Topological control of soft matter using novel nano-replication manufacturing

Lead Research Organisation: University of Leeds
Department Name: Physics and Astronomy

Abstract

Liquid crystals (LC) are familiar to us all, through their use in the LC Displays (LCD) used in our phones and TVs. These self-assembling organic materials are used increasingly in a wide range of other applications, from smart windows to telecommunications, from Virtual Reality headsets to sensors. Over the past decade, there has been an explosion of interest in using topological defects in liquid crystals, and their use to aid the self-assembly of colloidal particles added to the liquid crystal or micro-droplets of liquid crystal in dispersions. The applicant co-invented the Zenithal Bistable Display (ZBD), an LCD that stores the image by creation of topological defects at a surface-grating layer, thereby operating with ultra-low power. He founded the spin-out Displaydata to commercialise the technology and that company has grown to become a world leading supplier of graphic shelf-edge labels to the retail sector. With any electro-optic device, such as a display, it is important that the electric field is applied uniformly and without unnecessary losses. Although nano-imprint lithography is now a well-established technique, it is not ideally suited to electro-optic devices for these reasons. Previously, the investigator developed nano-embossing and selective adhesion methods to add gratings onto the inner surfaces of the ZBD LCD both uniformly and efficiently, transferring them to manufacturing production lines in the Far East.
On moving to Leeds University with an EPSRC Manufacturing Fellowship designed to attract industrialists into academia, the applicant has set up a prototyping facility that includes these techniques, and has extended the processes to allow more complex surface structures with new functionalities to be made. These include making simple lenses using liquid crystals that operate with near 100% efficiency and without polarisers. We are all familiar with how dull a reflective watch LCD seems because more than half of the light is absorbed by polarisers either side. Polarisation dependence hinders the use of liquid crystals in many applications, but with the nano-embossing method there is a great potential to solve that problem. This project focusses on extending the physics and technology for these ideas, bringing these inventions to a level where the commercialisation process may begin, and cultivating them for other optical devices such as high efficiency switchable computer generated holograms or camera lenses, or creating bistable switchable lenses that operate with minimal power.
As well as being an entrepreneurial physicist, the applicant has a wealth of new ideas that could be accelerated towards making practical devices, from fast electro-optic shutters, to low voltage smart windows using liquid crystal shells, and novel sensors and displays based on multi-faced Janus-particles that flip under an electric field. During the course of the Fellowship so far, he has applied his manufacturing and device expertise to creating switchable contact lenses for the correction of presbyopia, the poor eyesight that everyone over fifty suffers from. This led to his second spin-out company, Dynamic Vision Systems Ltd. With such a high success rate of making new inventions that are backed by ground-breaking research, the funding of this proposal has a high potential to lead to real wealth and job creation for the future, as well as generating new science and technology.

Planned Impact

The project has the direct objective to take an invention from early demonstration through to the point at which industrial and commercial interest can be garnered, whether that is through license or spinout. Given the early stage of the idea, that target is ambitious, but the impact on wealth creation and jobs could be high. In particular, the extension of new manufacturing methods based around nano-embossing that were made in the current Fellowship to aligned and birefringent materials has the potential for wider use in the field of optics and electrooptic devices, from enabling embossed geometrical optics (such as Panchatranam lenses) to new device modes. One aim in particular would be to create a liquid crystal lens that has sufficient clarity and operating performance, that it could be used in mobile phone cameras.

The design of novel LC systems has long been a strength of the UK liquid crystal community and has had a significant impact on both international academic research and on the displays industry, generating substantial royalties to the UK Government and commercial activities of multiple industrial groups in the UK (including Merck, Sharp, Microsoft, Proctor and Gamble, Forth-dimension, Flexenable, Displaydata, etc). There is significant interest in non-display applications of LCs, as wide ranging as spatial light modulators for telecommunications, wave-front correction, smart windows, controllable lighting and environment, and biological and chemical sensors. In the field of displays too, there remain the challenges of producing high reflectance colour and holographic 3D displays. Liquid crystals remain strong contenders as solutions to these challenges and the longer-term work of the proposal will make an impact. This has been recognised by Merck, as the world-leading supplier of the materials that go into such devices, Merck is a potential beneficiary of any increased sales of liquid crystals, who give strong support to this proposal.

The company recently co-founded by the applicant, Dynamic Vision Systems, operates in the healthcare sector, combining liquid crystals and printed electronics to manufacture switchable contact lenses. This aims to relieve millions of presbyopia sufferers in the UK alone, and of course has the potential to address this important global problem. This company and could benefit directly if the polarisation independent operation of liquid crystals can be extended to contact lenses. This will help maintain that world lead for the UK in the application of liquid crystals beyond displays. Some of the inventions being tackled in this proposal will directly impact that capability.

The EPSRC have recognised that self-assembly, photonic materials and soft matter are areas of strength for the UK and have labelled soft matter as a topic meriting increased funding. This proposal offers to help keep the UK position at the forefront of device applications using these functional materials. In addition to significant academic impact, the work will lead directly to new patents and IP, including (but not restricted to) adaptive optics, spatial light modulators, fast electro-optic shutters and beam steering. It has a strong potential for industrial routes to market, through existing industrial contacts, the applicant's proven track record of taking novel science to commercial application and his explicit desire to create a third spin-out company resulting from the proposed work, with its concomitant wealth and job creation in the North East of England.

Lastly, the project gives a unique opportunity for exposure of interdisciplinary PDRAs and PGR to training from an academic with many years of award winning science working within industry, an academic that combines invention, innovation and entrepreneurism. Already, the impact on students, and the public through outreach lectures, has been high. Extending this fellowship for the applicant will help consolidate and accelerate that impact.