Precision Printing of Liquid Crystals & Polymers
Inkjet Printing of Liquid Crystals & Polymers
Our research, which is in collaboration with the Fluid Dynamics group led by Professor Alfonso Castrejon-Pita, revolves around the printing of liquid crystals (LC) and polymer composites for the fabrication of next-generation thin-film optical elements and devices. Drop-on-Demand (DoD) inkjet printing is a non-contact technique that allows for the precise deposition of pico-litre volume droplets of ink to create micron-sized objects. The capabilities of DoD printing go well beyond the contact-based printing methods, such as gravure offset and screen printing, as it provides greater flexibility in terms of the variety of materials that can be deposited using a layer-by-layer approach on a range of substrates and surfaces including flexible substrates.
Figure 6. An array of printed LC microlenses.
Figure 7. Printed nematic LC droplet.
LCs are a class of functional fluid that possess unique electro-optical properties, providing enormous opportunities for the development of active and passive optical components. Combining LCs and DoD inkjet printing opens up new pathways in the fabrication of functional thin-film optical elements and devices (Figure 6). Chemical control of the printing substrate as well as the precise deposition of the LC based inks can lead to the engineering of structures and configurations that exhibit special optical properties (Figure 7). Our work includes a broad and in-depth investigation of the printing conditions that are required to deposit a range of LC ink formulations in a controlled and precise manner without the formation of satellite droplets or jet break-up. We are also study the effect of substrates on the printed drop formation as well as possible thin-film optical elements that can be fabricated using this additive manufacturing technique.