Fabrication of flexible microlens array film using roll-to-roll process

Abstract

Microlens arrays are a vital part of today’s optical systems, and advances in fabrication technology have broadened microlens array applications. The roll-to-roll fabrication process has an advantage in its fast and mass replication of microstructures, and it is a good fit for fabricating devices based on flexible substrates. To investigate the roll-to-roll process in the making of microlens arrays of different radii in the same process, this study designs microlens arrays with radii ranging from 55 to 240 µm and with a height of 15 µm. The material for the lens is an ultraviolet curable resin with a refractive index of 1.5. The lens pattern is first transferred to an 80-µm-thick stainless steel sheet through an etching process. The patterned sheet is then wrapped around a stainless steel roller for roll-to-roll fabrication of the microlens array film. The substrate for the microlens array is a polyethylene terephthalate film 188 µm in thickness. When operating with a substrate forward speed of 0.251 m/min (1 r/min) and imprinting pressure of 0.6 MPa, the replication rates achieved for both the radius and the height of the microlens arrays are about 97%. Single-peak filling patterns are found with the small radii lenses, while dual-peak patterns are found in lenses with bigger radii. Overall, this study demonstrates the potential of roll-to-roll in three-dimensional pattern fabrications and its application in microlens array optical film fabrication.

Roll-to-roll stack and lamination of gas diffusion layer in multilayer structured membrane electrode assembly

“…R2R system has been proved an efficient and low-cost manufacturing method in the production of solar cell, 16,17 flexible display, 18,19 and flexible electronics. 20,21 The proposed GDL continuous overlaying system adopts R2R stack and lamination technics.…”

Rapid CO2 laser processing technique for fabrication of micro-optics and micro-structures on fused silica materials

“…Micro-optics and micro-structures are widely used in optical communication, micro-opto-electro-mechanical systems, lab-on-a-chip devices sensor applications and other fields. 1–3 Also, there are many kinds of micro-optics and micro-structures, such as microfluidic channels, 4–6 micro-lens arrays, 1,7,8 optical fiber, 9,10 diffractive optics, 11 holographic structures 12 and laser-induced periodic surface structures (LIPSSs). 13 Compared with micro-optics and micro-structures made of polymers, those micro-optics and micro-structures made of glass have been widely and reliably used in harsh environments due to their stable thermal, chemical and physical properties.…”

Experimental investigation of the influence of chip interference on burr height in machining micro V-grooves on electroplated copper roll die

“…Currently, the roll-to-roll (RTR) imprinting technology is one of the most mainstream technologies which can manufacture the large-area microstructured surfaces in a high-precision, high-efficiency and lowcost way. [1][2][3][4] The roll die with microstructured surface is used to imprint the target surface and then the highprecision microstructures on target surface can be obtained with subsequent processes. Thereinto, the electroplated copper roller with microstructured surface is employed as the frequently used roll die.…”