Droplet optics: This series of pictures shows droplets of water in a hollow Teflon cylinder every four milliseconds. The curved shape of the water forms a lens, which changes shape, and therefore focal length, when sound waves are applied to one side of the cylinder.
Amir Hirsa
An adjustable-focus lens made of two drops of water could be used in small cameras.
Lenses made of liquid have interested researchers and engineers for decades because of the technology's ability to quickly change shape and focal length. But traditional approaches, which use an electric current to change the surface shape of a liquid, require a lot of power. Now, researchers at Rensselaer Polytechnic Institute, in Troy, NY, are proposing a type of liquid lens--made of only two drops of water--that changes shape when bombarded with sound waves. Using sound requires much less power than previous methods and could, with improvements in resolution, make the lens attractive for use in small surveillance cameras and cell phones.
With glass, plastic, and other hard materials, it's impossible to quickly change the shape of the lens, and therefore to focus: to adjust the focal length, you need to physically move the lens. Extremely small cameras and many cell phones simply don't have enough room to allow users to move a rigid lens the distance required for a range of focal lengths. An adaptive liquid lens, however, enables small cameras to focus without needing any extra room. "Liquids are a favorite material to work with when you want to change the shape of a lens," says Amir Hirsa, a professor of mechanical and aerospace engineering at Rensselaer and lead researcher on the project.
The researchers' lens system, described in October's Nature Photonics, is composed of a Teflon cylinder less than two millimeters in diameter. The cylinder is overfilled with water so that droplets bulge out on either side. A speaker is hooked up to one side of the cylinder, which is in a pressure-sensitive chamber. The researchers pumped sound at between 50 and 160 hertz into the chamber, changing the shape of the droplet's surface.
Two companies, Philips and Varioptic, which is based in France, have developed products that use an alternative liquid-lens system. Both use two different liquids that are in contact with each other, which creates an imaging lens at the interface. In a process called electrowetting, the shape of the interface is altered when an electric current is applied to it, changing the surface tension of both liquids.
The advantage of his new approach, says Hirsa, is that it requires much less power. He says that electrowetting requires an electric potential of tens to one hundred volts is required to adjust the conventional liquid lens. In contrast, only a small potential of a couple of millivolts is required to drive his two-droplet design.
Fluid droplets could replace plastic lenses in cell-phone cameras, banishing blurry photos.
This technique seems to provide some depth information as the focus varies. Perhaps it could generate 3D images?
I think the idea behind Liquid lens is very genius. The fact that only two drops of h2o could potentially improve resolution, use less power than previous methods and have more physical appeal to their appearance is great. However I think before making the switch from glass and plastic to liquid they must meet the same picture quality. Although flexibility is essential, the quality of the object being captured matters the most. On that note, if liquid lens's are able to function without such a strict resolution it shall be a great technological advancement.
A great advancement and amazingly innovative. But the question is are people willing to sacrifice quality of resolution for the sake of saving energy. I'm sure that eventually they will find the solution for advancing the resolution, but until then i doubt that many will invest in liquid lens.
I think liquid lens are a pretty cool idea that will, in the future make glass lens obsolete. However, since the picture quality isn’t as good as the quality that comes from a picture made with glass lens, we still should use glass lens. When the technology is there to use liquid lens that are as good if not better than glass lens, then we should switch. The fact that these will be able to save energy will make them very useful in the long run when the picture quality has picked up
I think that this technology certainly has a place in the future. the efficiency that the liquid lens provides is certainly a great acheivement. however, without high picture quality, this technology won't take off as it would if the picture quality was good. i would love to see an improvement on this aspect of the technology.
liquid lenses seem like a good idea with the thought of energy in mind, but it seems like these liquid lenses can only be used for small devices like cell phones, rather than large screen tv's due to the loss in resolution. I think that it would be wise for cell phone companies to invest in liquid lens research because the cameras on cell phones now are pretty weak. My only concern is, will cell phones have the processing power to quickly pick the best shot out of the multiple ones taken?
liquid lens is a great idea. even though the resolution isnt as great, i believe that in the near future, humans are going to have to make necessary changes in their lifestyle that include saving energy. this has a definite place in the future.
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haruhi
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i guess another way of improving resolution is to have a software that could identify pixels that are in focus and stitch them together to create a clear picture of what is being taken...just thinking ^_^
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