Optofluidic lenses for 2D and 3D imaging

Abstract

Optofluidic lenses that modulate light using fluidic materials have been recognized as a powerful alternative to solid lenses. These lenses can achieve many advanced imaging capabilities that are difficult to achieve otherwise. In particular, such adaptive optical elements have shown great potentials in a broad array of applications in two-dimensional (2D) and three-dimensional (3D) imaging, including macro/microscopic imaging, optical coherence tomography, wide-angle imaging, spectral imaging, optical zooming, and switchable monocular/binocular vision. This article reviews current research efforts on optofluidic lenses for 2D/3D imaging. The configurations and actuation mechanisms of different types of optofluidic lenses and their representative imaging applications are introduced. The opportunities and challenges in this field are also discussed. This review is expected to provide a snapshot of the current landscape of optofluidic lenses research to attract more interests in this exciting field and foster the development of next-generation optofluidic lenses.

Temperature-dependent electrowetting behavior on Teflon AF1600

“…The dielectric-electrolyte contact angle is determined by the respective interface energies and the electric energy stored in the solid dielectric layer. Based on the benefits of EWOD, EWOD has been widely used in applications, for example, generating transporting and mixing small droplets in microfluidic devices [2][3][4], adjustable liquid lenses [4][5][6][7][8][9], etc. Different CAs are measured since the static CA can vary due to material and ambient-related factors, such as surface roughness [10], chemical inhomogeneity [11], adsorption and temperature [12,13].…”

Control of liquid crystals combining surface acoustic waves, nematic flows, and microfluidic confinement

“…[1][2][3][4] In particular, liquid crystals (LCs), which exhibit versatile and anisotropic optical properties associated with their alignment, provide attractive platforms for optofluidic applications. [5][6][7][8] LCs are highly sensitive to external stimuli, including electric and optical fields, and have been widely used in displays and photonic systems. [9][10][11] Recently, advances in nanofabrication techniques have created new opportunities for the combined application of multiple fields, such as ultrasound and flow.…”

Tunable and Dynamic Optofluidic Microlens Arrays Based on Droplets

“…16−20 Among them, liquid microlenses with tunable focal lengths, as individual components or arranged in arrays, have attracted intensive attention. 21,22 In general, the focal length is adjusted by controlling the size, 23 refractive index profile, 24,25 or fluidic interface of the liquid lenses. 26,27 Droplets, 28−31 and display intrinsic lensing behavior.…”

“…Optofluidics, taking advantage of microfluidics and micro-optics to control dynamic fluid materials and manipulate light on a chip, represents a novel and ideal platform to form versatile, responsive, adjustable optical components on a microscale. − Among them, liquid microlenses with tunable focal lengths, as individual components or arranged in arrays, have attracted intensive attention. , In general, the focal length is adjusted by controlling the size, refractive index profile, , or fluidic interface of the liquid lenses. , Droplets, − generated by the two immiscible liquid materials, form the curved interface between fluid volumes and display intrinsic lensing behavior. When interfacial stabilization is present, droplets can assemble into two-dimension arrays or three-dimensional structures. − Recent developments in optofluidics have led to the large-scale production of monodispersed liquid droplets with a range of functionalities, such as droplet-based compound microlenses composed of hydrocarbon and fluorocarbon liquids .…”