Liquid crystal (LC) molecules are shaped so that they naturally align with each other if put in a cell to form an optically active pixel. In a display device the liquid crystal pixel is used to change the polarisation of the light passing through it and the degree of change (seen as contrast) is done through an applied voltage onto electrodes at the top and bottom of the cell. The applied voltage makes the LC molecules rotate in the cell and changes their orientation with respect to the light passing through the cell. This cell geometry limits the ways in which the light can interact with the liquid crystal molecules to a 2 dimensional plane. If we add a 3 dimensional element to the lower electrode we can change the way in which the voltage interact with the LC molecules to make a 3 dimensional optical structure. A simple example is shown on the top image on the right handside, where a thin conducting rod is added to the lower electrode to create a Gaussian electric field profile which forms a tiny microlens in the LC material. With many rods it is possible to create array of micro lenses which can have a focal length that varies with the applied voltage. Such a reconfigurable array has many uses in adaptive optical systems and 3D holographic displays.

Talking about his work Tim says "My idea is to combine two well established technologies, liquid crystals and nanotechnology to make a new hybrid device. The LCs has the ability to create a reconfigurable optical modulator (such as would be seen as 2D pixels in a liquid crystal device (LCD)) with the vertically grown multiwall carbon nanotubes (MWCNT) which act as a 3D electrode structure. In a traditional LC device (such as a display screen) the pixel electrodes are above and below the LC and allow it to be switched in a simple way. In the hybrid device the lower electrode is the MWCNT grown on silicon which sticks out from the surface into the 3rd dimension. This is also a more complex electric field profile which in turn creates a more complicated 3D refractive index profile in the LC layer. Hence we can make very complicated optical elements using a very simple device structure and an applied voltage to switch it.

An example is when the MWCNTs on the lower electrode surface are all connected and switched with the same voltage. The resulting electric field profile surrounding each MWCNT electrode is Gaussian in shape which creates a Gaussian refractive index profile in the LC layer. This looks optically like a tiny lens which is centred on each MWCNT, hence for an array of CNTs spaced 10μm apart we end up with an array of microlenses 10μm apart. By changing the voltage applied to the CNTs we can switch the micro lenses on and off and also vary their focal length. There are many applications for such a switchable microlens array such as in adaptive optical systems where the ability to self focus a lens is important or as an active diffuser in a head mounted display system.

More importantly this breakthrough changes the way in which we think about creating liquid crystal devices. It allows us to include a 3D element to the design of modulating characteristics. If we address each individual CNT with a separate voltage then we can build more complex 3D refractive index profiles similar to those you would see in a full 3D photographically recorded hologram. However the difference with the LC/CNT device is that the hologram can be changed dynamically as you would change an image on a LCD. This allows full 3D displays to be built using this sort of technology."

Articles on this research appeared in EuroPhotonics trade magazine (August 2008), in Advanced Materials and in Advanced Imaging Magazine (January 2009).

He won the third place Best Student Paper Award at the 7th IEEE International Conference on Sensors that was recently held at Lecce, Italy. His paper entitled "Laminar to Turbulent Flow Transition Measurement Using an Array of SOI CMOS MEMS Wall Shear Stress Sensors" was one of the six finalist student papers (out of sixty papers) selected by a panel of international experts. During the conference, the authors of the six finalists papers were asked to give a six minute special presentation to the selection committee, which chose the best three papers based upon the originality, quality of research work and quality of written and oral presentation of the authors. The other co-authors with Ibraheem, also from the Department, include S. Zeeshan Ali and Dr Florin Udrea from the HVM Group, and John Coull and Professor Howard P. Hodson from the Whittle Laboratory.

The IEEE Sensors conference is the most prestigious international forum for the presentation, discussion, and exchange of information in the field of sensors.

