuing source of highly qualified individuals to those fields of academic study and research.

Goldwater Scholars have very impressive academic qualifications that have garnered the attention of prestigious post-graduate fellowship programs. Recent Goldwater Scholars have been awarded 80 Rhodes Scholarships, 118 Marshall Awards, 110 Churchill Scholarships and numerous other distinguished fellowships. Since its first award in 1989, the Foundation has bestowed over 6,550 scholarships worth approximately $40 million.

The high-value microelectromechanical system (MEMS) market experienced soft growth last year, mainly due to weakness in the mainstay medical electronics and industrial sectors, according to an IHS iSuppli MEMS High-Value MEMS Market Tracker Report from information and analytics provider IHS.

Revenue in 2012 for high-value MEMS, a market characterized by the lofty average selling prices compared to other MEMS devices, amounted to $1.63 billion, equivalent to growth of 6.5 percent from $1.53 billion in 2011. While revenue was up, growth was noticeably down from the 12.5 percent expansion of 2011.

This year will see a slightly improved 7.4 percent increase to $1.8 billion as the industry starts to recover during the second half. Growth then picks up by 2014 and rises to 10.3 percent, with 2015 and 2016 also forecast to experience solid upturns north of 9.0 percent, as shown in the figure below.

MEMS revenue slows

“The high-value MEMS market last year suffered a deceleration in growth because of continuing slow sales in medical electronics as well as a broad-based downturn in the industrial segment,” said Richard Dixon, Ph.D., principal analyst for MEMS & Sensors at IHS. “In medical electronics, the market performance has been sluggish for the last 18 months, echoing global economic uncertainties. The same macroeconomic headwinds also curtailed end-user demand in industrial electronics semiconductors, inflicting further pain. The high-value MEMS market was aided slightly by strong performance in the telecom, aerospace, and oil and gas sectors, which served to ameliorate the negative effects of the slow-moving sectors.”

Higher growth expected for high-value MEMS

Despite the diminished growth of 2012, the high-value MEMS market remains the second-fastest-expanding area in the broader MEMS space, coming in after the mobile and consumer market but leading the data processing and automotive segments. High-value MEMS accounted for 19 percent of the total MEMS industry last year, despite extreme fragmentation of the space with well over 100 suppliers. The average selling prices of sensors used in high-value MEMS are also much higher than the prices of sensors used in other MEMS segments, which gives the high-value MEMS industry its strength and importance.

Results sluggish in most high-value MEMS segments

Six sectors make up approximately 95 percent of the high-value MEMS market. The largest is medical electronics, accounting for more than 80 percent of total high-value MEMS shipments last year.

The majority of medical electronics sensors are used for diagnostics, patient monitoring and therapy.

For instance, tens of millions of pressure sensors are used and thrown away annually, with the sensors deployed to monitor the blood pressure of patients during and after major operations. Pressure and flow sensors are also used in devices like ventilators and respirators; implantable devices such as cardiac monitors; thermometers; and infusion pumps for introducing fluids, medication or nutrients into a patient’s circulatory system.

The depressed performance in medical electronics was also present in other high-value MEMS segments.

The test and measurement space, especially in semiconductor testing and wafer processing, was flat to down last year. Likewise, the industrial segment governing power tools and transportation exhibited anemic results.

Weak growth expected

Two high-value MEMS segments registered growth but were weak at best: building and home control on the one hand, with smart meters declining last year; and manufacturing and process automation on the other, because of low growth in areas like industrial motors.

In the energy generation and distribution segment, results were mixed. Spending on utilities was down and wind turbine deployments were slowing, but oil and gas showed strong demand in the third quarter based on shale discoveries.

The one segment of the high-value MEMS industry that was up strongly last year was military and civil aerospace. Despite a decelerating missiles and munitions market, the segment more than made up with the extremely robust commercial aircraft sales of the Airbus from Pan-European maker EADS, as well as of the Dreamliner planes made by U.S maker Boeing.

Six devices made up 83 percent of the high-value MEMS market last year. The biggest was microbolometers—tiny arrays of heat-detecting sensors sensitive to infrared radiation—used in firefighting, law enforcement and surveillance systems.

Other prominent high-value MEMS devices include pressure sensors, optical MEMS in telecommunications, wafer probes for semiconductor testing, inkjet printer heads, and accelerometers for gadgets like pacemakers.

Nanosys, enabling a new generation of high color fidelity, energy-efficient displays with its quantum-dot technology, today announced that it has expanded into a new, high-capacity production facility in Milpitas, California.

Nanosys’ new 60,000 square foot facility will produce over 1,000 kilograms of quantum dots per year- enough material to build more than five million 55" quantum dot televisions. As part of the expansion Nanosys expects to create more than 50 next-generation manufacturing jobs in the South Bay.

Nanosys’ latest product, Quantum Dot Enhancement Film (QDEF), is a drop-in optical component for LCDs that creates a richer, more lifelike color experience while consuming less power than alternatives. Nanosys is working closely with supply chain partner 3M to ramp deliveries as demand for QDEF from global display manufacturers increases.

"You’ve never seen anything like a quantum dot display," said Jason Hartlove, President and CEO of Nanosys. "We are working with display makers to create a new high color gamut display experience that is more cost effective, efficient and reliable than anything else currently on the market. The response from manufacturers so far has been great and demand for QDEF has grown to the point that we’ve had to significantly expand manufacturing to keep up."

The move was made official yesterday at a ribbon cutting ceremony attended by U.S. Congressman and long-time nanotechnology advocate Mike Honda of the 17th district and Milpitas Mayor Jose Esteves.

