Tag Archives: IBM Research

Transforming electronics with metal-breathing bacteria

‘Metal-breathing’ bacteria, eh? A July 28, 2020 news item on Nanowerk announces the research into new materials for electronics (Note: A link has been removed),

When the Shewanella oneidensis bacterium “breathes” in certain metal and sulfur compounds anaerobically, the way an aerobic organism would process oxygen, it produces materials that could be used to enhance electronics, electrochemical energy storage, and drug-delivery devices.

The ability of this bacterium to produce molybdenum disulfide – a material that is able to transfer electrons easily, like graphene – is the focus of research published in Biointerphases (“Synthesis and characterization of molybdenum disulfide nanoparticles in Shewanella oneidensis MR-1 biofilms”) by a team of engineers from Rensselaer Polytechnic Institute.

A July 28, 2020 Rensselaer Polytechnic Institute (RPI) news release (also on EurekAlert) by Torie Wells, which originated the news item, describes the work in more detail,

“This has some serious potential if we can understand this process and control aspects of how the bacteria are making these and other materials,” said Shayla Sawyer, an associate professor of electrical, computer, and systems engineering at Rensselaer.

The research was led by James Rees, who is currently a postdoctoral research associate under the Sawyer group in close partnership and with the support of the Jefferson Project at Lake George — a collaboration between Rensselaer, IBM Research, and The FUND for Lake George that is pioneering a new model for environmental monitoring and prediction. This research is an important step toward developing a new generation of nutrient sensors that can be deployed on lakes and other water bodies.

“We find bacteria that are adapted to specific geochemical or biochemical environments can create, in some cases, very interesting and novel materials,” Rees said. “We are trying to bring that into the electrical engineering world.”

Rees conducted this pioneering work as a graduate student, co-advised by Sawyer and Yuri Gorby, the third author on this paper. Compared with other anaerobic bacteria, one thing that makes Shewanella oneidensis particularly unusual and interesting is that it produces nanowires capable of transferring electrons [emphasis mine].

“That lends itself to connecting to electronic devices that have already been made,” Sawyer said. “So, it’s the interface between the living world and the manmade world that is fascinating.”

Sawyer and Rees also found that, because their electronic signatures can be mapped and monitored, bacterial biofilms could also act as an effective nutrient sensor that could provide Jefferson Project researchers with key information about the health of an aquatic ecosystem like Lake George.

“This groundbreaking work using bacterial biofilms represents the potential for an exciting new generation of ‘living sensors,’ which would completely transform our ability to detect excess nutrients in water bodies in real-time. This is critical to understanding and mitigating harmful algal blooms and other important water quality issues around the world,” said Rick Relyea, director of the Jefferson Project.

Sawyer and Rees plan to continue exploring how to optimally develop this bacterium to harness its wide-ranging potential applications.

“We sometimes get the question with the research: Why bacteria? Or, why bring microbiology into materials science?” Rees said. “Biology has had such a long run of inventing materials through trial and error. The composites and novel structures invented by human scientists are almost a drop in the bucket compared to what biology has been able to do.”

Here’s a link to and a citation for the paper,

Synthesis and characterization of molybdenum disulfide nanoparticles in Shewanella oneidensis MR-1 biofilms by James D. Rees, Yuri A. Gorby, and Shayla M. Sawyer. Biointerphases 15, 041006 (2020) DOI: https://doi.org/10.1116/6.0000199 Published Online: 24 July 2020

This paper is behind a paywall.

Nanodiamonds as imaging devices

Two different teams have recently published studies in Science magazine (Feb. 1, 2013 issue) about their work with nanodiamonds, flaws, and imaging in what seems to be a case of synchronicity as there are no obvious connections between the teams.

Sabrina Richards writes in her Jan. 31, 2013 article for The Scientist about the possibility of taking snapshots of molecules at some time in the future (Note: Links have been removed),

A miniscule diamond flaw—just two atoms different—could someday enable researchers to image single molecules without resorting to time-consuming and technically exacting X-ray crystallography. The new approach, published today (January 31 [sic]) in Science, relies on a single electron to detect perturbation in molecular magnetic fields, which can provide clues about the structures of proteins and other molecules.

