High speed adaptive liquid microlens array

Abstract

Liquid microlenses are attractive for adaptive optics because they offer the potential for both high speed actuation and parallelization into large arrays. Yet, in conventional designs, resonances of the liquid and the complexity of driving mechanisms and/or the device architecture have hampered a successful integration of both aspects. Here we present an array of up to 100 microlenses with synchronous modulation of the focal length at frequencies beyond 1 kHz using electrowetting. Our novel concept combines pinned contact lines at the edge of each microlens with an electrowetting controlled regulation of the pressure that actuates all microlenses in parallel. This design enables the development of various shapes of microlenses. The design presented here has potential applications in rapid parallel optical switches, artificial compound eye and three dimensional imaging.

Deformation of a nearly hemispherical conducting drop due to an electric field: Theory and experiment

“…41 In this geometry, the fluid fills the region between the electrodes and the upper electrode has an array of aperture holes through which the fluid protrudes, forming spherical and aspherical microlenses with pinned contact lines. In addition, future theoretical and experimental work will consider the dynamic response of a sessile drop immediately after the abrupt application and the abrupt removal of a voltage.…”

A numerical technique to simulate display pixels based on electrowetting

“…The electric fields lead to a Maxwell stress pulling on the liquid-liquid interface. In recent years, electrowetting (Mugele and Baret 2005) has evolved into the arguably most popular technique for electrical manipulation of liquids in microfluidics with a wide range of applications including lab-on-a-chip systems (Fair 2007), optofluidics (Berge and Perseux 2000;Kuiper and Hendriks 2004;Krupenkin et al 2003;Murade et al 2011Murade et al , 2012, energy harvesting (Krupenkin and Taylor 2011) and display technology (Hayes and Feenstra 2003;Sun and Heikenfeld 2008). Electrowetting on dielectric (EWOD) involves a specific geometry with a thin dielectric coating separating an electrode from the conductive liquid sitting on top of it ( Fig.…”

Adaptive Liquid Lens Actuated by Droplet Movement

“…According to the difference of the filled materials, it can be roughly classified into two categories: liquid crystal (LC) lens [1][2][3][4][5] and liquid lens [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. An adaptive LC lens usually employs an OPEN ACCESS inhomogeneous electric field to make the LC molecules reorient to produce a gradient refractive index profile.…”

“…Since the response time depends on the LC layer thickness and the size of the LC lens, it is more suitable for making microlens which constrains the real applications in imaging systems. There are three common operating mechanisms to design a liquid lens: electrowetting effect [6][7][8][9][10][11][12][13][14], dielectric force [15][16][17][18], and fluidic pressure [19][20][21][22][23][24].…”