Controllable liquid colour-changing lenses with microfluidic channels for vision protection, camouflage and optical filtering based on soft lithography fabrication

Abstract

In this work, liquid colour-changing lenses for vision protection, camouflage and optical filtering are developed by circulating colour liquids through microfluidic channels on the lenses manually. Soft lithography technology is applied to fabricate the silicone liquid colour-changing layers with microfluidic channels on the lenses instead of mechanical machining. To increase the hardness and abrasion resistance of the silicone colour-changing layers on the lenses, proper fabrication parameters such as 6:1 (mass ration) mixing proportion and 100 °C curing temperature for 2 h are approved for better soft lithography process of the lenses. Meanwhile, a new surface treatment for the irreversible bonding of silicone colour-changing layer with optical resin (CR39) substrate lens by using 5 % (volume ratio) 3-Aminopropyltriethoxysilane solution is proposed. Vision protection, camouflage and optical filtering functions of the lenses are investigated with different designs of the channels and multi-layer structures. Each application can not only well achieve their functional demands, but also shows the advantages of functional flexibility, rapid prototyping and good controllability compared with traditional ways. Besides optometry, some other designs and applications of the lenses are proposed for potential utility in the future.

Electroluminescent Pressure-Sensing Displays

“…It should be also noted that the EL sensitivity we obtained was orders of magnitude higher than the light emission sensitivity values of state-of-the art results based on triboelectrification EL 18 and capacitive change. 31 Interestingly, the sensitivity from capacitive change is highest at low pressures, whereas the sensitivity from the EL change is best at high pressures.…”

“…Besides quantitative and precise detection of pressure, which is among the most important functions in numerous applications including smart windows, displays, security systems, mobile phones, and prospective electronic skins (e-skins), − direct visualization of the pressure source while sensing it can further extend the usefulness of a sensor by offering novel functions such as shape and position recognition of a pressurizing object and dynamic motion monitoring of an object on a sensor. − This approach, commonly studied in the area of interactive displays, has been extensively developed. Tunable-coloration/light emission have been successfully demonstrated by combining optical elements with pressure sensors mainly based on the pressure-dependent change in either electrical resistance − or capacitance, − allowing the visualization of pressure; the examples include organic light-emitting diodes, electroluminescence, and − electrochromic − and triboelectrification devices. , Considering that the various coloration display elements based on absorbance and reflective modes in general suffer from rather low brightness, slow response time, and low light efficiency, the interactive electroluminescent (EL) displays are promising due to their benefits of ultrathin and high color contrast and efficiency.…”

Research on liquid flow behavior in deformed microfluidic channels made of PDMS material

“…PDMS optical membranes with microfluidic channel structures were fabricated by soft lithography [17][18][19], which replaced conventional mechanical machining. Some basic applications of the microfluidic lens were realized, including vision protection, camouflage and optical filtering [20]. However, no in-depth analysis of the liquid flow behavior in these systems has been carried out so far, resulting in an insufficiently optimized structures and poor performances of the systems.…”

A Camouflaged Film Imitating the Chameleon Skin with Color-Changing Microfluidic Systems Based on the Color Information Identification of Background

“…Those glasses realized human eyesight protection and filtering of lights with different wavelengths. The structures and principles were simple, manufacturing was convenient and fast, and they could realize fast switching basing on users' requirements [28,29]. Since liquid inside the whole micro-channel has a small volume and lightweight, utilizing microfluidic techniques to achieve color-changing camouflage became a good choice for stable camouflage and maneuvering camouflage both.…”