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Physics and Electro-Optics

Category
Technology Name
Briefcase
Scientist
1815
This novel method utilizes polarized light that in contrast to conventional methods does not interact directly with the material or with the material’s surface. Here the material to be tested is secured underneath a reflective material, such that the polarized light reflected off the reflective...

This novel method utilizes polarized light that in contrast to conventional methods does not interact directly with the material or with the material’s surface. Here the material to be tested is secured underneath a reflective material, such that the polarized light reflected off the reflective material does not interact with the sample itself. Accordingly, the polarized light is only affected by expansion/contraction of the material that displaces the reflective material, but is not affected by material’s properties such as refractive index and surface-layer composition/thickness. The novel methods of this invention thus allow the isolation of expansion/contraction parameters of a material. Accordingly, the methods of this invention allow facile, fast and accurate measurement of expansion/contraction properties of a material using polarized light.

Applications


Measuring the expansion/contraction of materials for the evaluation of qualitative and quantitative electro-mechanic properties (e.g. piezo-electric parameters) and thermal expansion properties of materials using a sensitive and non-complex system.


Advantages


·      Relatively simple and inexpensive

·      High sensitivity - comparable to extremely complex and expensive interferometers

·      Supports a higher frequency range than existing interferometers.


Technology's Essence


Here the material to be tested is secured underneath a reflective material, such that the polarized light reflected off the reflective material does not interact with the sample itself. Accordingly, the polarized light is only affected by expansion/contraction of the material that displaces the reflective material, but is not affected by material’s properties such as refractive index and surface-layer composition/thickness.

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  • Prof. Igor Lubomirsky
1795
Ultra-thin endoscopes are highly desirable for many applications involving remote imaging. Current ultra-thin endoscopes are primarily video-endoscopes and have a shaft diameter of 6 mm or less. Fiberscopes, on the other hand, can reach a micro-meter diameter, thus allowing examination of small,...

Ultra-thin endoscopes are highly desirable for many applications involving remote imaging. Current ultra-thin endoscopes are primarily video-endoscopes and have a shaft diameter of 6 mm or less. Fiberscopes, on the other hand, can reach a micro-meter diameter, thus allowing examination of small, difficult-to-reach, spaces for medical and other applications. Multimode fibers are being explored as ultra-thin lensless replacements for the commonly used endoscopes. The difficulty with imaging or focusing light through a multimode fiber is phase randomization of light propagating through the fiber, which results in a complex speckle pattern at the fiber output. To overcome this obstacle, an access to both fiber ends is required for pre-calibration.

A novel endoscopic method that was developed by Prof. Silberberg at the Weizmann Institute of Science allows light focusing through a multimode fiber by approaching solely the proximal end and retrieving information about the distal end using non-linear optical feedback.

Applications


·         Clinical imaging of narrow cavities (blood vessels, respiratory system, joints, etc.)

·         Selective targeting and burning of fluorescent targets (imaging and treatment)  


Advantages


  • Ultra-thin (micro-meter scale) and flexible

  • Lensless endoscopy

  • High resolution and accuracy


Technology's Essence


We consider a two-photon lensless multimode fiber-based endoscope, where an ultrashort pulse is delivered to a fluorescently tagged sample through the fiber. The pulses excite two photon fluorescence (2PF) from a 2PF screen placed against the fiber distal end. The back-propagated 2PF that is collected by the same fiber is separated from the excitation light at the proximal end by a dichroic mirror (DM), and the Fourier-transformed image of the fiber facet is recorded by an EMCCD camera. It is then used as feedback for a wavefront-shaping optimization algorithm, controlling a spatial light modulator (SLM) at the proximal fiber end. The nature of the light propagation in the fiber allows for scanning and controlling the focus position at the fiber distal end.

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  • Prof. Yaron Silberberg
1780
A method based on Fast Neutron Resonance Transmission (FNRT) radiography that enables determining weight percentages of oil and water in thick, intact cores taken from subterranean or underwater geological formations. As part of geological exploitation to find oil and water, cores are extracted and...

