Cameras and phones of a decreasing size and weight are hard to supply with a solution that is simpler, cheaper, lighter and has the same quality as glass lenses. Japanese Seiko and French Varioptic have announced this March their lens made of oil and water, but researchers at Rensselaer Polytechnic have announced an even simpler and cheaper solution that requires less energy than previous technologies and it needs no high voltage. The new solution uses two drops of water for focusing that is resonated with high-frequency sound. A proper algorithm can then select the pictures in focus, disregarding others. Amir H. Hirsa, leader of the research project has said that most liquid lens currently in use focus by manipulating the shape and size of the liquid's surface, which doesn't only require more energy, but also more time. The new technology uses only two drops of water that are placed on the two ends of a cylinder. When used a sound of an appropriately high frequency, making use of the water's natural surface tension and inertness, the system becomes a kind of oscillator, a miniature pendulum. The water drops resonate at a high frequency forwards and backwards, just as if they were attached to a spring. As the light strikes through the two water drops it behaves just as if it was passing through a lens system.
As the effect of the continuous resonation of the water drops in the cylinder, the details in the focus change and a proper software could select those images where the wanted detail is in focus. With the use of sound of a different frequency, the frequency of the water drops can be alterd, but the size of the drops can highly influence the frequency of the oscillation. According to Hirsa when using drops of a proper size an oscillation of one hundred thousand per second can be achieved, during which the selection of focused pictures can be solved with a high efficiency. Hirsa expects the mobile phone manufacturers to be interested too, as they are also looking for the smallest, high-quality solutions with a low consumption solution. The report didn't yet cover how can the lens be helped when taking pictures in darkness, as the lens system has to kepp a given picture in focus for up to one tenth of a second.
Translated by Szaszati
