Scientists in the US and Israel have demonstrated an atomic force microscope that can take images of periodic processes with a time resolution of microseconds. This is an order of magnitude faster than is possible with conventional "rapid-scan" (M Anwar and I Rousso 2005 Appl. Phys. Lett 86 014101).

An atomic force microscope (AFM) works by measuring how the force between the sample and a tiny "tip" on a cantilever changes as the microscope is moved over the surface of the sample. This allows the AFM to record images with extremely high spatial resolutions. Previous attempts to increase the time resolution of AFMs have focused on scanning the tip over the sample as quickly as possible, but these techniques have had time resolutions of a few tens of milliseconds at best.

Higher temporal resolutions can be obtained by using the AFM in a "force-sensing" mode, which can detect movements from a single point on a sample. Moshiur Anwar of the Massachusetts Institute of Technology (MIT) and the University of California at San Francisco and Itay Rousso of MIT and the Weizmann Institute of Science have now developed a technique in which a series of individual force-sensing measurements are combined to construct images.

The new "step-scan" technique relies on breaking down a sample into individual pixels and then measuring the dynamics of each pixel separately with the AFM. The method, which only works for period processes, can resolve features 10 nanometres across with a time resolution of 5 microseconds.

Oak Ridge National Laboratory profile researchers, using a state-of-the-art microscope and new computerized imaging technology, have pushed back the barrier of how small we can see--to a record, atom-scale 0.6 angstrom. Researchers obtained the improved resolution with ORNL's 300-kilovolt Z-contrast scanning transmission electron microscope (STEM), aided by an emerging technology called aberration correction. The direct images have been acknowledged as proof of atom-scale resolution below one angstrom and provide researchers with a valuable tool for designing advanced materials.

"Looking down on a silicon crystal, we can see atoms that are only 0.78 angstroms apart, which is the first unequivocal proof that we're getting subangstrom resolution. The same image shows that we're getting resolution in the 0.6 angstrom range," said ORNL Condensed Matter Sciences Division researcher Stephen Pennycook.

To study tissues or small organisms with some microscopes, a developmental biologist has to be like a deli worker, slicing the sample as if it were luncheon meat to reveal the internal details.

But a microscope developed in Germany uses a slice of laser light to illuminate an intact specimen one thin layer at a time, eliminating the need to cut the sample. A lens and camera system takes images layer after layer, building a high-resolution picture of the entire specimen.

The instrument, called a selective plane illumination microscope and described in the current issue of the journal Science, promises to make the study of embryos and other living tissues much easier, say its developers at the European Molecular Biology Laboratory in Heidelberg. Samples can be kept alive and studied for hours or days while tissues develop and differentiate. The scientists say the microscope has better resolution than other living-sample imaging techniques, like multiphoton microscopy.

A team of researchers including University of California, Riverside Assistant Professor of Chemistry, Ludwig Bartels has developed a technique to take extremely fast snapshots of molecular and atomic movement. The development is considered a significant advance in surface science, the study of chemical reactions taking place on the surface of solids.

The results are reported in the current issue of the Journal Science and were also reported in the June 24 issue of Science Express... the online prerelease of the most important articles in Science.

The article, "Real-Space Observation of Molecular Motion Induced by Femtosecond Laser Pulses," details how carbon monoxide molecules move on a copper substrate when hit with extremely rapid laser pulses - a femtosecond is one millionth of a nanosecond - and tracks their movements.

prototype microscope that uses neutrons instead of light to “see” magnified images has been demonstrated at the National Institute of Standards and Technology (NIST). Neutron microscopes might eventually offer certain advantages over optical, X-ray and electron imaging techniques such as better contrast for biological samples.

Described in the July 19 issue of Applied Physics Letters,* the imaging process involves hitting a sample with an intense neutron beam. The neutrons that pass through—whose pattern reflects the sample’s internal structure—are directed into a row of 100 dimpled aluminum plates. Each dimpled plate acts like a weak focusing lens for neutrons, diverting the neutrons’ path slightly at each interface. The image then is projected onto a detector. Adelphi Technology Inc. of San Carlos, Calif., designed and demonstrated the microscope with the help of NIST scientists, who routinely use multiple lenses to focus neutron beams for other research.

An array of magnetic traps designed for manipulating individual biomolecules and measuring the ultrasmall forces that affect their behavior has been demonstrated by scientists at the National Institute of Standards and Technology (NIST).

Described in a recent issue of Applied Physics Letters, the chip-scale, microfluidic device works in conjunction with a magnetic force microscope. It's intended to serve as magnetic "tweezers" that can stretch, twist and uncoil individual biomolecules such as strands of DNA.

MRI with 80-nm resolution, far better than for the best medical scans, has been achieved with a device that combines atomic force microscope (AFM) and nuclear magnetic resonance (NMR; also known as magnetic resonance imaging, or MRI) technology.