A method based on Fast Neutron Resonance Transmission (FNRT) radiography that enables determining weight percentages of oil and water in thick, intact cores taken from subterranean or underwater geological formations. As part of geological exploitation to find oil and water, cores are extracted and tested to determine oil/water content.
This new method allows determining such content rapidly, in non- destructive, specific and quantities analysis of the cores.

Applications


  • Determining the identity and proportions of substances of oil and water content and their distribution in inspected cores

Advantages


  • A non-destructive method which enables to determine the fluid content along the entire length of an intact core or aggregate of cores within their protective sleeves.
  • More comprehensive information and considerable saving of analysis time compared to conventional sampling methods.
    Suitable for all types of rocks including tight-shale rocks.
  • This method enables to measure the weight fraction of oil and water in the core regardless of the core shape, thickness or distribution.
  • The fluid weight fractions in the samples are determined independently, thus the ratio of oil-to-rock weight-ratio is independent of the water content.
  • Due to high penetration of fast neutrons, the method is suitable for screening intact thick rock cores (10-15 cm), for which alternative probes, such as X-rays or slow neutrons suffer limited penetration.

Technology's Essence


In order to map the oil and water content and their distribution, an aggregate of intact cores within their protective sleeves is positioned on a moving conveyor belt and scanned by a broad- energy, fast- neutron beam. The neutrons are detected by a spectroscopic fast neutron imaging detector. The map of neutron-transmission spectra in each pixel provides information of oil/water content and distribution in such cores. 

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  • Prof. Amos Breskin
1717
Converting two low-energy photons into a single higher-energy photon is of significant importance in many fields. In medical imaging, photon up-conversion is used for imaging scattered specimens, while in photovoltaic devices it could be used to harvest photons with energies lower than the bandgap of...

Converting two low-energy photons into a single higher-energy photon is of significant importance in many fields. In medical imaging, photon up-conversion is used for imaging scattered specimens, while in photovoltaic devices it could be used to harvest photons with energies lower than the bandgap of the absorber.
Currently available systems, based on rare-earth-doped dielectrics, and organic materials are limited in both tunability and absorption cross-section. In fact, no known up-conversion systems operate on photons in the 1000-1500 nm range.
Stable inorganic nanocrystalline up-conversion systems designed at the Weizmann Institute of Science provide broad tunability of both the absorption edge and the luminescence color. These materials have the potential to be utilized in applications such as high-energy photon sources, photovoltaics and IR detection.

Applications


  • Easy to manufacture

  • Robust systems

  • Operation at room temperature


Advantages


  • Photon sources

  • Photovoltaics

  • IR detectors


Technology's Essence


The new up-conversion systems are based on a novel design comprising a compound semiconductor nanocrystal, which incorporates two quantum dots with different bandgaps separated by a tunneling barrier. The expected up-conversion mechanism occurs by the sequential absorption of two photons. The first photon excites an electron–hole pair by interband absorption in the lower-energy core, resulting in a confined hole and a relatively delocalized electron. The second absorbed photon leads to further excitation of the hole, allowing it to cross the barrier layer. This, in turn, is followed by radiative recombination with the delocalized electron.

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  • Prof. Dan Oron
1765
A new image reconstruction tool based on non-iterative phase information retrieval from a single diffraction pattern was developed by the group of Prof. Oron.  Lensless imaging techniques enable indirect high resolution observation of objects by measuring the intensity of their diffraction patterns....

A new image reconstruction tool based on non-iterative phase information retrieval from a single diffraction pattern was developed by the group of Prof. Oron. 
Lensless imaging techniques enable indirect high resolution observation of objects by measuring the intensity of their diffraction patterns. These techniques utilize radiation in the X-ray regime to image non-periodic objects in sizes that prohibit the use of larger wavelengths. However, retrieving the phase information of the diffraction pattern is not a trivial task, as current methods are divided based on a tradeoff between experimental complexity and computational reconstruction efficiency.
The method described here is suitable for use with existing lensless imaging techniques to provide direct, robust and efficient phase data while requiring reduced computational and experimental complexity. This method, demonstrated in a laboratory setup on 2D objects, is also applicable in 1D. It can be applied to various phase retrieval applications such as coherent diffractive imaging and ultrashort pulse reconstruction

