Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Researchers develop new method to control nanoscale diamond sensors: Technique allows tiny sensors to monitor small changes in magnetic fields, such as when neurons transmit electrical signals.

A single nitrogen-vacancy (N-V) center in diamond (right, inset), optically initialized and readout by confocal microscopy, is manipulated with coherent control sequences (red line) of microwave pulses. This measures the arbitrary profile of time-varying magnetic fields radiated by biological sources (or by artificial sources in the researchers' proof-of-principle experiment).
Image: Paola Cappellaro courtesy the researchers
A single nitrogen-vacancy (N-V) center in diamond (right, inset), optically initialized and readout by confocal microscopy, is manipulated with coherent control sequences (red line) of microwave pulses. This measures the arbitrary profile of time-varying magnetic fields radiated by biological sources (or by artificial sources in the researchers' proof-of-principle experiment).

Image: Paola Cappellaro courtesy the researchers

Abstract:
Diamonds may be a girl's best friend, but they could also one day help us understand how the brain processes information, thanks to a new sensing technique developed at MIT.

Researchers develop new method to control nanoscale diamond sensors: Technique allows tiny sensors to monitor small changes in magnetic fields, such as when neurons transmit electrical signals.

Cambridge, MA | Posted on January 24th, 2014

A team in MIT's Quantum Engineering Group has developed a new method to control nanoscale diamond sensors, which are capable of measuring even very weak magnetic fields. The researchers present their work this week in the journal Nature Communications.

The new control technique allows the tiny sensors to monitor how these magnetic fields change over time, such as when neurons in the brain transmit electrical signals to each other. It could also enable researchers to more precisely measure the magnetic fields produced by novel materials such as the metamaterials used to make superlenses and "invisibility cloaks."

In 2008 a team of researchers from MIT, Harvard University, and other institutions first revealed that nanoscale defects inside diamonds could be used as magnetic sensors.

The naturally occurring defects, known as nitrogen-vacancy (N-V) centers, are sensitive to external magnetic fields, much like compasses, says Paola Cappellaro, the Esther and Harold Edgerton Associate Professor of Nuclear Science and Engineering (NSE) at MIT.

Defects inside diamonds are also known as color centers, Cappellaro says, as they give the gemstones a particular hue: "So if you ever see a nice diamond that is blue or pink, the color is due to the fact that there are defects in the diamond."

The N-V center defect consists of a nitrogen atom in place of a carbon atom and next to a vacancy or hollow within the diamond's lattice structure. Many such defects within a diamond would give the gemstone a pink color, and when illuminated with light they emit a red light, Cappellaro says.

To develop the new method of controlling these sensors, Cappellaro's team first probed the diamond with green laser light until they detected a red light being emitted, which told them exactly where the defect was located.

They then applied a microwave field to the nanoscale sensor, to manipulate the electron spin of the N-V center. This alters the intensity of light emitted by the defect, to a degree that depends not only on the microwave field but also on any external magnetic fields present.

To measure external magnetic fields and how they change over time, the researchers targeted the nanoscale sensor with a microwave pulse, which switched the direction of the N-V center's electron spin, says team member and NSE graduate student Alexandre Cooper. By applying different series of these pulses, acting as filters each of which switched the direction of the electron spin a different number of times the team was able to efficiently collect information about the external magnetic field.

They then applied signal-processing techniques to interpret this information and used it to reconstruct the entire magnetic field. "So we can reconstruct the whole dynamics of this external magnetic field, which gives you more information about the underlying phenomena that is creating the magnetic field itself," Cappellaro says.

The team used a square of diamond three millimeters in diameter as their sample, but it is possible to use sensors that are only tens of nanometers in size. The diamond sensors can be used at room temperature, and since they consist entirely of carbon, they could be injected into living cells without causing them any harm, Cappellaro says.

One possibility would be to grow neurons on top of the diamond sensor, to allow it to measure the magnetic fields created by the "action potential," or signal, they produce and then transmit to other nerves.

Previously, researchers have used electrodes inside the brain to "poke" a neuron and measure the electric field produced. However, this is a very invasive technique, Cappellaro says. "You don't know if the neuron is still behaving as it would have if you hadn't done anything," she says.

Instead, the diamond sensor could measure the magnetic field noninvasively. "We could have an array of these defect centers to probe different locations on the neuron, and then you would know how the signal propagates from one position to another one in time," Cappellaro says.

In experiments to demonstrate their sensor, the team used a waveguide as an artificial neuron and applied an external magnetic field. When they placed the diamond sensor on the waveguide, they were able to accurately reconstruct the magnetic field. Mikhail Lukin, a professor of physics at Harvard, says the work demonstrates very nicely the ability to reconstruct time-dependent profiles of weak magnetic fields using a novel magnetic sensor based on quantum manipulation of defects in diamond.

"Someday techniques demonstrated in this work may enable us to do real-time sensing of brain activity and to learn how they work," says Lukin, who was not involved in this research. "Potential far-reaching implications may include detection and eventual treatment of brain diseases, although much work remains to be done to show if this actually can be done," he adds.

####

For more information, please click here

Copyright © Massachusetts Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Personal cooling units on the horizon April 29th, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Brain-Computer Interfaces

Physicists build 'electronic synapses' for neural networks April 21st, 2016

Graphene shown to safely interact with neurons in the brain January 31st, 2016

Tiny electronic implants monitor brain injury, then melt away January 19th, 2016

UCLA scientists create graphene barrier to precisely control molecules for making nanoelectronics January 19th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Personal cooling units on the horizon April 29th, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

Nanomedicine

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

Sensors

Electrically Conductive Graphene Ink Enables Printing of Biosensors April 23rd, 2016

Highlights from the Graphene Flagship April 22nd, 2016

Team builds first quantum cascade laser on silicon: Eliminates the need for an external light source for mid-infrared silicon photonic devices or photonic circuits April 21st, 2016

With simple process, UW-Madison engineers fabricate fastest flexible silicon transistor April 21st, 2016

Discoveries

Personal cooling units on the horizon April 29th, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

Announcements

Personal cooling units on the horizon April 29th, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Personal cooling units on the horizon April 29th, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Quantum nanoscience

The atom without properties April 22nd, 2016

Changing the color of single photons in a diamond quantum memory April 7th, 2016

New state of matter detected in a two-dimensional material April 6th, 2016

Scientists divide magnetic vortices into collectivists and individualists April 3rd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic