Manufacturing Bits: Nov. 28

Cryogenic microscopes
The European Synchrotron Radiation Facility (ESRF) has developed and commissioned a new cryo-electron microscope.

A form of transmission electron microscopy (TEM), cryo-electron microscopy (cryo-EM) is used to study a sample at cryogenic temperatures. A gas is assumed to be cryogenic if it can be liquefied at or below −150 °C.

Cyro-EM is often used in structural biology. In one application, a cryo-EM is used to freeze biomolecules mid-movement. Then, the structure is imaged at atomic resolutions. The system allows researchers to produce films that reveal how molecules interact with each other.

The TITAN KRIOS cryo-electron microscope (Source: ESRF)

“One of the greatest advantages of cryo-EM relative to conventional structural biology techniques is its ability to analyze large, complex and flexible structures,” according to FEI, part of Thermo Fisher Scientific. “Often times these cannot be crystallized for X-ray crystallography (XRD) or are too large and complex for nuclear magnetic resonance (NMR) spectroscopy. These include many biologically important proteins, especially those with variable or flexible structures like membrane proteins. The established methods for structure determination, XRD and NMR, are now routinely integrated with cryo-EM density maps to achieve atomic-resolution models of complex, dynamic molecular assemblies.”

Christoph Muller-Dieckmann, a researcher from Grenoble, France-based ESRF, said: “The ESRF international scientific community can now use the information obtained both from diffraction experiments and from cryo-EM in a complementary fashion to better and more fully interpret action and function of complex bio-macromolecules. It will allow scientists to push the field of structural biology forward, to better understand the nature of health diseases, and to develop new drugs.”

Droplet microscopy
Seeking to improve the ability to characterize hydrophobic surfaces, Finland’s Aalto University has developed a new measurement technique called scanning droplet adhesion microscopy (SDAM).

SDAM is used to characterize the wetting properties of super-hydrophobic materials. Wetting is a phenomenon, which represents how well liquid spreads on a surface. At times, for example, water can come into contact with a water-repellent surface. Then, the droplets bead up and roll off the surface. This is an example of a hydrophobic surface.

Researchers hope to gain a better understanding of the properties of hydrophobic or super-hydrophobic surfaces at the nanoscale.

The problem? It is challenging to quantify and map the microscopic variations of wettability on surfaces. Existing contact angle and force-based methods lack sensitivity and resolution, according to Aalto University.

In comparison, SDAM is 1,000 times more precise than the current wetting characterization methods. It also has the ability to measure features with microscale resolution. “Our novel microscope will promote the understanding of how wetting emerges from surface microstructures. The measuring instrument can also detect microscopic defects of the surface, which could allow coating manufacturers to control the quality of materials. Defects in self-cleaning, anti-icing, anti-fogging, anti-corrosion or anti-biofouling products can impeach the functional integrity of the whole surface,” said Robin Ras, a professor from Aalto University.

The droplet probe of the microscope on a superhydrophobic golden birdwing (Troides aeacus) butterfly wing. (Photo: Matti Hokkanen / Aalto University)

Middle East research center
The Middle East’s first major international research center has achieved a major milestone.

The research center, dubbed SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East), has begun conducting research in its new synchrotron light source facility.

In the works since 2004, SESAME was officially opened in May. Based in Allan, Jordan, SESAME’s members are Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, the Palestinian Authority, and Turkey. The users of SESAME will be scientists and students in the Middle East and neighboring countries.

The SESAME synchrotron is currently operating with a beam current of just over 80 milliamps. Eventually, the system will be scaled up to 400 milliamps. Synchrotron light sources are circular or storage ring structures. They are designed to accelerate charged particles, which in turn emits light. Synchrotron light sources are used for various measurement techniques, such as X-ray diffraction and scattering.

Recently, researchers from the SESAME facility saw the first monochromatic light through an XAFS/XRF (X-ray absorption fine structure/X-ray fluorescence) spectroscopy beamline, signaling the start of the laboratory’s experimental program.

The XAFS/XRF beamline delivers X-ray light, which will be used to carry out research in areas, such as solid state physics, environmental science and archaeology. Another beamline, based infrared (IR) spectromicroscopy, will come online later. “SESAME is a major scientific and technological addition to research and education in the Middle East and beyond,” said Director General of SESAME, Khaled Toukan. “Jordan supported the project financially and politically since its inception in 2004 for the benefit of science and peace in the region. The young scientists, physicists, engineers and administrators who have built SESAME, come for the first time from this part of the world.”