Mechanical modeling of fluid-driven polymer lenses.

Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, Florida 33124, USA.
Applied Optics (Impact Factor: 1.69). 08/2008; 47(20):3658-68. DOI: 10.1364/AO.47.003658
Source: PubMed

ABSTRACT A finite-element model (FEM) is employed to study the pressure response of deformable elastic membranes used as tunable optical elements. The model is capable of determining in situ both the modulus and the prestrain from a measurement of peak deflection versus pressure. Given accurate values for modulus and prestrain, it is shown that the two parameters of a standard optical shape function (radius of curvature and conic constant) can be accurately predicted. The effects of prestrain in polydimethylsiloxane (PDMS) membranes are investigated in detail. It was found that prestrain reduces the sensitivity of the membrane shape to the details of the edge clamping. It also reduces the variation of the conic constant with changes in curvature. Thus the ability to control the prestrain as well as thickness and modulus is important to developing robust optical designs based on fluid-driven polymer lenses.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, the dynamic mechanical stability of the liquid-filled lenses was studied, in which acoustic excitation was used as broad band perturbation sources and the resultant response of the lens was characterized using non-contact laser Doppler vibrometer. To the best of our knowledge, it's the first time that the mechanical stability of liquid-filled lenses was experimentally reported. Both experimental results and theoretical analysis demonstrate that the resonance of the lens will shift to higher frequency while the vibration velocity as well as its magnitude will be reduced accordingly when the pressure in the lens cavity is increased to shorten the focal length. All of these results will provide useful references to help researchers design their own liquid-filled lenses for various applications.
    Optics Express 10/2012; 20(21):23720-7. · 3.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The theory of third-order aberrations for a system of rotationally symmetric thin tunable-focus fluidic membrane lenses with parabolic surfaces is described. A complex analysis of the third-order design of tunable fluidic lenses is performed considering all types of primary aberrations. Moreover, formulas are derived for the calculation of the change of aberration coefficients of the parabolic tunable fluidic membrane lens with respect to the wavelength. It is shown that spherical aberration of a simple tunable-focus fluidic membrane lens with parabolic surfaces can be corrected, which is not possible with a classical spherical lens. The presented analysis is explained on examples. Derived formulas make possible to calculate parameters of optical systems with fluidic membrane lenses with small residual aberrations.
    Applied Optics 04/2013; 52(10):2136-44. · 1.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A variable focal length liquid-filled lens (VFLLFL) is a lens that changes its focal length by modifying the amount of water contained on it. Recent studies show that the use of VFLLFL in micro-optical devices makes them light, simple and compact. The VFLLFL under study is composed of a cylindrical metal mount with a compartment for two elastic membranes and a liquid medium between them. Unlike previous studies that have focused on developing micro-lenses filled with liquid and with thin flat membranes, this paper presents the design, simulation, and analysis of the opto-mechanical behavior of the VFLLFL formed with thick membranes of different profiles and 2 cm diameter. The study considered three lenses with membranes of different profiles. To do so, a preliminary optical design was done of the lenses to reduce the spherical aberration; next, the study describes the modeling, simulation, and analysis of the mechanical behavior of the VFLLFL using FEM. Then a Genetic Algorithm application was developed to obtain the geometrical parameters of the lens when the shape changes due to pressure applied by the liquid medium on the internal surfaces of the membranes. Finally, with the initial geometrical parameters which the lens begins to adjust due to changes of pressure, an analysis and simulation were done of the optical behavior of the lenses using the OSLO commercial ray-trace program. The results obtained are shown.
    Optik - International Journal for Light and Electron Optics 06/2013; 124(11):1003–1010. · 0.77 Impact Factor


Available from
Jun 4, 2014