Axisymmetrical resonance modes in an electrowetting optical lens

Eduardo J Miscles; Wei Yang Lim; Omkar D Supekar; Mo Zohrabi; Juliet T Gopinath; Victor M Bright

doi:10.1063/5.0141787

Axisymmetrical resonance modes in an electrowetting optical lens

Appl Phys Lett. 2023 May 15;122(20):201106. doi: 10.1063/5.0141787. Epub 2023 May 17.

Authors

Eduardo J Miscles¹, Wei Yang Lim¹, Omkar D Supekar, Mo Zohrabi², Juliet T Gopinath, Victor M Bright¹

Affiliations

¹ Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA.
² Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA.

Abstract

Electrowetting-based adaptive optics are of great interest for applications ranging from confocal microscopy to LIDAR, but the impact of low-frequency mechanical vibration on these devices remains to be studied. We present a simple theoretical model for predicting the resonance modes induced on the liquid interface in conjunction with a numerical simulation. We experimentally confirm the resonance frequencies by contact angle modulation. They are found to be in excellent agreement with the roots of the zero-order Bessel functions of the first kind. Next, we experimentally verify that external axial vibration of an electrowetting lens filled with density mismatched liquids ( $Δ ρ$ = 250 kg/m³) will exhibit observable Bessel modes on the liquid-liquid interface. An electrowetting lens filled with density matched liquids ( $Δ ρ$ = 4 kg/m³) is robust to external axial vibration and is shown to be useful in mitigating the effect of vibrations in an optical system.