Applications


  • Phase microscopy
  • Signal processing
  • Holography
  • X-ray imaging

Advantages


  • A Generic solution to the phase retrieval problem
  • Non-iterative approach
  • An efficient and noise robust tool

Technology's Essence


The method is based on the fact that the Fourier transform of the diffraction intensity measurement is the autocorrelation of the object. The autocorrelation and cross-correlations of two sufficiently separated objects are spatially distinct. Based on this, the method consists of three main steps: (a) The sum of the objects’ autocorrelations, as well as their cross-correlation, are reconstructed from the Fourier transform of the measured diffraction pattern. (b) The individual objects’ autocorrelations are reconstructed from their sum and the cross-correlation. (c) Using the two intensities and the interference cross term, double-blind Fourier holograph is applied to recover the phase by solving a set of linear equations.

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  • Prof. Dan Oron
1802
A new signal processing tool for the detection of pulses travelling through media with complex or unknown dispersion properties was developed by the group of Prof. Gal-Yam, originally for detecting radio bursts in astronomical observations. Pulses are applied in various fields such as oil & gas...

A new signal processing tool for the detection of pulses travelling through media with complex or unknown dispersion properties was developed by the group of Prof. Gal-Yam, originally for detecting radio bursts in astronomical observations.
Pulses are applied in various fields such as oil & gas exploration, detection (e.g. sonar, lidar and radar) and communication. When pulses pass through dispersive media, the arrival times at the detector of different frequency components may differ, and as a result the pulse may become degraded (e.g. transformed to a longer pulse with reduced intensity), even to the level of becoming indistinguishable in terms of signal to noise. This problem becomes even more challenging when detecting short pulses that travel through complex or unknown media.
The new method presented here provides a proven and efficient solution that can be applied for different scenarios where short pulses dispersed by complex media are used. 

Applications


  • Detection and surveying technologies- sonar, lidar, radar etc

Advantages


  • Efficient, requires limited computational resources
  • Generic, can be applied to various setups
  • Easily implementable into existing systems

Technology's Essence


The method includes obtaining an input array of cells, each indicating an intensity of a frequency component of the signal at a representative time. A fast dispersion measure transform (FDMT) is applied to concurrently sum the cells of the input array that lie along different dispersion curves, each curve defined by a known non-linear functional form and being uniquely characterized by a time coordinate and by a value of the dispersion measure. Application of FDMT includes initially generating a plurality of sub-arrays, each representing a frequency sub-band and iteratively combining pairs of adjacent sub-arrays in accordance with an addition rule until all of the initially generated plurality of sub-arrays are combined into an output array of the sums, in which a cell of the output array that is indicative of a transmitted pulse is identified.

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  • Prof. Avishay Gal-Yam
1696
A new method for observing large areas with physically small detectors, which are unable to cover the whole area simultaneously, based on multiplexing several scanned areas onto a single detector unit followed by algorithmic reconstruction of the true field of view. Astronomical observations require...

A new method for observing large areas with physically small detectors, which are unable to cover the whole area simultaneously, based on multiplexing several scanned areas onto a single detector unit followed by algorithmic reconstruction of the true field of view.
Astronomical observations require the ability to detect very weak signals at high spatial resolution. This reflects on the special characteristics of the observation systems; they need to have a large aperture, high resolution detectors and very low system noise. These demands render high costs and complexity.
Our multiplexing and reconstructing method was developed based on the sparse nature of astronomical observations, and it could be implemented in any application in which sporadic data points are to be found against a fixed (whether detailed or blank) background.

Applications


  • Highly efficient telescopes
  • Quick quality assurance systems – fault metrology
  • Implementation in microscopy

Advantages


  • Use of small size detectors
  • Ability to scan large fields (compared to detector size)
  • Maintaining high resolution
  • Significant shortening of scan time
  • Easily applicable to existing systems

Technology's Essence


The method was developed for astronomical observations in which the studied field is immense and the detector size is relatively small and limited. The invention consists of an optical system that directs light (IR, Vis, UV or other) from different locations in the sky to the focal plane of a telescope onto a specific single detector area, creating a multiplexed image in which several portions of the sky are presented collectively.
Such multiplexing is done on each detector unit area with a different set of sky loci.
A reconstruction algorithm was developed to construct sub-observations sets in a method that guarantees unique recovery of the original wide-field image even when objects overlap.

