Posts Tagged ‘optics’
Make a High-Res 3-D Image of Just About Anything Anywhere, Using MIT’s New Gel
Described simply (you can get the more in-depth description via the video below), the system’s key component is a piece of transparent, synthetic rubber coated on one side with a metallic paint composed of very tiny particles. When the non-painted side is pressed against an object--even an object with very small features like the ink on a piece of paper (see image above)--the metallic paint deforms to capture those features.
Cameras set at various angles then capture that deformation from all sides, and computer-vision algorithms turn them into 3-D images. Contrast that with the usual method of obtaining a 3-D image with similar resolution--expensive and sensitive microscopes, vibration isolation tables, high-powered computers--and GelSight, as it is known, looks like a pretty big leap forward for both resolution and sheer simplicity.
GelSight also gets around a key problem with 3-D imaging. By translating an object’s most minuscule features--GelSight can measure features down to less than one micrometer in depth and roughly two micrometers across--through the gel to the metallic paint, it circumvents imaging problems introduced by the various optical properties of various materials (like, for instance, an opaque gel or a clear crystalline object, both of which interact with light differently than, say, a solid object that lets no light pass through).
Potential applications range from distinguishing moles from cancerous growths to quickly and cheaply inspecting manufactured goods to matching spent bullet casings to the firearms that fired them. See GelSight in action below.
[]
Advanced Optics That Let Telescopes See Deep Into Space Will Help Microscopes See Deep Inside Cells
In astronomy, adaptive optics fixes the blurring of deep-space images by correcting for the turbulence in Earth’s atmosphere. These techniques have allowed the Keck telescopes in Hawaii to resolve deep-space objects with greater clarity than the Hubble Space Telescope. In microscopy, blurring is caused by the flowing cytoplasm of living cells, and adaptive optics can be used to correct for that, too.
Electrical engineers at the new W. M. Keck Center for Adaptive Optical Microscopy at UC Santa Cruz will develop new adaptive optics systems that can peer inside stem cells, for instance, to see how they differentiate.
Recent advances in optical microscopes have allowed scientists to and to in real time, both major improvements that increase resolution without harming living cells. But even the best microscope images are only clear up to the surface of the cells, according to William Sullivan, a UCSC cell biology professor. When peering inside the cell, things start to get blurry.
Adaptive optical microscopy would work by establishing a biological “guide star” as a reference point, and correcting for the distortions caused by cytoplasm flow.
In astronomy, telescopes use a star or a laser as a control beacon by which atmospheric blurring can be measured. The Keck Observatory shines a laser to create a fake “guide star” about 60 miles up — above most of the atmosphere — and uses it to measure starlight distortions. The light is bounced off a deformable mirror that smooths out the image. This process repeats every millisecond.
The UC Santa Cruz project is developing genetically engineered fluorescent proteins to serve as guide stars. The ideal protein would be small and it would look like a dot, providing a point source of light, a UC Santa Cruz explains. Sullivan is working with fly embryos and using a protein that tags a the center of a chromosome as the guide star. The rest of the chromosome is tagged with a different color.
Eventually, the researchers hope to develop a suite of guide star proteins that would help illuminate any kind of tissue.
“This has the potential to open up vast areas of cell biology that have been opaque to us,” Sullivan said.
House Subcommittee’s Budget Bill Puts Most Powerful Space Telescope on the Chopping Block
To be clear, there are many more steps in the budget process before this is final — lawmakers are working on next year’s budget despite a stalemate between the White House and Republican leadership, so a lot could change in the next couple weeks. And odds are decent that at least some lawmakers will fight to preserve this enormous technological marvel (and the jobs associated with its construction). But this is not good news for astronomy, to put it mildly.
The House Appropriations Committee released its funding bill today, ahead of a scheduled committee markup Thursday. The bill provides $50.2 billion overall for the nation’s projects in those three areas, which is $7.4 billion less than President Obama’s budget request. NASA’s budget is slashed by $1.6 billion, which is $1.9 billion less than Obama wanted. About $1 billion of that comes from the end of the shuttle program, and NASA Science funding is cut by $431 million from last year.
“The bill also terminates funding for the James Webb Space Telescope, which is billions of dollars over budget and plagued by poor management,” an Appropriations Committee says flatly.
While management problems are a little more subjective, the telescope is indeed massively over budget, as we’ve . In November, a congressional panel described the telescope as “NASA’s Hurricane Katrina,” because of its destructive toll on other agency projects. That review found the telescope’s price tag had mushroomed to $6.5 billion and that it would not be ready until at least 2015. Then, just last week, the watchdog site obtained a memo from Goddard Space Flight Center describing that it may not launch until after 2018 — even that is “unfeasible,” the report said.
