The adaptive liquid lens is based on a new electrically responsive fluid called dibutyl adipate (DBA) that changes focal length when a voltage is applied.
The lens is lightweight, compact and simple to fabricate, which makes it ideal for mobile phone cameras, endoscopes, eyeglasses and machine vision applications, the researchers said in a paper published in the scientific journal Optics Letters.
“The human eye can arbitrarily focus on objects at different distances at incredibly fast speeds,” said research team leader Miao Xu from Hefei University of Technology in the Eastern Chinese city of Hefei. “Inspired by this functionality, we developed an eye-like adaptive liquid lens that can be used to diverge or converge light by changing the shape of the DBA liquid.”
According to the research team the DBA-based adaptive liquid lens, which weighs just a few grams, exhibits high optical performance with good stability.
DBA’s electronegative molecular structure allows an applied voltage to be used to rapidly change the lens’ shape to modify its focal length. The fluid is also transparent, non-volatile and inexpensive, making it ideal for use in adaptive liquid lenses, the researchers said.
“This type of adaptive liquid lens could one day replace conventional solid lens systems,” said Xu. “This would enable a mobile phone camera that can rapidly change focal length while still being as thin as the phone itself.” Because it doesn’t require any mechanical elements, this type of lens can be used for years without wearing out.”