Abstract
Oil motion control is the key for the optical performance of electro-fluidic displays (EFD). In this paper, we introduced an extra pinning structure (EPS) into the EFD pixel to control the oil motion inside for the first time. The pinning structure canbe fabricated together with the pixel wall by a one-step lithography process. The effect of the relative location of the EPS in pixels on the oil motion was studied by a series of optoelectronic measurements. EPS showed good control of oil rupture position. The properly located EPS effectively guided the oil contraction direction, significantly accelerated switching on process, and suppressed oil overflow, without declining in aperture ratio. An asymmetrically designed EPS off the diagonal is recommended. This study provides a novel and facile way for oil motion control within an EFD pixel in both direction and timescale.
Highlights
Electrowetting has shown its power in manipulating micro-fluidics, which inspired applications like microfluidic chips [1,2] as well as electro-fluidic displays (EFD) [3]
This paper provides a novel and facile way for oil motion control, which opens a new perspective for the optimization of EFD optical performance in both uniformity and response
According to our previous study [16], the pixel switching on process can be divided into three separate stages: oil film rupture, oil dewetting, and oil rearrangement, which could be described by wavelength selection [17], linear dewetting, and coarsening process, respectively
Summary
Electrowetting has shown its power in manipulating micro-fluidics, which inspired applications like microfluidic chips [1,2] as well as electro-fluidic displays (EFD) [3]. EFD pixel (Figure 1), which is sub-millimeterin size, the dominant driving forces for oil motion are recognized as interfacial tension and electrostatic force [12]. Where θ is the voltage-dependent contact angle in electro-fluidic display, θY is the Young’s angle without voltage, σ is the interfacial tension between oil phase and water phase, c is the capacitance per unit area between the water phase and the electrode, and U is the applied voltage. When a voltage is applied to the electro-fluidic pixels (Figure 1b), the electrostatic force drives conductive liquid (water in our case), wetting the insulator surface, and pushing the oil motion. The oil motion during the on-switching process presents the optical response of the EFD, which could be characterized by the change in the white area percentage (WA) [13]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