But that earlier report, last November, also pointed out a key fact: “The funds invested to date have not been wasted.” The JWST has enabled several engineering feats, from compounds to a huge space umbrella that will shield it from the sun. The umbrella will unfurl in space along with an enormous 18-piece primary mirror made of material that is supposed to warp in frigid temperatures. Astronomers say the JWST will provide unprecedented imagery of the deepest corners of the cosmos.
This bombshell is not the only piece of bad news for the scientific community. The National Science Foundation is also losing funding, set to receive $907 million less than Obama requested as part of his campaign to The NSF will get a modest $43 million for core research, . Aside from that, NOAA is down $1 billion. The Environmental Protection Agency is down $1.5 billion, about 18 percent.
Pentagon spending would grow by $17 billion in 2012, on the other hand.
Again, this is all far from over, and plenty of fiscal feuding remains before we can write the JWST’s obituary. But with a budget debate raging in Washington — and, many economists say, the specter of a new economic crisis looming — future space telescopes could be a low priority.
[via ]
World’s Most Powerful Laser Gets Government Go-Ahead
The Extreme Light Infrastructure will be built in Eastern Europe
The lasers will be the first to operate in the exawatt scale--a quintillion watts. That’s about a million times more powerful than 10 billion 100-watt lightbulbs. And a fourth superlaser should be forthcoming, one with beams twice the power of these three. This is the laser that was theorized to be the .
The list of implications for this never-before-seen technology is long, reaching into cancer diagnosis and treatment, elimination of nuclear waste, broadening of the technology industry, and expansion of nanoscience and molecular chemistry research.
Several countries competed for the honor of hosting the laser. ELI's most important research laser will find its home in the Czech Republic while the other two will reside in Hungary and Romania.
[ via ]
Coming Soon: Disposable Endoscopes Featuring the World’s Tiniest Cameras
Endoscopy involves inserting a cable with a camera lens on it through your body’s natural openings or through small incisions, so doctors can check out internal organs, examine injuries or perform surgery. But endoscopes are complex to produce, requiring complex silicon wafer etching, which means they’re expensive. They also must be carefully sanitized with each use, which is time-consuming.
The new model, designed at the Fraunhofer Institute for Reliability and Microintegration in Berlin, is so cheap that it could be tossed out with the doctor’s latex gloves.
It’s possible with a new fabrication method that simplifies the wiring of the image sensors, according to a . Typical endoscopic cameras consist of a lens at one end and a sensor at the other, but this one is self-contained, as . The camera has a resolution of 62,500 pixels and transmits images through an electrical cable.
It’s just one cubic millimeter in size, which the researchers say is the smallest camera known.
Along with medical applications, endoscopes are used in bomb disposal and in the construction industry. The automotive industry is apparently interested in this new one, according to Fraunhofer — the tiny cameras could be used to replace outside rear-view mirrors, improving cars’ aerodynamics, or they could be installed to monitor drivers’ eye movements to make sure they’re paying attention to the road.
The German image sensor firm Awaiba GmbH developed the tiny endoscope with Fraunhofer Labs, and its owner hopes to commercialize the technology by next year.
[ via ]
Video: New Microscope Produces 3-D Movies of Live Cells In Action
Cell biologists get observational omniscience
The technique uses a highly focused, super-thin beam of light similar to the type used in supermarket checkout scanners. It could allow cell biologists to watch the molecular underpinnings of cell action as they unfold.
“In looking at living systems, you want to be God. You want to have this omniscient power and be able to look at all time scales — not just single cells sitting on a microscope cover slip, but observe what’s happening in a single molecule in a single cell that is inside your heart right now. That’s the dream,” said Eric Betzig, research leader at the Janelia Farm Research Campus, part of the Howard Hughes Medical Institute. “You want to have this (omniscience) in a way that the organism is completely unaware and unaffected by that observation.”
The new technique, called Bessel beam plane illumination microscopy, could be the best way to do that without harming the cells.
In the past few months, other microscopy advances have allowed scientists to see 3-D structures of cells for the first time. MIT researchers are with magnetic resonance imaging to unveil 3-D images, for instance. A under development at the University of Massachusetts uses a fluorescent tagging technique (which Betzig has also studied) to create mosaic images. And just this week, scientists in the UK announced a new technique that amplifies optical observations to see , allowing cell and virus observations.
These are all promising techniques, but they’re equivalent to taking a snapshot. When you are trying to understand complex processes, a snapshot is only worth so much — ideally, you would capture a live-action movie. It’s more useful to watch the process of chromosomes pulling apart during cell division, like in the following video, or to see the ruffling of cell membranes, seen further below.
