Achieving Directional Oil Manipulation by Open Inducing Structure for Electrowetting Displays

ABSTRACT Oil movement control is crucial for optimizing the optical performance of electrowetting display (EWD) devices. Herein, an open inducing structure (OIS) is introduced, which is directly formed by photoembossing of dielectric layer materials into EWD pixels, aiming to regulate oil dynamics by inducing local electric field inhomogeneity. The OIS is designed with a frustum‐shaped profile, circumventing secondary processing requirements and abrupt aperture ratio changes associated with traditional cylindrical notch structures. Optimal height of OIS is in the range of 10%–30% of the pixel wall height. Utilizing photoembossing combined with predefined mask patterns enables precise control of the structure's position, quantity, and height. Experimental results demonstrate that this OIS effectively reduces the oil aperture voltage, guides directional oil movement, and enhances the device's optoelectronic performance without compromising the aperture ratio. This study provides a versatile and scalable oil control strategy for EWD devices, offering broad device compatibility.