Ibraheem Haneef is currently working under the supervision of Dr Florin Udrea (Head of HVM Group) in collaboration with Professor Howard Hodson (Head of Whittle Laboratory) on SOI CMOS based MEMS flow sensors. The novel flow sensors developed by Ibraheem during his PhD research have outstanding performance compared to the conventional sensors. These sensors have potential applications in aerospace industry for wall shear stress (or skin friction drag) measurement and in automotives as mass air-flow (MAF) sensor. Due to their extremely small size, these sensors can also be used for prognosis and diagnosis of coronary artery disease. A number of companies have shown keen interest in using these novel sensors that have already been IP protected through a UK and International patent application filed with UK Patent Office.

These sensors are being commercialised by Cambridge Enterprise, whose role is to help University of Cambridge inventors, innovators and entrepreneurs make their ideas and concepts more commercially successful. For further information on the commercial applications for these sensors please contact Dr Zlatka Stoeva at Cambridge Enterprise: Zlatka.Stoeva@enterprise.cam.ac.uk

Professor Dame Ann Dowling Head of Engineering is included in the list. As the UK lead for the recent 'Silent Aircraft' initiative, Ann aimed to develop a conceptual design for an aircraft whose noise would be almost imperceptible outside the perimeter of a daytime urban airport. She is a Fellow of Sidney Sussex College.

Also from the Department of Engineering is Professor Mark Welland Director of The Nanoscience Centre. His research encompasses a number of aspects of nanotechnology ranging from sensors for medical applications to understanding and controlling the properties of nanoscale structures and devices. He is also Chief Scientific Adviser at the Ministry of Defence.

The list includes the following Cambridge academics from other Departments:

Stephen Hawking is the Director of Research at the Department of Applied Mathematics and Theoretical Physics, Emeritus Lucasian Professor of Mathematics at the University as well as a Fellow of Gonville and Caius College. Hawking is best known for his pioneering research into black holes, thermodynamics and unifying Einstein's general relativity theory with quantum theory, as well as his book A Brief History of Time.

Sir Richard Friend, Cavendish Professor of Physics and Fellow of St John's College, has revolutionised our understanding of carbon-based semiconductors. His research helps to develop flat panel displays, and flexible screens that can be rolled up and transported.

David Mackay is Professor of Natural Philosophy at the Cavendish. He is the creator of Dasher, a machine-learning system that allows users to navigate using any muscular movement, their breath or gaze, and write using a continually unfurling alphabetical display. He is also currently Chief Scientific Advisor at the Department of Energy and Climate Change.

Sir David Baulcombe holds the Regius Professorship of Botany at the University of Cambridge. Sir David discovered how small molecules of ribonucleic acid (RNA) govern gene activity through a process known as RNA silencing. Professor Baulcombe's research has unravelled how this mechanism is important in gene regulation and in disease resistance. He is a Fellow of Trinity College.

Sir Greg Winter is a Fellow of Trinity College and Deputy Director of the MRC's Centre for Protein Engineering. He is known for his pioneering work on therapeutic monoclonal antibodies.

Professor Sir Leszek Borysiewicz is the new Vice-Chancellor of the University of Cambridge. He was Chief Executive of the UK's Medical Research Council from 2007 to last month, and from 2001 to 2007 was at Imperial College London, where he served as Principal of the Faculty of Medicine and later as Deputy Rector.

Professor Steve Ley is BP Professor of Organic Chemistry at the Department of Chemistry and a Fellow of Trinity College. His research focuses on developing new synthesis methods and applying them to the construction of biologically important molecules.

George Efstathiou is Professor of Astrophysics and Director of the Kavli Institute of Cosmology. Professor Efstathiou and his team provided some of the first evidence that dark energy exists. He is a Fellow of King's College.

Steve O'Rahilly is Professor of Clinical Biochemistry and Medicine and Co-Director of the Institute of Metabolic Science. His research focuses on the links between genetics and obesity.

Shankar Balasubramanian, Herchel Smith Professor of Medicinal Chemistry at the Department of Chemistry, developed (along with Professor David Klenerman) low-cost, high throughput sequencing that enables researchers to undertake large-scale projects. In 1998 they founded the spin-out company Solexa (which was later purchased by Illumina) to commercialise their inventions.