Dielectrically actuated liquid lens

Abstract

A packaged liquid lens driven by the dielectric force was demonstrated. The liquid lens consisted of a low dielectric constant droplet and a high dielectric constant sealing liquid. The two non-conductive liquids were sealed in a chamber under the condition of iso-density. Focal length of a liquid lens with an aperture of 3mm changed from 34mm to 12mm in the range of 0-200V. Hysteresis was observed in the liquid lens, with a maximum value measured of 12.5 degrees at 120 volts in terms of droplet's contact angle. The focal spot size measured approximately 80mum. Rise and fall times were 650ms and 300ms, respectively. The lens consumed 1mW of power when applying a 200 volt, 1 kHz signal. The longitudinal and transverse spherical aberrations were estimated to be nearly invariant when the focal length exceeded 20mm.

Analysis of a static undulation on the surface of a thin dielectric liquid layer formed by dielectrophoresis forces

“…The potential in the oil layer and the potential in the air region will be described by series expansions of Fourier modes given in equations [3] and [4] respectively. The coefficients of higher order modes for which n > 3 are all zero to first order in Ak since the periodic potential at the lower boundary and the deformation at the oil/air interface (equation [1]) are both single mode sinusoidal functions of the coordinate x.…”

“…where equations [3] and [4] both obey the Maxwell equation [2]. At the liquid/air interface the electrostatic boundary conditions obtain that the tangential component of the electric field and the normal component of the displacement field must both be continuous,…”

“…Expressions for the coefficients in equations [3] and [4] are derived by matching the electrostatic boundary conditions at the liquid/air interface y = h(x) and at y = 0 where the spatially periodic potential…”

“…Expressions are given below for the coefficients of the Fourier modes a 1 , a 3 , b 1 and b 3 in equation [3] and c 1 , and c 3 in equation [4] to first order in Ak.…”

Activation and control of microlens liquid arrays on functionalized polar electric crystal substrates by electro-wetting effect and temperature

“…The applied voltage changes the equilibrium among the forces acting on the liquid-liquid and solid-liquid interfaces causing a changing in the curvature of the meniscus at the liquid-liquid interface. In this way, the applied voltage variation allows to switch between converging and diverging lens with flexible focal lengths [2][3][4][5][6][7]. In some cases a free standing sessile liquid drop is placed on a plane surface acting as first electrode while the second one is a [8].…”