Variable-focus Liquid Lens Based on a Laterally-integrated Thermopneumatic Actuator

  • Lee, June Kyoo (Graduate School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Park, Kyung-Woo (Graduate School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Lim, Geunbae (Department of Mechanical Engineering, Pohang University of Science and Technology) ;
  • Kim, Hak-Rin (Graduate School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Kong, Seong Ho (Graduate School of Electrical Engineering and Computer Science, Kyungpook National University)
  • Received : 2011.12.28
  • Accepted : 2012.02.14
  • Published : 2012.03.25


We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.


Supported by : National Research Foundation of Korea


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