Double Sided-Design of Electrodes Driving Tunable Dielectrophoretic Miniature Lens

We demonstrate the design methodology, geometrical analysis, device fabrication, and testing of a double-sided design (DSD) of tunable-focus dielectrophoretic liquid miniature lenses. This design is intended to reduce the driving voltage for tuning the lens, utilizing a double-sided electrode design that enhances the electric field magnitude. Fabricated devices were tested and measurements on a goniometer showed changes of up to 14° in the contact angle when the dielectrophoretic force was applied under 25 V_rms. Correspondingly, the back focal length of the liquid lens changed from 67.1 mm to 14.4 mm when the driving voltage was increased from zero to 25 V_rms. The driving voltage was significantly lower than those previously reported with similar device dimensions using single-sided electrode designs. This design allows for a range of both positive and negative menisci dependent on the volume of the lens liquid initially dispensed.