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

Abstract

Fluid motion control has always been essential in electrowetting devices. Using the inkjet printing technique, an organic-inorganic hybrid material, polytitanosiloxane, was patterned as a secondary dielectric under the hydrophobic fluoropolymer coating in an optical electrowetting device (OEWD). The effects of different structural parameters of the inkjet-printed polytitanosiloxane (IPP) layer on both the fluid motion at the microscopic level and the macroscopic visual performances of the device were studied experimentally. The leakage-current test was also performed to evaluate the insulating performance of the composite dielectric layer. In addition, COMSOL Multiphysics was used to simulate the fluid flow inside the OEWD with/without the polytitanosiloxane layer. The results showed that, by introducing this IPP layer, precise fluid motion control and improved performance could be obtained.

High Dielectric Nonpolar Interfacial Layers Derived from Nanocellulose for Electrowetting Devices

“…The preparation of the electrowetting display device was used the same way as previously reported. [ 25 ] The process consists of three steps: cover plate preparation, substrate preparation, filling, and assembling. PTFEMA@CNC solution was spin‐coated on the ITO surface, while the thickness was controlled at ≈800 nm.…”

67‐3: Invited Paper: Progress in Electronic Paper Displays: Color Video Electrofluidic Display Technology

“…[9] Furthermore, we proposed a liquid container model that comprises a hydrophobic dielectric polytitanosiloxane (IPP), colored oil and an electrically conducting aqueous phase (water). [10] Two surface electrodes were placed at the bottom and the top of the micro-well. From the 2D simulation results of the pressure field distribution inside the micro-wells with 10% IPP and 50% IPP (3-layers), the IPP would rearrange the electric field distribution in the dual-liquid layer and lead to the initial rupture point above the IPP layer (Figure 4).…”

“…Schematic diagrams of the oil rupture states and simulated images of pressure field distribution in the microwell with 10% IPP and 50% IPP. [10]…”

“…[10] In addition, considering the dielectric constant of polytitanosiloxane IPP (13-16) was much higher than that of AF (1.9-2.1), we used this organic-inorganic hybrid material patterned as a secondary dielectric under the hydrophobic fluoropolymer coating in an optical electrowetting device (Figure 7). [10] It showed that the presence of composite dielectric layer can increase the response speed of the EFD. The I-V test showed the IPP also improved the isolating property of the composite dielectric layer and decreased the leakage current after aging tests.…”

Programmable Control of Two‐Phase Fluid Interface Relative Motion in Electrowetting Device

“…[8] Zhou et al manipulated the oil rupture voltage by varying the thickness of the local dielectric layer in the electrowetting device. [9] Another method was to disturb the homogeneity of the liquid layer by inserting microstructures with opposite wettability. Shui et al tried to control the oil film rupture location by adjusting the oil film distribution in the pixel where the thickness of the oil film around the magnetic particles depended on the wettability of the particles.…”