Caltech bioengineers develop 'microscope on a chip'July 29, 2008PASADENA, Calif.--Researchers at the California Institute of Technology have turned science fiction into reality with their development of a super-compact high-resolution microscope, small enough to fit on a finger tip. This "microscopic microscope" operates without lenses but has the magnifying power of a top-quality optical microscope, can be used in the field to analyze blood samples for malaria or check water supplies for giardia and other pathogens, and can be mass-produced for around $10. "The whole thing is truly compact--it could be put in a cell phone--and it can use just sunlight for illumination, which makes it very appealing for Third-World applications," says Changhuei Yang, assistant professor of electrical engineering and bioengineering at Caltech, who developed the device, dubbed an optofluidic microscope, along with his colleagues at Caltech. The new instrument combines traditional computer-chip technology with microfluidics--the channeling of fluid flow at incredibly small scales. An entire optofluidic microscope chip is about the size of a quarter, although the part of the device that images objects is only the size of Washington's nose on that quarter.
"Our research is motivated by the fact that microscopes have been around since the 16th century, and yet their basic design has undergone very little change and has proven prohibitively expensive to miniaturize. Our new design operates on a different principle and allows us to do away with lenses and bulky optical elements," says Yang. The fabrication of the microscopic chip is disarmingly simple. A layer of metal is coated onto a grid of charge-coupled device (CCD) sensor (the same sensors that are used in digital cameras). Then, a line of tiny holes, less than one-millionth of a meter in diameter, is punched into the metal, spaced five micrometers apart. Each hole corresponds to one pixel on the sensor array. A microfluidic channel, through which the liquid containing the sample to be analyzed will flow, is added on top of the metal and sensor array. The entire chip is illuminated from above; sunlight is sufficient. When the sample is added, it flows--either by the simple force of gravity or drawn by an electric charge--horizontally across the line of holes in the metal. As cells or small organisms cross over the holes, one hole after another, the objects block the passage of light from above onto the sensor below. This produces a series of images, consisting of light and shadow, akin to the output of a pinhole camera. Because the holes are slightly skewed, so that they create a diagonal line with respect to the direction of flow, the images overlap slightly. All of the images are then pieced together to create a surprisingly precise two-dimensional picture of the object. Yang is now in discussion with biotech companies to mass-produce the chip. The platform into which the chip is integrated can vary depending upon the needs of the user. For example, health workers in rural areas could carry cheap, compact models to test individuals for malaria, and disposable versions could be carried into the battlefield. "We could build hundreds or thousands of optofluidic microscopes onto a single chip, which would allow many organisms to be imaged and analyzed at once," says Xiquan Cui, the lead graduate student on the project. In the future, the microscope chips could be incorporated into devices that are implanted into the human body. "An implantable microscope analysis system can autonomously screen for and isolate rogue cancer cells in blood circulation, thus, providing important diagnostic information and helping arrest the spread of cancer," says Yang. California Institute of Technology | |||||||||||||||||||||
|
Related Microscope Current Events and Microscope News Articles Clemson researchers advance nano-scale electromechanical sensors Clemson physics professor Apparao Rao and his team are researching nano-scale cantilevers that have the potential to read and alert us to toxic chemicals or gases in the air. Put them into a small handheld device and the potential is there for real-time chemical alerts in battle, in industry, in health care and even at home. Montana State University researchers find gene that regulates mold's resistance to drugs Montana State University scientists concerned about lethal mold infections have found a gene that regulates the mold's resistance to drugs. Gold nanostar shape of the future Rods, cones, cubes and spheres - move aside. Tiny gold stars, smaller than a billionth of a meter, may hold the promise for new approaches to medical diagnoses or testing for environmental contaminants. Very cold ice films in laboratory reveal mysteries of universe The universe is full of water, mostly in the form of very cold ice films deposited on interstellar dust particles, but until recently little was known about the detailed small scale structure. Protein 'tubules' free avian flu virus from immune recognition A protein found in the virulent avian influenza virus strain called H5N1 forms tiny tubules in which it "hides" the pieces of double-stranded RNA formed during viral infection, which otherwise would prompt an antiviral immune response from infected cells, said Baylor College of Medicine researchers in an online report in the journal Nature. Type-1 diabetes not so much bad genes as good genes behaving badly, Stanford research shows Investigators combing the genome in the hope of finding genetic variants responsible for triggering early-onset diabetes may be looking in the wrong place, new research at the Stanford University School of Medicine suggests. Nanoscale dimensioning is fast, cheap with new NIST optical technique A novel technique under development at the National Institute of Standards and Technology (NIST) uses a relatively inexpensive optical microscope to quickly and cheaply analyze nanoscale dimensions with nanoscale measurement sensitivity. McMaster University unveils world's most advanced microscope The most advanced and powerful electron microscope on the planet-capable of unprecedented resolution-has been installed in the new Canadian Centre for Electron Microscopy at McMaster University. Engineering Nanoparticles for Maximum Strength Because they are riddled with defects, bulk crystalline materials never achieve their ideal strength; nanocrystals, on the other hand, are so small there's no room for defects. Digital zebrafish embryo provides the first complete developmental blueprint of a vertebrate Researchers at the European Molecular Biology Laboratory (EMBL) have generated a digital zebrafish embryo - the first complete developmental blueprint of a vertebrate. With a newly developed microscope scientists could for the first time track all cells for the first 24 hours in the life of a zebrafish. More Microscope Current Events and Microscope News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||