The work was inspired by magnetic resonance imaging (MRI), which uses electromagnetic coils to detect the magnetic fields emitted by hydrogen atom protons.  But traditional MRI requires many trillions of protons to get a clear image—of a brain, for example—preventing scientists from visualizing anything much smaller than millimeters-wide structures. To detect just a few protons, such as those of a single molecule, scientists would need an atomic-scale sensor.

To construct such a sensor, physicists Daniel Rugar at IBM Research and David Awschalom at the University of California, Santa Barbara, turned to diamonds. A perfect diamond, made entirely of carbon atoms covalently bonded to each other, has no free electrons and therefore no magnetic properties, explained Hammel. But a special kind of defect, known as a nitrogen-vacancy (NV) center, confers unique magnetic properties.

Jyllian Kemsley’s Jan. 31, 2013 article for C&EN (Chemical and Engineering News) discusses the work from both teams and describes the technique they used,

To downscale NMR [aka MRI], both groups used a detector made of diamond with a site defect called a single nitrogen-vacancy (NV) center, in which a nitrogen atom and a lattice hole replace two adjacent carbon atoms. Prior work had determined that NV centers are sensitive to the internal magnetic fields of the diamond. The new research demonstrates that the fluorescence of such centers can be used to detect magnetic fields emanating from just outside the diamond. Both groups were able to use NV centers to detect nuclear polarization of hydrogens in poly(methyl methacrylate) with a sample volume lower limit of about (5 nm)3. Further development is necessary to extract structural information.

Still, nothing much has happened with this technique as Richards notes in her article,

So far, the study is “just a proof of principle,” noted Awschalom. The researchers haven’t actually imaged any molecules yet, but simply detected their presence. Still, Awschalom said, “we’ve shown it’s not a completely ridiculous idea to detect external nuclear magnetic fields with one electron.” …

Here’s a citation and a link to the article,

Nanoscale Nuclear Magnetic Resonance with a Nitrogen-Vacancy Spin Sensor by H. J. Mamin, M. Kim, M. H. Sherwood, C. T. Rettner, K. Ohno, D. D. Awschalom, D. Rugar. Science 1 February 2013: Vol. 339 no. 6119 pp. 557-560 DOI: 10.1126/science.1231540

The other research is described in a Feb. 14, 2013 news item on Azonano,

Magnetic resonance imaging (MRI) reveals details of living tissues, diseased organs and tumors inside the body without x-rays or surgery. What if the same technology could peer down to the level of atoms? Doctors could make visual diagnoses of a person’s molecules – examining damage on a strand of DNA, watching molecules misfold, or identifying a cancer cell by the proteins on its surface.

It is remarkably  similar work as Kemsley notes not helped by the fact that the one line description for both articles in Science magazine’s Table of Contents is identical.  (One line description: The optical response of the spin of a near-surface atomic defect in diamond can be used to sense proton magnetic fields.) The City College of New York City Feb. 13, 2013 news release, which originated the Azonano news item about the other team, offers more details,

 … Dr. Carlos Meriles, associate professor of physics at The City College of New York, and an international team of researchers at the University of Stuttgart and elsewhere have opened the door for nanoscale MRI. They used tiny defects in diamonds to sense the magnetic resonance of molecules. They reported their results in the February 1 [2013] issue of Science.

“It is bringing MRI to a level comparable to an atomic force microscope,” said Professor Meriles, referring to the device that traces the contours of atoms or tugs on a molecule to measure its strength. A nanoscale MRI could display how a molecule moves without touching it.

“Standard MRI typically gets to a resolution of 100 microns,” about the width of a human hair, said Professor Meriles. “With extraordinary effort,” he said, “it can get down to about 10 microns” – the width of a couple of blood cells. Nanoscale MRI would have a resolution 1,000 to 10,000 times better.

To try to pick up magnetic resonance on such a small scale, the team took advantage of the spin of protons in an atom, a property usually used to investigate quantum computing. In particular, they used minute imperfections in diamonds.

Diamonds are crystals made up almost entirely of carbon atoms. When a nitrogen atom lodges next to a spot where a carbon atom is missing, however, it creates a defect known as a nitrogen-vacancy (NV) center.

“These imperfections turn out to have a spin – like a little compass – and have some remarkable properties,” noted Professor Meriles. In the last few years, researchers realized that these NV centers could serve as very sensitive sensors. They can pick up the magnetic resonance of nearby atoms in a cell, for example. But unlike the atoms in a cell, the NVs shine when a light is directed at them, signaling what their spin is. If you illuminate it with green light it flashes red back.