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  • Prof. Avishay Gal-Yam
1730
Production of carbon nanotube based transistors through a process comprised of identification, selection, and placement of pristine carbon nanotubes in conjunction with standard electrical circuitry.Semiconductor devices are vital to everyday life, however conventional semiconducting materials are...

Production of carbon nanotube based transistors through a process comprised of identification, selection, and placement of pristine carbon nanotubes in conjunction with standard electrical circuitry.
Semiconductor devices are vital to everyday life, however conventional semiconducting materials are quickly approaching their limitations. As devices transition from the microscale to the nanoscale, new techniques for their assembly and testing of their properties must be created. Controllable nanofabrication methods are of increasing importance across a wide field of electronics in everything from energy efficient LEDs in flat-screen monitors to transistors for ultra-powerful computers. Our process presents a novel method for producing high quality nanoscale carbon nanotube based transistors. These methods will be of the utmost importance in the forthcoming nano-revolution.

Applications


  • Produce flawless carbon nanotubes
  • Identify, select, and position nanotubes with precision
  • Room temperature operation
  • High sensitivity
  • High resolution

Advantages


  • Single electron transistor (SET) nanoscale imaging
  • Novel nano-electromechanical devices

Technology's Essence


The principle behind this technology is two-fold: 1) Synthesis and selection method of flawless carbon nanotubes, and 2) their combination with nanoscale electric circuitry to form fully controlled composite nanoscale electronic device.
Selection of the carbon nanotube(s) is assisted by a scanning probe microscope (SPM). A composite electronic device is assembled from two separated chips; a nanotube chip where nanotubes are grown over wide trenches, and a standard circuit chip with electrode contacts surrounding the gates to be measured. The nano-assembly is achieved by inserting an SPM cantilever into a trench on the nanotube chip and placing the circuit chip over a suitable nanotube. Once in place, the nanotube is cut locally by passing a strong current between the electrode contacts, and the composite chip is formed.
This composite electronic device can be used to map electronic potentials with high resolution of 100 nm, high sensitivity of 1microV/Hz1/2, at frequencies of 100 MHz and more and all this at room temperature.

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  • Prof. Shahal Ilani
1568
A new multi-state molecular building block for tomorrow’s electric circuits and memory storage devices was realized. Information technology is the core of many industries today. The main challenge facing this industry is the need for miniaturization, due to an ever increase in information density....

A new multi-state molecular building block for tomorrow’s electric circuits and memory storage devices was realized. Information technology is the core of many industries today. The main challenge facing this industry is the need for miniaturization, due to an ever increase in information density. Molecular information processing and storage is becoming a logical candidate to replace the available methods, by use of molecules as building blocks for “bottom up” approaches. A memory device that exists in multiple stable states with a molecular based assembly was prepared. This can offer new ways in which information is processed (multiple-threads) as well as increasing the information density in random access memory (RAM), storage devices and methods.

Applications


  • Binary and ternary Static Random Access Memory
  • Multi-State Dynamic Random Access Memory

  • Multi-State Flash Memory

  • Multi-State Solid State Drive (SSD)

  • Multi-State Information Processing Units


Advantages


  • Low manufacturing cost

  • Robustness

  • Optical read out allows fast data transfer, and non destructive information access

  • Short response time and fast read-out.

  • System is easy to reset

  • Little material is needed/ environmentally friendly.

  • The system can be integrated with other electronic circuits

  • Multi-valued information storage

  • Increase in information density, with no need for additional spatial requirements.

