Design and fabrication of PMMA-micromachined fluid lens based on electromagnetic actuation on PMMA–PDMS bonded membrane

Abstract

The fabrication of a poly(methyl methacrylate) (PMMA)-micromachined fluid lens with an optimally designed built-in electromagnetic actuator was demonstrated in this study. Through a finite element method, the number of winding turns and the distance between magnetic moments were estimated to design an effective and miniaturized electromagnetic actuator. The lens body composed of PMMA structures was simply and rapidly micromachined using computer numerical control micro-milling. The poly(dimethylsiloxane) (PDMS) membranes for electromagnetic actuation were bonded to the PMMA structures by using the proposed PMMA-PDMS bonding technique, which uses an SiO 2 intermediate layer. A physical repulsive force produced by the electromagnetic actuator applies a controllable fluidic pressure to a fluidic chamber that is sealed with the PDMS membrane, thus allowing dynamic focusing. The focus tunability of the fabricated lens was 67 diopters with a focus hysteresis of less than 1 mm and a response time of 2 ms. The solenoid of the built-in actuator showed negligible thermal crosstalk to the lens.

Tunable Fabry-Perot Interferometer Designed for Far-Infrared Wavelength by Utilizing Electromagnetic Force

“…The permanent magnet was fabricated in a cylindrical shape with a 2-mm diameter and 2-mm height. Aluminum, which is a paramagnetic material with a 1-mm diameter, was used as the core of the solenoid; depending on the 200 and 300 winding turns of the coil having a 50-μm thickness, the diameter of the solenoid is 2 mm and 2.6 mm, respectively, and the height is 2 mm [ 29 ]. In the lower solenoid structure, four solenoids were positioned and fixed at each corner.…”

A liquid progressive multifocal lens adjusted by the deformation of a non-uniform elastic membrane due to the variation of liquid pressure

“…After the surface treatment by the oxygen plasma, the two treated elastic membranes are placed and their edges are kept together tightly for about 24 h. Then a reliable connection without leakage can be achieved. By using an adhesive film (ARclear® Optically clear adhesive 8154, Adhesive Research, Glen Rock, PA USA), the uniform thickness membrane and the substrate can also bond together tightly [19,20].…”

Lorentz Force Actuated Tunable-Focus Liquid Lens

“…Thanks to the near-incompressibility of liquids, these lenses can utilize a variety of different actuators, including pneumatic [15,16,17,18,19], electrowetting [20,21,22,23,24], magnetic/electromagnetic [25,26], piezoelectric [27,28,29,30,31,32], electrostatic [33], dielectrophoretic [11,34], or any other actuator that can be coupled to a sealed liquid chamber to provide focus tuning. Electromagnetic actuators are particularly appealing because they can enable extremely fast response times on the order of 2–3 ms [35,36]. Electromagnetic actuators can also apply large enough forces to a system to enable relatively large deformation of the membrane that defines the lens, and these large deformations translate into a larger range of potential focal lengths of the liquid lens.…”