Design and fabrication of hexagonal electrowetting multifunctional liquid lens

In this paper, a hexagonal electrowetting multifunctional liquid lens (HEM-LL) was designed and fabricated. The shell of HEM-LL is a regular hexagonal prism with a bottom side length of 5 mm and a height of 10 mm. The bottom and six side walls are made of conductive glass, offering six independently controllable electrodes. The cavity contains equal volumes of two immiscible liquids (one conductive and the other non-conductive) with similar densities, whose interface morphology can be altered by the electrowetting effect. The device demonstrates long-term operational stability with a voltage range of 0 V to 200 V. The higher degree of freedom in electrode control enables HEM-LL to possess both the capabilities of focal length tuning and beam deflection control. When the six applied voltages are identical, HEM-LL operates in the mode of a lens. By synchronously adjusting the applied voltages, continuous zooming within the range of (-∞, -32.9 mm) can be achieved. When the applied voltages are not entirely the same but meet certain matching relationships, HEM-LL can function as a prism. By modulating the voltages, a beam steering angle between -3.66° and 3.66° are attainable in multiple directions. In addition to the tunable multi-functionalities of both a lens and a prism, the regular hexagonal prism shape of HEM-LL also facilitates the assembly of arrays. The demonstrated functionality shows promise for diverse applications requiring integrated imaging and beam control, such as specialized photography, dynamic metrology, and solar energy concentration systems.