  • Alternative to silicon  technology


Technology's Essence


Electronically addressable multi-state memory for sequential logic flip-flop, flip-flap-flop circuits, and higher order switchable memory circuits,  can be constructed by materials composed of a molecular based assembly that can exist in multiple states. Since the optical output is a precise function of the applied voltage, multi-valued information can be written on to the assembly by applying specific potential biases. The read and write cycle is completed by monitoring the induced optical changes of the system. This system uses the same electrical inputs as conventional memory devices and uses an optical read-out which is non destructive and fast. The properties of the device can be used to create an apparatus for information storage especially with respect to developing solid-state drives in computers (SSDs).

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  • Prof. Milko E. Van der Boom
1596
A beam of light has several properties which can be measured for a variety of applications. The most commonly measured properties of light include Intensity, Color, Phase, and Polarization.In recent years there has been a growing demand to have well-defined optical beams. In order to accomplish this a...

A beam of light has several properties which can be measured for a variety of applications. The most commonly measured properties of light include Intensity, Color, Phase, and Polarization.In recent years there has been a growing demand to have well-defined optical beams. In order to accomplish this a light beam requires fast, accurate, and simple measurement techniques to fully characterize it’s properties.Currently, the ability to measure light polarization exists only qualitatively and at only one specific point in a light beam. Our scientific team has developed a new method to measure changing light polarizations in real-time. 
Our demonstrated system presents a simple way to continuously measure and quantify light polarizations in real-time, throughout the entire length of a light beam. This method has the potential to set a new industry standard, and could lead to a number of applications that were previously not possible.
 

Applications


  • Molecular imaging
  • Medical and industrial lasers
  • Non-destructive testing
  • Analytical chemistry
  • Fiber-optic communications
  • Cryptography
  • Astronomy

Advantages


  • Proved accuracy
  • Simple technique
  • Compact configuration
  • Incorporate into existing equipment
  • Can measure fully polarized, partially polarized, and un-polarized light
  • Two modes of operation:   Space-variant polarization measurements and Wavelength-variant polarization measurements

Technology's Essence


Our polarization measurement technique is based on splitting an input light beam into six parallel beams, each having a predetermined shift in the polarization state with respect to the other beams. The beam components are simultaneously detected using a pixel matrix, such as a CCD camera, to determine their intensity distribution. From this, the polarization state distribution along the cross-section of the input optical beam is determined and we can calculate the Stokes parameters, a set of values which defines polarized light. This allows us to characterize and quantify fully polarized, partially polarized, and un-polarized light at every point in the beam in real-time, with either static or dynamic polarization states. Our method can be applied for two conditions of varying polarizations – changing with position (space-variant) or changing in color (wavelength-variant).

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  • Prof. Nir Davidson
1644
Computer memory and storage are among the most critical components of today’s consumer electronics and computer technology. Currently available memory and storage technologies have inherent limitations that confine the capacity and speed of access to memory devices. The present innovation is based on...

Computer memory and storage are among the most critical components of today’s consumer electronics and computer technology. Currently available memory and storage technologies have inherent limitations that confine the capacity and speed of access to memory devices.

The present innovation is based on Chiral Induced Spin Selectivity (CISS) effect that was established experimentally and theoretically in the last decade, and allows for production of inexpensive, high-density universal memory-on-chip devices, that don’t require the use of permanent magnets.

Applications


·         Inexpensive, high-density universal memory-on-chip devices

·         The technology can be used as superior alternative for both Random Access memory and Flash memory

·         Surface-controlled spintronic devices

·         Logic and data processing


Advantages


·         Up to 70 times more storage on the same physical size

·         Up to 100 times lower energy consumption

·         Si-Compatible

·         High density (can reach Si technology limit)

·         Estimated low cost

·         Overcomes limitations of other magnetic-based memory technologies


Technology's Essence


Ferromagnets can be magnetized either by external magnetic fields or by spin polarized current. However, the current density required for inducing magnetization is extremely high and significantly affects the device’s structure and performance. The newly discovered CISS effect allows for magnetization switching of Ferromagnets, which is induced solely by adsorption of chiral molecules, where much lower current density is sufficient to induce the magnetization reversal. Chiral Memory technology uses the CISS effect for spin selectivity instead of the common ferromagnetic-based spin filters. This allows, in principle, the memory bit to be miniaturized down to a single magnetic nanoparticle or a nano-scale domain. The operation principle of the device relies on the spin-selective transmission of electrons through organic chiral molecules to the ferromagnetic layer of the device, which results in the magnetization of this layer and efficient storing of bits of information. The magnetization switching by local adsorption of chiral molecules eliminates the need for a permanent magnet.

