CAREER: Electrowetting Microprisms - from Agile Fresnel Optics to Wide-Angle Phased Arrays

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

Intellectual Merit. The objective of this CAREER proposal is to array electrowetting microprisms and create a form of flat electro-optics that has not existed before. Electrowetting microprisms voltage-modulate the contact angle between a saline liquid and a dielectric. This contact angle modulation can then be used to reconfigure the saline meniscus geometry and consequently the refraction of light. Specific research aims include: (1) silicon-integrate and stabilize long-channel devices; (2) array multiple devices into agile Fresnel optics and phase-continuous flat optics; (3) create novel AC drive schemes and feedback controls to increase accuracy. Leading intellectual issues include: (a) enabling flat electrowetting optics via a breakthrough in cylindrical meniscus stabilization; (b) creating the first electro-optical 2p-phase profile without need for multi-electrode step-indexing; (c) developing advanced controls for accurate multiplexing of numerous electrowetting devices; (d) demonstrating new optical tools for investigating microscopic electrowetting non-idealities. Broader Impact. The educational aims are: (1) amplify 3 months of NSF-supported sophomore research experience into 18 months of co-op research experience at one of four industrial research partners; (2) elevate the K-college educational experience by creating a highly-visible resource center for electrowetting education/science. Preliminary experiments support projections that electrowetting microprisms will provide performance leaps over liquid-crystal phased-arrays in the categories of steering angle (10X, >30), transmission efficiency at all polarizations (2X, >80%), and switching speed (100X, >10 kHz). These attributes are highly desired for applications such as beam steering for laser radar. Broader impacts include electrowetting microprisms as an enabler for networked solar-lighting and for agile endoscopy. The improved understanding provided by this project will allow the PI to expand electrowetting into projects such as switchable photonic crystals and ultra-accurate liquid sampling for lab-on-chip.