Dynamic simulation of bistable electrofluidic device based on a combined design of electrode and wettability patterning

Abstract

Electrowetting has shown its power in manipulating microfluidics. Of particular interest is a bistable electrowetting system, which enables versatile low power consumption applications. A combined design of electrode and wettability patterning, which includes a unique three‐electrode structure and wettability barrier, was proposed and introduced into as a new electrofluidic display (EFD) architecture. This architecture should be manufacturable in a fairly straightforward way within LCD cell‐making technology. For this architecture, an electrohydrodynamic two phase flow simulation was carried out using the COMSOL Multiphysics simulation software. The results show that this new EFD architecture could achieve a bistable display property. Compared with conventional EFD, the electro‐optical performance (the aspect ratio and response time) of this design has also been greatly improved.

Inkjet-printed patterned polytitanosiloxane-fluoropolymer composite dielectric layer for micro-optical electrowetting valves

“…A 2D model of the micro-well was built in COMSOL Multiphysics, and the two-phase electro-hydrodynamic simulation was carried out to study the dual-fluid motion [28]. Material, interfacial, and geometric properties are shown in table 1.…”

“…Dou et al [27] introduced an extra pinning structure into the electrofluidic device to control the oil motion inside the pixels. Zhao et al [28] designed a novel barrier structure to control the switching behavior of the oil film in an electro-fluidic device. Chen et al [29] introduced an extra hydrophobic/hydrophilic magnetic particle on the hydrophobic layer to rearrange the oil film distribution in electrowetting devices and obtained high efficiency and position controllable multiway light valves.…”

“…In this study, an organic-inorganic hybrid dielectric material, polytitanosiloxane, was patterned in each micro optical valve of the OEWD via inkjet printing. Compared with the previous works which focused on the barrier or pinning structures above the hydrophobic fluoropolymer layer [27][28][29], we used this patterned polytitanosiloxane layer as an extra insulator under the hydrophobic fluoropolymer coating and a functional structure to control the fluid flow in the micro valve by rearranging the electric field distribution. The effects of different structural parameters of the inkjet-printed polytitanosiloxane (IPP) layer on the fluid motion at the microscopic level and the macroscopic visual performances of the device were studied experimentally.…”