A Mini Microscope Within Your Reach
Posted on July 30, 2008 in Current Affairs by Danteshwari
Researchers at California Institute of Technology have developed a miniaturized microscope, which is small and can be be placed on the tips of the fingers, but has a high magnifying power.
The “microscopic microscope” functions without any lenses. It can be utilized for analyzing malaria blood samples as well as to keep a tab on water supplies meant for pathogens and Giardia.
The microscope can be placed in a cell phone, and for illumination it can make use of sunlight, which is very appealing to the Third World countries, according to Changhuei Yang , California Institute of Technology (Caltech). He is a team member responsible for the developing of the device, which is dubbed as optofluidic microscope.
The new device can be produced on a mass level and will cost only $10. It will combine micro-fluidics (fluid flow is channelized at very small scales) with the computer-chip technology that is traditional.
The optofluidic microscope is similar to the size of a coin, although the portion of the device meant to image the objects is only a tiny fraction of it. Yang says that that the purpose to come up with such a microscope was to get rid of bulky objects as well as lenses.
How is the microscope made?
The method is simple and easy. Layer of metal is applied on a grid of charge-coupled device (CCD) sensors ( made use of in digital camera). Next, a row of very small holes (less than one-millionth of a meter in diameter) is punched into the metal, which are five micrometers apart. Each hole is similar to one pixel located on the sensor array.
The liquid , which contains the sample to be analyzed will flow through a microfluidic channel and is placed above the sensory array and metal. The complete chip will be illuminated from top; sunlight is enough for it. On the sample being added, it flows- due to gravitational force or with the help of an electric charge- horizontally across holes located in the metal.
As the small organisms or cells pass over the holes, one after the other. The objects block the light from top onto the sensor below. Then a series of images is produced, which consists of shadow and light, which is similar to the pinhole of a camera.
As the holes are a bit skewed, in order for the diagonal line to be created keeping to the flow direction. The images get overlapped slightly. Then, the images are put together to create an exact two-dimensional image of the object.
Source :TOI July 30th,2008
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