Miniaturization of dielectric liquid microlens in package

Abstract

This study presents packaged microscale liquid lenses actuated with liquid droplets of 300-700 m in diameter using the dielectric force manipulation. The liquid microlens demonstrated function focal length tunability in a plastic package. The focal length of the liquid lens with a lens droplet of 500 m in diameter is shortened from 4.4 to 2.2 mm when voltages applied change from 0 to 79 V rms . Dynamic responses that are analyzed using 2000 frames/s high speed motion cameras show that the advancing and receding times are measured to be 90 and 60 ms, respectively. The size effect of dielectric liquid microlens is characterized for a lens droplet of 300-700 m in diameter in an aspect of focal length.

Two Orders of Magnitude Improvement in Detection Limit of Lateral Flow Assays Using Isotachophoresis

“…Therefore, to improve the detection limits and slow binding rates in an immunoassay, preconcentration of the target becomes a necessary step. [26][27][28] A number of strategies are currently available to improve detection limits of the surface reaction in biosensors using preconcentration, including solidphase extraction, 29,30 electrokinetic techniques, 31,32 as well as chromatographic and membrane preconcentration. [33][34][35] Electrokinetic techniques address the target preconcentration with minimal requirements and pretreatment of the sample.…”

Double-Sided Design of Electrodes Driving Tunable Dielectrophoretic Miniature Lens

“…Above all, dielectric lenses overcome the electrolysis issue encountered in electrowetting lenses [15]–[17]. Both mechanisms, nonetheless, usually require high voltage levels exceeding 100 V rms or even reaching 200 V rms as in [15]–[24]. Some efforts were directed towards overcoming this barrier as reported in [25]–[27].…”

Fully developed contact angle change of a droplet in liquid actuated by dielectric force

“…11,12 Two electrohydrodynamic forces, widely applied to actuation of microscale droplets either in air or in liquids, are electrowetting/electrowetting on dielectric (EWOD) 13,14 and dielectric force. [15][16][17][18][19][20] Electrowetting is exerted due to the interaction between free charges in liquids and electric fields applied while the dielectric force is imposed on the interface of two dielectric (i.e., non-conductive) media due to the difference of dielectric constants. Non-uniform electric fields are applied to effectively adjust the contact angle of droplets.…”