Posts Tagged ‘imaging’
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.
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Students’ Innovative 3-D Vision System Wins Prize
PopSci and National Instruments hand top honors to a Chinese team that could revolutionize 3-D
College students have a special aptitude for bending LabView to their will, and the finalists on display in Austin were very hard to choose between.
Rice University built a sensor-filled baseball that precisely transmits the mechanics of a throw to better teach pitching. UC San Diego created a trumpet that not only detects the exact pitch being played, but can bend that pitch in real time to hit the proper note—a sort of auto-tune for the brass section. The University of Konkuk, South Korea, created an autonomous flying drone out of remarkably few parts. And the University of Leeds built an astounding haptic feedback system for simulating the feel of tumors under the hands of doctors in training.
In the end, however, we chose the entry from Tsinghua University, China. Five students there built an entirely new 3-D imaging system. They conquered the classic glasses-or-no-glasses problem by simply stepping around it: instead of a conventional flat screen, they built a four-sided glass enclosure which displays the four sides of a simulated object. The system scans an object on a turntable, acquires the image data, and reproduces it by projecting the image with four projectors onto four panes of glass. Walk around the simulated object on display, and it’s like walking around it in real life. In addition, the system recognizes gestures, allowing you to rotate and zoom in on an object with your hands. You can imagine the implications for medical analysis, enhanced teaching, point-of-sale displays, and telecommunication.
The thing that blew my mind, however, was the sheer discipline of these kids in dealing with costs. They had developed several alternative systems, they told me, including one that used a rotating mirror and a high-speed projector. But they had given themselves the goal of keeping the thing cheap, and this was the cheapest workable solution.
The adoption of prototying software like LabView seems to be collapsing the time and costs involved in building new devices. “We’re still far away from a product,” Gao Yongfeng, a member of the 3-D team, told me. But the kid’s still in college. By the time he’s headed to grad school, this thing could be on store shelves.
Quantum Dots Can Tag Individual Molecules With A Fluorescent Glow
With their bright, continuous fluorescent glow that transitions between red, green and yellow, the nanoparticle is a better way to tag molecules, both in its function and in its good looks.
Earlier attempts to tag molecules with bright quantum dots were hindered by the dots' on-and-off blinking, like trying to follow a blinking flashlight through a dark room. The Ohio State engineers fixed the faulty flashlight. Led by assistant professor Jessica Winter and research scientist Gang Ruan, the team placed a group of quantum dots inside a slightly larger plastic nanoparticle. Whenever a single quantum dot within the nanoparticle blinked off, the team simply followed the glow of its neighbors.
The team used green and red quantum dots. Nanoparticles filled with red dots glow red, while those with green dots glow green. The almost magical color changes occur in the nanoparticles containing a mix of red dots and green dots. When a green dot blinks at the same time as a red dot neighbor, the light appears yellow to the eye. The quantum dot flashes mix together to become blobs of color that melt away as other colored blobs materialize, making the nanoparticle look like a miniature lava lamp.
Using the new technology, which the Ohio State research team is trying to patent, scientists could gain a better glimpse of biological processes at a cellular level.
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Quantum Dots Can Tag Individual Molecules With A Fluorescent Glow
With their bright, continuous fluorescent glow that transitions between red, green and yellow, the nanoparticle is a better way to tag molecules, both in its function and in its good looks.
Earlier attempts to tag molecules with bright quantum dots were hindered by the dots' on-and-off blinking, like trying to follow a blinking flashlight through a dark room. The Ohio State engineers fixed the faulty flashlight. Led by assistant professor Jessica Winter and research scientist Gang Ruan, the team placed a group of quantum dots inside a slightly larger plastic nanoparticle. Whenever a single quantum dot within the nanoparticle blinked off, the team simply followed the glow of its neighbors.
The team used green and red quantum dots. Nanoparticles filled with red dots glow red, while those with green dots glow green. The almost magical color changes occur in the nanoparticles containing a mix of red dots and green dots. When a green dot blinks at the same time as a red dot neighbor, the light appears yellow to the eye. The quantum dot flashes mix together to become blobs of color that melt away as other colored blobs materialize, making the nanoparticle look like a miniature lava lamp.
Using the new technology, which the Ohio State research team is trying to patent, scientists could gain a better glimpse of biological processes at a cellular level.
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Visible-Light Lens Can See Objects Tinier Than The Light’s Wavelength
So how do you cross that wavelength limit and image something smaller than the wavelength of the light itself? Their new lens is basically a frosted piece of glass--a transparent slab that’s etched on one side to scatter the light going through. Picture it with the etched side facing the light source; the light hits the etching and scatters, bending the wave front and producing distorted light from the other side.
The Dutch team (they’re from the University of Twente) measures this light distortion using a CCD chip, which gives them a reading of the distorted light’s shape. Using that data, they then send the light through the lens again, but this time they run it through a modulator that lets them distort the light to their liking. In this way they can actually inject light through the lens that’s already distorted in such a way that it cancels out the lens distortion.
But that’s not the trick. The real trick is tweaking the light just right so that it comes into a focal point that is much tighter than what can be achieved using a regular lens relying on only refraction to focus the light. The team’s setup is so spot-on accurate that they can actually move the focal point around, allowing them to scan back and forth over a nanoscale object and build an image.
Ninety-seven nanometers sets a new record for microscopy with visible light, but the team says with a bit more work they can get the resolution down to 72 nanometers. That more than doubles the resolution of conventional lenses, and could make microscopy in the visible range capable of resolving things like nanoelectric circuits or organelles that were previously too small to image with visible-light tools.
For the entire paper on the imaging method, check out .
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Single Stationary Microscope Lens Can Capture 3D Images
Postdoctoral researcher Lei Li wrote a computer program to create the lens; then he and Ohio State associate professor Allen Yi cut the lens from acrylic glass, a type of transparent plastic, with a diamond blade. The finished product is shaped like a rhinestone, with a flat top and eight surrounding facets. Unlike a gem cut for jewelry, though, these facets are not symmetrical. Each one captures images from a different angle. The images from each facet are then combined on a computer to form the 3-D image.
The engineers have successfully used the lens to create 3-D images of a ballpoint pen tip, measuring about one millimeter across, and a tiny drill bit that has a diameter of 0.2 millimeters. The technology is intended to help simplify the currently complex machinery manufacturers use to produce tiny components. While the prototype lens was created with a precision cutting machine, the researchers say it could be produced less expensively with more traditional molding.
Using X-Ray Laser, Researchers Image a Single Virus, Destroying It In The Process
To achieve this, a team of scientists injected a stream of buffer and viruses into the path of the X-ray beam, which was pulsing with a 10-micron-diameter beam. From the resulting diffraction pattern of the photons collected, they were able to accurately rebuild the capsid of the virus.
The rebuilding of the virus isn’t what’s particularly noteworthy here. Rather, its the fact that the researchers were able to identify and collect a sufficient diffraction signal from a single exposure of a single particle even as the X-ray beam is destroying it. Higher energy X-rays and shorter pulses should increase the resolution, and researchers are working on that now.
Coupled with a second study in which researchers were able to image the nanocrystals in proteins via a similar femtosecond X-ray method (both papers were published in the journal Nature), it seems this kind of imaging is on the fast track toward resolutions that can image the structures of single molecules.
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