Microlens array fabrication on WC mold using EDM milling with in situ electrode trimming

Zhou, Tianfeng; Ma, Fubin; Ruan, Benshuai; Zhou, Jia; Liew, Payjun; Wang, Xibin

doi:10.1007/s00170-019-03731-0

Cited by 7 publications

(2 citation statements)

References 21 publications

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“…Microlenses are of technological importance for a range of applications, such as photovoltaics, solar concentrators, imaging, sensing, beam‐steering, and optical interconnects. [ 1–11 ] In recent years inkjet printing is rapidly becoming an attractive method for fabricating microlenses [ 12 ] as it enables the scalable deposition of multiple materials on a variety of substrates with high precision and is an economical process for fabricating microlens arrays over large areas. For example, with this method droplets can be ejected rapidly so that it is possible to build up large arrays of 1000s of microlenses in a matter of seconds.…”

Section: Figurementioning

confidence: 99%

Electrically Tunable Printed Bifocal Liquid Crystal Microlens Arrays

Kamal

Lin

Elston

et al. 2020

Adv Materials Inter

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In this communication, the fabrication of electrically tunable bifocal liquid crystal (LC) microlenses using drop‐on‐demand inkjet printing is demonstrated. By treating the glass substrate with a homeotropic alignment layer, the printed droplets are found to form plano‐convex lenses with focal lengths in the range of 220–463 µm, depending upon the number of droplets deposited at each location on the substrate. The precision of the process allows for the microlenses to be deposited in between in‐plane indium tin oxide electrodes. In the presence of a high amplitude electric field, the director within the LC droplets is observed to align with the direction of the applied field, but without any accompanying distortion in the droplet profile. However, these changes in the LC director alignment are found to result in a bifocal behavior rather than a continuous change in the focal length. It is also found that there exists a range of voltages for which two focal planes are observed.

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Section: Figurementioning

confidence: 99%

Electrically Tunable Printed Bifocal Liquid Crystal Microlens Arrays

Kamal

Lin

Elston

et al. 2020

Adv Materials Inter

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“…Zhou et al [22] used micro-milling technology to process the micro-groove array structure and thermo-forming technology to replicate high-precision polymer micro-arch array lenses. Zhang et al [23] used induction heating to achieve effective hot embossing of polymer array structures on silicon-based molds.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Optical Characterization of Polymeric Aspherical Microlens Array Using Hot Embossing Technology

Gong

2021

Applied Sciences

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Hot embossing has been widely used in fabricating microlens arrays because of its low cost, high efficiency, and high quality. The process parameters such as molding temperature, molding pressure, and holding temperature affect the microlens array’s replication quality. This work selected the stainless steel S136H tool steel as the mold material to process an aspheric microlens array structure through ultra-precision milling. Polymethyl methacrylate (PMMA) microlens arrays with different surface replication were prepared by controlling the molding temperature, molding pressure, and holding temperature. By analyzing the surface quality, contour replication, and optical imaging of hot-embossed samples, the optimal molding temperature of PMMA for optimal replication of aspheric lens arrays was determined as 130 °C. Besides, the internal elastic recovery of PMMA affected the dimensional accuracy and optical performance of the lens. The results showed that, at the molding pressure of 400 N and the holding temperature of 60 °C, the surface defects were eliminated, and the aspheric lens array had perfect replication with a profile deviation of only 4 μm. The aspheric microlens array with good quality was eventually achieved by these optimal process parameters, which provides a foundation for producing aspheric microlens arrays in a low-cost and high-efficiency way.

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