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  • Prof. Ron Naaman
1554
We present a novel approach resulting in efficient and robust wireless energy transfer in the mid-range. Applications of wireless energy transfer are already in use and are continuously being developed. The main limit of wireless energy transfer techniques is that both the transmitter and transformer...

We present a novel approach resulting in efficient and robust wireless energy transfer in the mid-range. Applications of wireless energy transfer are already in use and are continuously being developed. The main limit of wireless energy transfer techniques is that both the transmitter and transformer need to be of the same resonance. In addition, this technique is very susceptible to noise which limits efficiency. The present invention provides a technique for a robust and efficient mid-range wireless power transfer between two coils. This technique can transfer the energy between the coils without being sensitive to any resonant constrains, noise and other interferences that exist in the neighborhood of the coils

Applications


  • Simultaneous energy transfer to several electrical gadgets.

Advantages


  • Efficient
  • Not sensitive to electrical interference.
  • No need for an exact resonance match between transmitter and transformer.

Technology's Essence


The efficiency and robustness of this technology is achieved by adapting the process of rapid adiabatic passage (RAP) for a coherently driven two state atom to the field of wireless energy transfer. In other words, the resonance of the transmitter is tuned adiabatically to scan a resonant frequency range, thus arriving at a dynamic solution to the electrical transfer problem.

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  • Prof. Yaron Silberberg
1583
The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. Thermoelectric effects are used in various applications, where heat energy is saved, that would be otherwise lost. Although the TE conversion efficiency is nowadays low (5-8%), the novel...

The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. Thermoelectric effects are used in various applications, where heat energy is saved, that would be otherwise lost. Although the TE conversion efficiency is nowadays low (5-8%), the novel technique developed at Weizmann Institute, has a disruptive potential to change this market.  

Prof. Y. Imry and his team at Weizmann Institute came up with Thermal Electric conversion technique, based on a new TE device architecture which allows performance enhancement. The core invention is in the field of Bi-junction thermoelectric device architecture, having a thermoelectric gate interposed between two electric regions, leading to thermal electric conversion efficiency optimization.

Applications


Various TE devices will benefit from better TE efficiency, achieved by the developed conversion technique. The growing market for thermoelectric energy harvesters will reach $865 million by 2023. Current TE market is driven by consumer energy harvesting applications and some niche segments:

  •  Automotive energy harvesting applications, since around 40% of the energy produced by internal combustion engines is currently lost in heat through the exhaust.
  • Wireless devices/sensors segment is forecasted to account for over a third of the overall market for thermoelectric harvesters and cooling by 2023.

Advantages


In order to drive down the thermoelectric module costs and facilitate broad deployment, TE has several barriers to overcome: 

  •  low conversion efficiency;
  • toxicity and low availability of chemical elements constituting part of the thermoelectric materials.

 In this context, the main TE market challenges are reaching higher efficiencies using low cost thermoelectric materials. These challenges can be addressed by the proposed technology.


Technology's Essence


Prof. Y. Imry and his team at Weizmann Institute have developed novel bi-junction TE device, having a thermoelectric gate interposed between two electric regions, aiming at TE efficiency improvement. Thermoelectric efficiency depends on the figure of merit (ZT). The figure-of-merit curves, for the developed 3-T TE device configurations show that higher ZT should be achieved.  

The secret essence of the invented configuration is in using two independently adjustable input parameters - voltage and temperature - as drivers for optimizing device thermoelectric efficiency.

 

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  • Prof. Yoseph Imry
1597
Metal-oxide material generates electromechanical stress an order of magnitude above existing materials.The ability to develop a mechanical stress in response to the application of an external electric field has many uses, and characteristic materials are classified as either piezoelectric or...

