Operating mode of liquid lenses

The liquid lenses developed by VARIOPTIC are based on the phenomenon of elec­tro-wetting. A water drop lies on a metallic substrate, which is covered by a thin insulation layer. The voltage applied between substrate and water drop varies the contact angle between water drop and substrate. Liquid lenses from VARIOPTIC use two liquids, one of which is used as an insulator, while the other one is used as conducting layer. Varying the applied voltage leads to a change in bend of the border layer between both liquids. This causes a change in focal length of the lens. VARIOPTIC owns two fundamental, worldwide patents about this technology

and is dedicating a large part of their development capacity to the improvement and expansion of these patents.

Characteristics of liquid lenses:

• Large range of focal length
• Robust – no moving components
• Short reaction time
• Very good optical quality
• Good transmission in the range of visible wavelengths
• Large range of operating temperature
• Very good stability of the optical axis
• Low power consumption
• Simple, cost-saving design

Field of application:

For future mobiles, PDAs, etc.

According to the technology used, VARIOPTIC’s optically controlled lenses are also called liquid lenses. Liquid lenses are well-suited for the next generation of mobile devices with camera function: mobiles, PDAs, digicams and many more. The VARIOPTIC-technology offers some key benefits for this type of devices:

• Very small size: 8 mm in diameter, thickness of 2 mm
• simple design
• short reaction time <2/100 s
• low power consumption

Medical technology

The big potential of VARIOPTIC with refer­ence to miniaturisation creates many new opportunities in the area of imaging. So, liquid lenses are, for instance, suitable for installation inside endoscopes, confocal microscopes and for laser focusing. Oph­thalmology will also benefit from this new technology of liquid lenses.

Biometry and identification

The short reaction time of 2/100 s is an essential benefit for recognising specific features: barcodes or biometric character­istics like iris or finger prints.

The manufacturer:

VARIOPTIC is a leading enterprise in development and manufacturing of electronically

controlled liquid optical lenses for the optical industry. VARIOPTIC is, for instance, the first enterprise which was granted international patents for a single-component focusing lens, which is based on non-mixable liquids. In order to retain and to further develop their technological head start, VARIOPTIC invests increasingly in research and development.

VARIOPTIC has its headquarters in Lyon, in France, and was founded in 2002.