par Parry, Ellis;Bolis, Serena 
;Castrejón-Pita, Alfonso;Elston, Steve J.;Morris, Steve M.
Référence European Conference on Liquid Crystals 2017 (25-30 June 2017: Moscow (Russia))
Publication Non publié, 2017-06-25
;Castrejón-Pita, Alfonso;Elston, Steve J.;Morris, Steve M.Référence European Conference on Liquid Crystals 2017 (25-30 June 2017: Moscow (Russia))
Publication Non publié, 2017-06-25
Communication à un colloque
| Résumé : | Drop-on-demand (DoD) inkjet printing is an efficient process for controlling the exact position, size and speed of a droplet of fluid. Traditional DoD inkjet printing has been firmly established in the fields of graphical printing, additive manufacturing and printed electronic. Due to its excellent efficiency and flexibility, along with the ability to print ever more viscous and complex fluids, ink-jet printing is currently being looked at as an attractive alternative fabrication step in a range of production processes [1]. One innovative application of inkjet printing is the deposition of liquid crystals (LCs). Modern LC devices typically rely on the fluid being sandwiched between glass substrates. Inkjet printing LCs offers unique benefits such as quickly producing large arrays, confining the LC in unique geometries, printing onto a variety of substrates and combining the LC fluid with different functional inks at the substrate surface. We present a bespoke experimental inkjet printing system, capable of depositing a variety of complex fluids and interrogating the complete printing process. In particular, we demonstrate how DoD inkjet printing can be used to form tuneable liquid crystal micro-lens arrays. Microlenses are fundamental optical components that are used extensively in light collection, imaging and sensing applications. Current methods to achieve tuneable microlenses include; liquid filled elastic lenses, gradient refraction index and LC lenses. However, these manufacturing methods require multiple and complex fabrication steps, with the resulting device often hindered by mechanical parts, geometric restrictions and polarisation dependent focussing. This ultimately increases the cost and complexity of devices. We demonstrate DoD printing of tunable LC microlens arrays and show that by exploiting the substrate properties, both the curvature and director profile within the lens can be controlled. Finally, we present thermal tuning of the focal length of high-quality, high-precision printed LC lenses. References:[1] J.R. Castrejon-Pita et al., Future, Opportunities and Challenges of Inkjet Technologies. Atomization and Sprays, 23 (6), pp. 571-595 (2013). |