Metal-oxide material generates electromechanical stress an order of magnitude above existing materials.The ability to develop a mechanical stress in response to the application of an external electric field has many uses, and characteristic materials are classified as either piezoelectric or electrostrictive. Modern inorganic piezoelectric devices are used for a wide variety of applications from inexpensive speakers and headphones, to sophisticated sonar transducers. Over the last several decades, these materials have become highly reliable and technologically mature, but the magnitude of the mechanical stress they can generate in response to an input electric signal has reached an upper limit.This innovative technology applies Gadolinium-doped Cerium Oxide (Gd-doped CeO2) to piezoelectric and electrostrictive devices and will enable high-performance electromechanical materials with output capabilities an order of magnitude above existing solutions, in excess of 500 MPa. This could facilitate the next generation of many consumer and industrial electronic devices.

Applications


  • Wide range of personal electronic devices
  • Industrial and fine electronics – specifically powerful acoustic transducers

Advantages


  • Generate large displacement and large stress simultaneously
  • Sensitive and tunable properties

Technology's Essence


In piezoelectric devices, stress develops due to the deformation of a non-centrosymmetric lattice under the application of an electric field. In commercial electrostrictors, or materials with centrosymmetric lattices and very large dielectric constants, an external electric field distorts the unit cells of the lattice, rendering them locally non-centrosymmetric. In both cases, the electromechanical stress develops due to a small displacement of atoms within each unit cell. Increasing the magnitude of the response would lead to more powerful actuators, and permit a decrease in the operating voltage; therefore, the search for novel mechanisms of electromechanical response in solids remains an important objective for both fundamental and applied science.

We have demonstrated that Gd-doped CeO2, specifically Ce0.8Gd0.2O1.9, can generate stress an order of magnitude greater than the best electromechanically active materials. The large stress develops in response to the rearrangement of cerium-oxygen vacancy pairs and their local environment. This effect is expected to be two-fold; i) an applied electric field results in strain and stress directly, and ii) application of the external electric field affects the elastic modulus of Ce0.8Gd0.2O1.9 by suppressing the chemical strain effect. This is a fundamentally different mechanism than materials currently in use. In this view, Gd-doped CeO2 is representative of a new family of high-performance electromechanical materials.

 

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  • Prof. Igor Lubomirsky
1151
A method to significantly shorten acquisition times of high-quality MRI images. Multidimensional nuclear magnetic resonance (NMR) is used nowadays in many applications (e.g., discovery of new pharmaceutical drugs, characterization of new catalysts, and investigation of the structure and dynamics of...

A method to significantly shorten acquisition times of high-quality MRI images.

Multidimensional nuclear magnetic resonance (NMR) is used nowadays in many applications (e.g., discovery of new pharmaceutical drugs, characterization of new catalysts, and investigation of the structure and dynamics of proteins). One drawback of this technique is that, by contrast to one-dimensional spectroscpic methods, multidimensional NMR requires relatively long measurement times associated with hundreds or thousands of scans. This places certain kinds of rapidly-changing systems in Chemistry outside the scope of the technique. Long acquisition times also make this technique ill-suited for in vivo analyses and for clinical measurements in combination with magnetic resonance imaging (MRI). The current technology allows for the acquisition of multidimentional NMR scans using a single continuous scan, thereby shortening the time needed to acquire high-quality MRI images.

Applications


  • In vivo diagnostics

  • High-throughput proteomics/metabonomics

  • NMR of unstable chemical systems

  • Metabolic dynamics

  • High-resolution NMR in tabletop systems

  • Extensions to non-MR spectroscopies


Advantages


  • Can shorten the acquisition time of any multidimensional spectroscopy experiment by orders of magnitude
  • Compatible with the majority of multidimensional pulse sequences
  • Can be implemented using conventional NMR and MRI hardware

Technology's Essence


The outlined approach, called ultrafast multidimensional NMR, significantly expedites the analysis of the electromagnetic sounds produced, making it possible to acquire complete multidimensional NMR spectra within a fraction of a second. This technology “slices up” the molecular sample into numerous thin layers and then simultaneously performs all the measurements required on every one of these slices. The protocol then integrates these measurements according to their precise location, generating an image that amounts to a full multidimensional spectrum from the entire sample.

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  • Prof. Lucio Frydman

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