Title :
Tunable liquid micro-lens system
Author :
Krogmann, Florian ; Moench, Wolfgang ; Zappe, Hans
Author_Institution :
Lab. for Micro-optics, Freiburg Univ., Germany
Abstract :
Electro-wetting technology has become a promising approach for the fabrication of liquid micro-lenses with tunable focal length. By applying a voltage between a liquid droplet and an electrode covered by an insulating layer, the surface free energy, and thereby the contact angle of the droplet, is modified. By embedding the droplet in a fluid of the same density, the influence of gravity can be removed and a maximum of mechanical stability can be reached. A novel, tunable liquid micro-lens system fabricated in MEMS technology is presented and characterization results using three kinds of liquids, including an equal-density fluid system, are presented. The back focal length of this latter system can be tuned between 2.3 mm and infinity with applied voltages of 0 V to 45 V.
Keywords :
contact angle; microlenses; micromachining; micromechanical devices; optical fabrication; optical tuning; wetting; 0 to 45 V; MEMS technology; back focal length; droplet contact angle; electro-wetting technology; equal-density fluid system; mechanical stability; surface free energy; tunable focal length; tunable liquid micro-lens fabrication; Adaptive optics; Dielectric liquids; Dielectric substrates; Electrodes; Equations; Glass; Lenses; Optical refraction; Tunable circuits and devices; Voltage;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05. The 13th International Conference on
Print_ISBN :
0-7803-8994-8
DOI :
10.1109/SENSOR.2005.1496627
