Novel dual-function lens with microscopic and vari-focus capability incorporated with an aberration-suppression aspheric lens

Abstract

Substantial aberrations are ubiquitous in many conventional adaptive lenses due to the existence of deformable interface and thus inevitably compromise the optical performance. In this paper, we introduce a novel concept of dual-function fluidic lenses (DFFL) with a built-in aspheric polydimethylsiloxane lens (APL) to enable the design of a compact optical system with tunable imaging and aberration suppression properties. This is achieved by varying both hydrostatic pressures (i.e. adjusting the injected liquid volume change) such that a widely tunable focal length and the simultaneously integrated APL for aberrations correction. DFFL can transform to 4 modes: microscopic mode (APL only), APL/concave mode, APL/plano mode, and APL/convex mode. Focal tunability of DFFL from 12/8 mm to about 90/65 mm (DI water/ethanol) is demonstrated without any mechanical moving components. Aberration characterization is carried out systematically and the low cost, high performance microscopic mode can be easily achieved by actuating the contact between APL and PDMS membrane. In addition, DFFL turning to microscopic mode (focal length 7.32 mm and magnification 50X) can rival the images quality of commercial microscopes.

A lab-on-phone instrument with varifocal microscope via a liquid-actuated aspheric lens (LAL)

“…A crucial component of the LAL is an aspheric PDMS lens membrane composite (APLMC), which can be liquid-actuated to change the focal length. The fabrication process of PDMS membrane is similar to aforementioned APL [ 7 , 8 ] and the fabricated thickness ~500 μm. The top and bottom fluidic chamber serves as a rigid frame and made by acrylic cylinder (1 mm thick) which has the diameter and height of 10 mm and 3.5 mm, respectively.…”

“…Previously cured at lower temperatures ~70°C, PDMS droplets require a longer time (~1hr) to thermally cure the viscous liquid across the surface by balancing the equilibrium of gravity- pulled liquid surface. [ 7 , 8 ]. In this paper, an accelerated and heat-assisted curing is proposed.…”

“…Several industrial applications were reported previously included reconfigurable dielectric liquid droplet [ 3 ], optical beam control [ 4 ] and optical zoom [ 5 ]. Varifocal endoscopy with piezoelectric actuator [ 6 ] and smartphone enabled microscope [ 7 – 9 ].…”

Numerical analysis of electrically tunable aspherical optofluidic lenses

“…Intra-ocular lenses [16] have also been designed and developed using Zemax to provide solutions in ophthalmic applications. Fuh and Chen [17] designed and constructed an optical system comprising an aspheric PDMS lens with aberration control properties. Lima et al [18] numerically estimated the optical properties of electrically tunable astigmatic lenses.…”