A movie would require observing a cell for a long time, but that causes some problems. If cells are not killed for the purposes of observing them, the process of lengthy observation does them in. One commonly used technique, confocal microscopy, uses a pinhole method to block out-of-focus light, allowing observations of very precise regions in the microscope’s focal plane. But the whole specimen is still blasted with light, Betzig said.
“You can’t study cells for too long before they literally curl up and die,” he said. “And you can’t study them very fast, because you have to scan them with a little point of light.” The images are distorted, too, he said.
Betzig was looking for ways to overcome these problems, and started studying plane illumination, or shining light at a subject from the side rather than from below, like most microscopes. A European group developed a plane illumination microscope in 2003, and used it to show the development of an embryo as cells continually divided.
“They work very well when you are looking at embryos, which are hundreds of micrometers in diameter,” Betzig said. “But they’re not so great if you want to peer inside the guts of what is happening in each cell, which is what I wanted to do.”
His research group decided to use a special focused beam called a Bessel beam, which does not diffract over long distances the way that regular light beams do. To keep the light super-focused, they had to modulate the beam, turning it on and off as it sweeps across the sample. The result is a series of high-speed images, which can be put together into a movie.
“We can study cells in their 3-D complexity at very high speeds for long periods of time. It’s the combination of high axial resolution, plus high speed, plus the non-invasiveness that makes it special,” Betzig said.
The wriggling mitochondria in this video represents 300 image stacks, each containing 300 two-dimensional images, taken in one second.
“That’s almost 100,000 images of a cell, without bleaching it or harming it,” Betzig said. “In in a second, can create an entire 3-D picture of what went on in that cell in that last second.”
The next step could be combining the Bessel beam plane technique with super-resolution techniques, Betzig said. That would be something — with no limits on how small we can see, and an imaging technique that take movies without harming organisms, the possibilities seem endless.
World’s Most Powerful Optical Microscope Lets Researchers See Inside Viruses
New technology breaks the theoretical limit on how small we can see
With the new method, there is theoretically no limit on how small an object researchers will be able to see. It could potentially see inside human cells and examine live viruses for the first time.
The standard optical microscope can only see items down to about one micrometer. To see things in the nanoscale, researchers use methods like scanning tunneling microscopes, scanning electron microscopes, transmission electron microscopy and atomic force microscopy.
But these techniques are limited in scope, especially for applications like medicine. Electron microscopes can only see the surface of a cell, rather than examining its structure, for instance. And there is no way to see a live virus in action.
The new method works by integrating a microsphere “superlens” with a traditional optical microscope. The spheres magnify images of items that are placed on the microscope plate, touching the microsphere and forming “virtual images,” according to authors Zengbo Wang, Wei Guo and Lin Li of the University of Manchester, UK. The optical microscope magnifies the virtual images, forming a greatly enhanced image.
“The microspheres are in contact with objects, and the microscope must focus below the object surface to capture the image. This is a very different practice from the normal use of microscopes,” Li said in an e-mail.
Optical diffraction limits dictate that the smallest object that can be seen is around half the optical wavelength. For visible light, this is about 200 nanometers to 700 nanometers. That means the smallest thing you can actually see is about 200 nanometers — pretty small, but not small enough to resolve interesting molecules and cells.
The new method allowed Li and colleagues to see objects at 50 nanometers, he said.
“This clearly breaks the theoretical optical imaging limit,” he said.
It also overcomes some drawbacks associated with electron microscopes. A TEM sends a beam of electrons through an object, interacting with it as they pass through it. The device forms an image of this interaction and magnifies it. An SEM scans an object with a high-energy electron beam, which also interacts with the sample. The interaction can provide information about the object’s topography and composition. An STM applies a voltage very close to an object, allowing electrons to tunnel through the space between them. This current can be monitored as the voltage tip moves across the object, and is translated into an image. And an AFM essentially feels a surface using a mechanical probe.
Optical fluorescence microscopes can see inside cells by dyeing them, but it can’t penetrate viruses, and it would be nice to see cells without having to inject them with dye. What’s more, the electron methods involve chemical reactions that must be accounted for. Last year, for instance, IBM researchers made an AFM to figure out its chemical composition, but some scientists wondered whether the measuring method itself interfered with the molecule’s structure. It required putting the molecule on a salt crystal, but if no one knew the shape to begin with, they can’t know whether the salt affects the shape.
So it would be nice if you could just take a look at something and see it for yourself. This new method will allow that to happen — imaging viruses, DNA and molecules in real time.
The method uses optical near-field images, which has no diffraction limit, Li said. Near-field images are within the optical wavelength of the optics involved. Far field is beyond that distance.
“Therefore, theoretically, there is no limit on how small we can see. It will depend on how much can we amplify the image using the spheres and relay it to the far field,” Li said.
The team's paper is published in the journal Nature Communications.