“It is a form of what is called optically detected magnetic resonance,” he said. Like a hiker flashing Morse code on a hillside, the sensor “sends back flashes to say it is alive and well.”

“The NV can also be thought of as an atomic magnet. You can manipulate the spin of that atomic magnet just like you do with MRI by applying a radio frequency or radio pulses,” Professor Meriles explained. The NV responds. Shine a green light at it when the spin is pointing up and it will respond with brighter red light. A down spin gives a dimmer red light.

In the lab, graduate student Tobias Staudacher — the first author in this work — used NVs that had been created just below the diamond’s surface by bombarding it with nitrogen atoms. The team detected magnetic resonance within a film of organic material applied to the surface, just as one might examine a thin film of cells or tissue.

“Ultimately,” said Professor Meriles, “One will use a nitrogen-vacancy mounted on the tip of an atomic force microscope – or an array of NVs distributed on the diamond surface – to allow a scanning view of a cell, for example, to probe nuclear spins with a resolution down to a nanometer or perhaps better.”

Here’s a citation and a link to this team’s study,

Nuclear Magnetic Resonance Spectroscopy on a (5-Nanometer)3 Sample Volume by T. Staudacher, F. Shi, S. Pezzagna, J. Meijer, J. Du, C. A. Meriles, F. Reinhard1, J. Wrachtrup. Science 1 February 2013: Vol. 339 no. 6119 pp. 561-563 DOI: 10.1126/science.1231675

Both articles are behind paywalls.

Germany goes international with SpinNet, its spintronics project

A Feb. 8, 2013 news item on Nanowerk features an announcement of an international spintronics project, SpinNet, being funded by the federal government of Germany,

The German Academic Exchange Service (DAAD) is sponsoring a joint project involving Johannes Gutenberg University Mainz (JGU) in Mainz, Tohoku University in Japan, Stanford University, and IBM Research. The project will be focusing on the field of spintronics, a key technology that enables the creation of new energy-efficient IT devices. At Mainz researchers from JGU’s Institute of Physics and the Institute of Inorganic Chemistry and Analytical Chemistry participate with many of the activities taking place under the Materials Science in Mainz (MAINZ) Graduate School of Excellence. Over the next four years, the SpinNet network will be funded with about EUR 1 million from the German Federal Ministry of Education and Research (BMBF). SpinNet is one of the 21 projects that the German Academic Exchange Service approved from the total of 120 proposals submitted in the first round and from the 40 entries that made it to the second round.

The Johannes Gutenberg-Universität Mainz (Mainz University) Feb. 8, 2013 news release, which originated the news item, provides details about the network and about the project itself,

Under the aegis of the MAINZ Graduate School, Johannes Gutenberg University Mainz had submitted a proposal for financial support as a so-called “Thematic Network”. With this program, the German Academic Exchange Service aims to provide support to research-based multilateral and international networks with leading partners from abroad. The inclusion of non-university research facilities, such as IBM Research, was encouraged and the program is intended to help create attractive conditions that will help attract excellent international young researchers from partner universities to Germany. Another purpose is to enable the participating German universities to work at the cutting edge of international research by creating centers of competence. The MAINZ Graduate School has been closely cooperating with the partners for years and SpinNet will help to further this cooperation and fund complementary activities.

SpinNet will concentrate on the development of energy-saving information technology using the potential provided by spintronics. The current semiconductor-based systems will reach their limits in the foreseeable future, meaning that innovative technologies need to be developed if components are to be miniaturized further and energy consumption is reduced. In this context, spintronics is a highly promising approach. While conventional electronic systems in IT components employ only the charge of electrons, spintronics also involves the intrinsic angular momentum or spin of electrons for information processing. Using this technology, it should be possible to develop non-volatile storage and logic systems and these would then reduce energy consumption while also radically simplifying systems architecture. The new research network will be officially launched on April 1, 2013; with the inaugural meeting of the partners taking place at the Newspin3 Conference that is to be held on April 2-4, 2013 in Mainz.

You can find more information and videos about this initiative and/or spintronics by clicking the news item link or news release link.  There does not seem to be a SpinNet website. NewsSpin3 conference information can be found here along with details about the NewSpin3 summer school which takes place immediately following the conference. Spintronics was last mentioned here in a Jan. 31, 2013 posting about a 3-D microchip developed from a spintronics chip.