"Advanced manufacturing is a driving force creating Silicon Valley jobs, and I welcome Nanosys Inc.’s expansion to their new 60,000 square foot manufacturing facility in Milpitas," said Silicon Valley Congressman Mike Honda.  "As my Blue Ribbon Task Force on Nanotechnology made clear, nanotechnology offers Silicon Valley the opportunity to be at the forefront of technologically disruptive industries.  I applaud Nanosys for displaying the fortitude and ingenuity to grow from a startup to manufacturing commercial products, qualities that are so prevalent in Silicon Valley.  It is this kind of innovation that will keep the United States competitive in the global marketplace."

A year ago, the microtechnology, nanotechnology, and advanced materials industry looked out on the year 2012 with quite positive expectations. As it turned out, the unstable economic situation has left its mark on these industries, too. For 2013, at least, the companies expect a slight upwards trend.

At present, the mood of the industry is quite subdued, as the economic data survey of the IVAM Microtechnology Network confirms. In 2012, the business situation has been worse than expected in a third of companies. While orders and staff numbers have slightly risen and production has remained stable for a large proportion of companies, sales figures have dropped. The lack of funding for the strategic business development, expansion or investment in innovation is still an essential problem. Only 7 percent of companies had more funds available for corporate financing in 2012 than in the year before, only 16 percent have been able to invest more than in 2011.

Foreign trade has developed modestly in the last business year, thus continuing the trend of previous years. Throughout Europe, the export rates of the microtechnology, nanotechnology and advanced materials industry have remained rather stable in 2012.

In order to be able to compete the companies will attempt to enter the markets also via subsidiaries or cooperation. Markets of particular interest are the BRIC countries as well as countries that have recently been reclassified from emerging markets to industrial nations. Brazil, Russia, India and China as well as Israel, Taiwan and South Korea are countries which the companies want to enter in the short and medium term, e.g. by cooperative ventures or setting up branches.

In the European microtechnology industry, the business situation in 2012 has been worse than expected in a third of companies.

Imagine if you could drink a glass of water just by inserting a solid wire into it and sucking on it as though it were a soda straw. It turns out that if you were tiny enough, that method would work just fine — and wouldn’t even require the suction to start.

New research carried out at MIT and elsewhere has demonstrated for the first time that when inserted into a pool of liquid, nanowires — wires that are only hundreds of nanometers across — naturally draw the liquid upward in a thin film that coats the surface of the wire. The finding could have applications in microfluidic devices, biomedical research and inkjet printers.

The phenomenon had been predicted by theorists, but never observed because the process is too small to be seen by optical microscopes; electron microscopes need to operate in a vacuum, which would cause most liquids to evaporate almost instantly. To overcome this, the MIT team used an ionic liquid called DMPI-TFSI, which remains stable even in a powerful vacuum. Though the observations used this specific liquid, the results are believed to apply to most liquids, including water.

The results are published in the journal Nature Nanotechnology by a team of researchers led by Ju Li, an MIT professor of nuclear science and engineering and materials science and engineering, along with researchers at Sandia National Laboratories in New Mexico, the University of Pennsylvania, the University of Pittsburgh, and Zhejiang University in China.

While Li says this research intended to explore the basic science of liquid-solid interactions, it could lead to applications in inkjet printing, or for making a lab on a chip. “We’re really looking at fluid flow at an unprecedented small length scale,” Li says — so unexpected new phenomena could emerge as the research continues.

At molecular scale, Li says, “the liquid tries to cover the solid surface, and it gets sucked up by capillary action.” At the smallest scales, when the liquid forms a film less than 10nm thick, it moves as a smooth layer (called a “precursor film”); as the film gets thicker, an instability (called a Rayleigh instability) sets in, causing droplets to form, but the droplets remain connected via the precursor film. In some cases, these droplets continue to move up the nanowire, while in other cases the droplets appear stationary even as the liquid within them flows upward.

The difference between the smooth precursor film and the beads, Li says, is that in the thinner film, each molecule of liquid is close enough to directly interact, through quantum-mechanical effects, with the molecules of the solid buried beneath it; this force suppresses the Rayleigh instability that would otherwise cause beading. But with or without beading, the upward flow of the liquid, defying the pull of gravity, is a continuous process that could be harnessed for small-scale liquid transport.

Although this upward pull is always present with wires at this tiny scale, the effect can be further enhanced in various ways: Adding an electric voltage on the wire increases the force, as does a slight change in the profile of the wire so that it tapers toward one end. The researchers used nanowires made of different materials — silicon, zinc oxide and tin oxide, as well as two-dimensional graphene — to demonstrate that this process applies to many different materials.

Nanowires are less than one-tenth the diameter of fluidic devices now used in biological and medical research, such as micropipettes, and one-thousandth the diameter of hypodermic needles. At these small scales, the researchers found, a solid nanowire is just as effective at holding and transferring liquids as a hollow tube. This smaller scale might pave the way for new kinds of microelectromechanical systems to carry out research on materials at a molecular level.

The methodology the researchers developed allows them to study the interactions between solids and liquid flow “at almost the smallest scale you could define a fluid volume, which is 5 to 10 nanometers across,” Li says. The team now plans to examine the behavior of different liquids, using a “sandwich” of transparent solid membranes to enclose a liquid, such as water, for examination in a transmission electron microscope. This will allow “more systematic studies of solid-liquid interactions,” Li says — interactions that are relevant to corrosion, electrodeposition and the operation of batteries.

The research was supported by Sandia National Laboratories, the U.S. Department of Energy, and the National Science Foundation.