Self-positioning microlens arrays prepared using ink-jet printing

Inkjet-printed microlens arrays (MLAs) were fabricated using hydrophilic confinement by UV/ozone treatment. The MLAs were made from negative photoresist SU-8 (n = 1.63 at 530 nm). A film of 10 µm thick SU-8 shadow mask was used to define UV/ozone-treated hydrophilic zones on an SU-8 photoresist base layer. An inkjet print head was used to jet SU-8 photoresist drops onto these zones. After UV-curing, MLAs with diameters of 150, 200, 400, 800 and 1000 µm were successfully fabricated. Contact angles of MLAs increased from 22° (on MLAs fabricated using an SU-8 photoresist base layer without any surface treatment) to 45.5°, 47.7°, 52.4°, 51.3° and 54.2°, for 150, 200, 400, 800 and 1000 µm lens diameters, respectively. Using hydrophilic confinement, MLAs with a wide range of contact angles can be fabricated with diameters from 150 µm to 1 mm. This method provides a simple, cost-effective fabrication process without need for etch-transfer.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fabrication of inkjet-printed SU-8 photoresist microlenses using hydrophilic confinement

Chen

2013

“…There are three main types of manufacturing methods, i.e. direct subtractive machining [6][7][8][9][10][11][12][13][14][15], molding [16][17][18][19], and additive manufacturing [20][21][22][23][24][25][26][27][28][29][30]. Direct subtractive machining, such as diamond turning, can fabricate micro lenses with a good surface finish and high accuracy.…”

Section: Introductionmentioning

confidence: 99%

Numerical and experimental study on multiphase printing of polymeric biconvex micro lenses

Sun¹,

Falahati²,

2018

Polymeric micro lenses have been popularly used in optical systems in recent decades due to the advantages of being lightweight and low-cost compared to traditional glass lenses. The multiphase printing method is a novel polymeric micro lens manufacturing method. It has the advantage of low-cost and high accuracy. To precisely control the fabrication parameters, it is important to study the influence of forming conditions on lens shape. This work developed and validated a numerical model that utilizes the Young–Laplace equation, Navier–Stokes equation, forces balance, and mass conservation to calculate the profile of the printed polymeric micro lens and to study the effects of different manufacturing parameters. Experimental validation showed that the numerical model can achieve accurate lens geometry by knowing the printing conditions. This numerical method will significantly simplify the manufacturing process of polymeric lenses, and shows the promising potential for the multiphase printing method.

“…Ink-jet printing has been used to directly print micro lenses and micro lens arrays on solid substrates [22][23][24]. Compared to other processes, the printing method can generate microto meso-scale monomer droplets which are deposited on the solid substrates followed by ultraviolet (UV) induced polymerisation to form micro lenses or lens arrays.…”

Section: Introductionmentioning

confidence: 99%

Manufacturing polymeric micro lenses and self-organised micro lens arrays by using microfluidic dispensers

Sun

Chang

2015

Micro lenses and micro lens arrays have been widely used in numerous areas. In recent years, direct deposition of micro lenses and micro lens arrays by using drop-on-demand dispensers has been studied. However, the traditional drop-on-demand methods have issues such as expensive facilities and appropriateness for low viscosity materials. In this paper, a novel droplet-based method for fabricating polymeric micro lenses and lens arrays is presented. This method utilises microfluidic devices as dispensers to generate micro- to meso-scale droplets, and uses interfacial forces to control the lens profiles. This new method can create lenses with aperture sizes from 130 μm to 2000 μm for both low and high viscosity materials. It is also capable of fabricating self-organised lens arrays with high fill factors. This technology can simplify the manufacturing process and lower the manufacturing costs of micro lenses and lens arrays.