In the hybrid methodology called magnetic resonance force microscopy (MRFM), a tiny magnetized particle is attached to a cantilever which is then brought near a sample which surrounded by a coil that emits radio waves. When a tiny magnetic domain in the sample feels just the right amount of magnetic field from the nearby coil and magnetic particle it will vigorously interact with them resonantly. (The tiny volume being probed is referred to as a voxel, and the sample-coil-particle combination is equivalent to the setup in a standard MRI machine for imaging, say, a tumor.)

Scientists in the US claim to have found a new way to image tiny structures and molecules, such as DNA, which are smaller than the 200 nm diffraction-limited resolution of optical microscopes.

Dehong Hu and Peter Lu from the Pacific Northwest National Laboratory (PNNL) in Washington State, revealed their technique to delegates at the American Chemical Society's national meeting which took place in Anaheim, California last week.

The duo have successfully combined fluorescence lifetime imaging microscopy (FLIM) with atomic force microscopy (AFM) to generate sharp images of fluorescing nanobeads which are just 40 nm in diameter, as well as a cluster of DNA molecules.

Researchers from BioForce Nanosciences Inc., Iowa State University, and Des Moines University have combined an atomic force microscope with a method of capturing virus particles to produce a tool that rapidly detects viruses.

The atomic force microscopy immunocapture assay consists of a chip, dubbed the ViriChip, that contains antibody molecules used to selectively capture viruses. An atomic force microscope is then used to analyze what has been trapped. Atomic force microscopes use nanoscale tips to trace the topography of surfaces and are capable of detecting individual atoms.

German-Austrian research team presents a method of measuring time in the region of a few hundred attoseconds, allowing the observation of atomic processes on this time scale

The electromagnetic field of visible light changes direction approximately one thousand trillion times per second, so that the intensity of the light field varies from zero to maximum faster than a femtosecond (1 femtosecond being one thousandth of a trillionth of a second). By precisely controlling these hyperfast oscillations in a short laser pulse scientists from the Vienna University of Technology and Max Planck Institute for Quantum Optics in conjunction with their colleagues from the University of Bielefeld succeeded in developing the first measuring apparatus: An "ultrafast stopwatch". This apparatus is capable of measuring the duration of atomic processes with an accuracy of less than 100 attoseconds (1 attosecond being one tousandth of a femtosecond). A 250?attosecond X-ray pulse initiates the atomic process to be measured and the attosecond stopwatch at the same time. This new measuring method now allows for the first time observation of ultrafast processes in the electron shell of atoms.

With the most modern microscopes scientists can observe atoms at rest. If, however, the atoms are in motion, very short light pulses are needed to reconstruct the motion from a series of snapshots. Whereas an exposure time of less than a thousandth of a second is sufficient for sharp imaging of a tennis-ball in flight, the light pulses have to be shortened by a billionth, to just a few femtoseconds, in order to record the fastest atomic motions in molecules. Inside the electron shell of excited atoms electrons fly a thousand times faster. They change from one energy state to another typically within 10 to a few 1000 attoseconds and in the process cause atoms originally bound in a molecule to fly apart or emit ultraviolet radiation or X-rays. These processes are of fundamental significance for controlling chemical reactions and synthesising new materials. They could even be applied for designing a versatile X-ray laser.

By modifying the surface of tiny, fluorescent crystals called quantum dots, Carnegie Mellon University scientists have enabled them to circulate for hours in animals and to provide fluorescent signals for at least eight months, the longest that anyone has observed quantum dot fluorescence in a living animal. This technological feat overcomes a major limitation, making quantum dots finally practical for long-term studies in mammals.

Medical ultrasound equipment tends to be bulky. But tiny devices micromachined from silicon may one day slim the technology down so much that crucial parts could be placed inside the body. Then doctors might be able to gather images of artery-harming plaque, for instance, from inside the arteries themselves.

A Stanford University scientist, Butrus T. Khuri-Yakub, has developed a prototype of a highly miniaturized ultrasound device. Dr. Khuri-Yakub, a professor of electrical engineering, said that arrays of the devices, a type of transducer fabricated using standard semiconductor technology, might one day appear in many medical applications, from portable prenatal screeners to hand-held scanners used on battlefields to check the injured for internal bleeding.

Physicists have observed movements on subatomic scales in a crystal for the first time by watching magnetic domain walls move by as little as half an angstrom (10-10 m). This is 100 times better than the best spatial resolution achieved in previous experiments (K S Novoselov et al. 2003 Nature 426 812

QuantomiX announced a new product that allows electron microscopy of biological and other wet samples in almost any electron microscope. It features a membrane that is relatively transparent to electrons but impermeable to water. Information on the composition of the membrane is not provided, but they refer to "nanotechnology" in its production.

Chemists at the University of Toronto have captured atom-scale images of the melting process-revealing the first images of the transition of a solid into a liquid at the timescale of femtoseconds, or millionths of a billionth of a second.
The result is an unprecedented "movie" detailing the melting process as solid aluminum becomes a liquid.