Manufacturing Bits: Oct. 8

X-ray vision; imaging through wafers; neutron scopes.


X-Ray Vision
Researchers led by the University of Manchester have developed a new type of X-ray vision. The technology can look inside objects and map the properties in 3D and in real time.

This technology is called pair distribution function-computed tomography. Applications include materials science, biomaterials, geology, environmental science and palaeontology.

The technology enables nanocrystalline and amorphous structures to be identified, quantified and mapped, according to researchers, who have demonstrated this method with a phantom object. The technology resolved the physicochemical states of a heterogeneous catalyst system, according to researchers.

“When X-rays hit an object they are either transmitted, absorbed or scattered,” said Robert Cernik, a professor in Manchester’s School of Materials, on the university’s Web site.


“Standard X-ray tomography works by collecting the transmitted beams, rotating the sample and mathematically reconstructing a 3D image of the object. This is only a density contrast image, but by a similar method using the scattered X-rays instead we can obtain information about the structure and chemistry of the object even if it has a nanocrystalline structure,” he said. “By using this method we are able to build a much more detailed image of the object and, for the first time, separate the nanostructure signals from the different parts of a working device to see what the atoms are doing in each location, without dismantling the object.”

The international research team also included scientists from the University College London, the European Synchrotron Radiation Facility, Grenoble, the U.S. Department of Energy’s Brookhaven National Laboratory and Columbia University.

Imaging Through Wafers
The Massachusetts Institute of Technology (MIT) and the University of Texas at Arlington (UTA) have devised a microscopy technology that can image cells through a silicon wafer.

The technology is able to measure the size and mechanical behavior of cells behind a wafer. One of the main applications is microfluidics. Microfluidics deals with the control of fluids in devices. Tiny chip-like devices using microfluidics are used in many applications, such as cell sorting and detection, gene analysis, inkjet print heads, lab-on-a-chip units and point-of-care diagnostic tools.

Using quantitative phase imaging, MIT and UTA researchers created this image of red blood cells.  Source: MIT

Using quantitative phase imaging, MIT and UTA researchers created this image of red blood cells. Source: MIT

Researchers from MIT and UTA have devised a technique for label-free, rapid visualization of a structure using traditional opaque media. The technique combines the principles of near-infrared (NIR) spectroscopy and quantitative phase imaging.

Quantitative phase imaging sends a laser beam through a sample. Then, the beam is split into two. The two beams are recombined and information is compared. In doing so, the height and a refractive index can be determined in a sample.

Traditional quantitative phase imaging uses a helium neon laser. In contrast, researchers from MIT and UTA used a titanium sapphire laser, which can be used for infrared and near-infrared wavelengths at 980nm.

With the technology, researchers demonstrated full-field imaging of erythrocyte morphology. They also observed variations of human embryonic kidney cells, through a silicon substrate, in response to hypotonic stimulation. “This has the potential to merge research in cellular visualization with all the exciting things you can do on a silicon wafer,” said Ishan Barman, a former post-doctoral student in MIT’s Laser Biomedical Research Center (LBRC), on the university’s Web site.

Neutron Scopes
The Massachusetts Institute of Technology and NASA have developed a microscope using neutrons to create high-resolution images.

The technology, called small-angle neutron scattering (SANS), was conceived some 40 years ago. Today’s SANS technology mainly consists of instruments with pinhole cameras. These imaging systems let light through a small opening.

Researchers from MIT and NASA have developed a new concept. They built a small prototype SANS instrument using axisymmetric focusing mirrors. By using a detector with 48-μm pixels, researcher devised what they claimed is the world’s most compact SANS instrument.

The instrument could increase the signal rate by at least fiftyfold for large samples at high resolutions. A neutron-based microscope could be used to probe inside metal objects, such as fuel cells, batteries, and engines. Neutron scopes are also sensitive to magnetic properties. “We are turning the field of neutron imaging from the era of pinhole cameras to an era of genuine optics,” said David Moncton, a professor at MIT, on the university’s Web site.