Electrically Tunable Lenses for Imaging and Light Manipulation

Abstract

Optofluidics seamlessly combines optics and microfluidics together to construct novel devices for microsystems, providing flexible reconfigurability and high compatibility. By taking advantage of mature electronic fabrication techniques and flexible regulation of microfluidics, electrically actuated optofluidics has achieved fantastic optical functions. Generally, the optical function is achieved by electrically modulating the interfaces or movements of microdroplets inside a small chamber. The high refractive index difference (~0.5) at the interfaces between liquid/air or liquid/liquid makes unprecedented optical tunability a reality. They are suitable for optical imaging devices, such as microscope and portable electronic. This paper will review the working principle and recent development of electrical optofluidic devices by electrowetting and dielectrophoresis, including optical lens/microscope, beam steering and in-plane light manipulation. Some methods to improve the lens performance are reviewed. In addition, the applications of electrical microfluidics are also discussed. In order to stimulate the development of electrically controlled liquid lens, two novel designs derived from electrowetting and dielectrophoresis are introduced in this paper.

Study on the Formation and Controllable Movement of Polymer Liquid Columns Based on Dynamic Control of Spatial Electric Field Distribution

“…These adapting techniques on controllable polymer micropatterns provide advanced fabrication tools with high-precision capabilities but need sophisticated and costly processes and equipment. Since that electrowetting manipulation and movement/deformation of liquids can be driven only through the change or adjustment of the electrical signals, it exhibits very extraordinary high research value and attracts much research interest. − It was discovered that dielectric liquid is unstable in the electric field generated by two parallel electrodes for a long time. , Dielectric liquid can be pulled into the air gap of two parallel electrodes when a voltage is applied to both electrodes. − A large number of scholars have studied the use of this phenomenon to liquid films unstable and have prepared various polymer array microstructures, such as some circular arrays . Hwang et al fabricate periodic line microstructures at the submicron scale. , Vespini et al produced various microlens arrays .…”

Study on a Noncontact Microdroplet Separation Method under the Action of Corona Discharge

“…Since the advent of microelectro-mechanical systems (MEMS), liquid objects on the microscale have been widely used and studied . Different from rigid solid objects, liquid objects are intrinsically divisible, enriching their fundamental operations with merging, dispensing, and splitting. , Electrowetting manipulation of liquids has attracted considerable interest because it does not require any physical pumps or valves, and movement or deformation of liquid only through changes in electrical signals. , Precision manipulation of various liquids is essential in many fields, such as various thermal, optical, and medical applications. − Liquid manipulation in a precise and programmed manner is crucial for stoichiometry, biological assays, combinatorial analysis, and intelligent lab-on-a-chip . As a result, it needs to separate droplets in a specific arrangement and morphology …”