New - Liquid Lenses
Posted: Sun Mar 27, 2005 10:40 amExerpted from the April 2005 Issue of WIRED Magazine:
"....the ideal optical setup would be small, soft, and adaptable, like the human eye. So cell phone makers are salivating over liquid lenses, tiny gadgets that suspend a drop of liquid in an electrostatic field. Change the field and the shape of the droplet changes, too, altering how the light bends when it passes through -just like a lens.
It works because of a property called wettability: On hydrophilic surfaces, water sticks and spreads out; on hydrophobic surfaces, water is repelled, so it beads up to minimize contact area. But varying electrical voltage across the water droplet changes its response to the surface; in essence, you can dial wettability up or down, changing the shape of the droplet-lens on the fly. You end up with an optical power 5 to 10 times greater than the human eye, and response that's up to 20 times faster."
Varioptic in Lyon, France, combined salt water and an oil with the same density but different optical properties. The oil forms the lens; the water changes shape to control it. Meanwhile, Philips Research in the Netherlands is aiming its FluidFocus lenses at higher-end applications, like optical zooms for digital cameras. In a typical camera, a zoom is a kind of telescope: lenses at each end with a variable distance between them. Philips instead assembles three lenses, two plastic and one liquid with a glass core. The core doesn't change, but the liquid can alter the overall lens shape dramatically. Result: a miniature, high-powered zoom."
Full article on page 34 of Wired Magazine, April 2005
"....the ideal optical setup would be small, soft, and adaptable, like the human eye. So cell phone makers are salivating over liquid lenses, tiny gadgets that suspend a drop of liquid in an electrostatic field. Change the field and the shape of the droplet changes, too, altering how the light bends when it passes through -just like a lens.
It works because of a property called wettability: On hydrophilic surfaces, water sticks and spreads out; on hydrophobic surfaces, water is repelled, so it beads up to minimize contact area. But varying electrical voltage across the water droplet changes its response to the surface; in essence, you can dial wettability up or down, changing the shape of the droplet-lens on the fly. You end up with an optical power 5 to 10 times greater than the human eye, and response that's up to 20 times faster."
Varioptic in Lyon, France, combined salt water and an oil with the same density but different optical properties. The oil forms the lens; the water changes shape to control it. Meanwhile, Philips Research in the Netherlands is aiming its FluidFocus lenses at higher-end applications, like optical zooms for digital cameras. In a typical camera, a zoom is a kind of telescope: lenses at each end with a variable distance between them. Philips instead assembles three lenses, two plastic and one liquid with a glass core. The core doesn't change, but the liquid can alter the overall lens shape dramatically. Result: a miniature, high-powered zoom."
Full article on page 34 of Wired Magazine, April 2005
