Advanced Functional Materials

This proposal is a Platform Grant renewal. Our previous grant allowed us to develop the key characterisation facilities and enabled us to understand fully the materials that were the study of the grant. These materials were low loss microwave dielectrics, ferroelectric materials and thin films of these materials.
The Platform renewal will build upon some remarkable discoveries that the team, including the key PDRAs, has made over the last 4 years and centre around functional materials for devices operating from microwave to millimetre wave or from MHz to THz. First it is important to explain the Materials Science progress that forms the underpinning technologies that will enable us to use the Platform grant to build new devices. At the heart of microwave devices are resonators that require low dielectric loss or very high Q factor and the target is to aim for very high Q dielectrics. Our previous Platform grant and indeed prior support from EPSRC allowed us to discover very low loss, high Q materials. This culminated in two significant discoveries.

1 First we were able to use low loss resonators as sensors for liquid sensing
2 Second, we demonstrated that by using a very high Q resonator we could achieve maser action at room temperature
and in Earth's field - published in Nature 2012.
This platform grant will enable us to build upon these discoveries.
1) Advanced Characterisation: In the first theme the aim will be to carry out a series of qualifying experiments to determine the best possible conditions and materials for sensing over the wide range of frequencies available to us (Hz to THz)
2) Microwave and mm wave sensors: The third theme takes the science to application. We will use the resonators for analysis of ions, biomolecules, proteins and cells. The sensitivity of the resonators allows nanolitre quantities to be analyzed very rapidly for possible cancer cell detection in blood and bacteria in water.
3) "UMPF" and "HEP" Cavities: In the second theme we aim to make UMPF (Ultrahigh Magnetic Purcell Factor) and "HEP" (High Electric Purcell) cavities. These are small resonant cavities with a very high Q given the very small mode volume and success here will enable us to improve electron paramagnetic sensing dramatically and enable single cell detection.
Success in these new themes for the Platform would represent a remarkable step-change in technology.

The key impacts of this Platform will be focus the team's efforts towards devices and these new directions represent significant added value. We intend exploiting new discoveries made by the team, notably - biosensing (Klein, Alford et al) and the use of the ultra high magnetic Purcell Factor (UMPF) cavities and High Electric Purcell (HEP) cavities in devices. With the characterisation for physical and physico/chemical properties already in place (SIMS-LEIS, HRTEM, XRD, XPS) we will take advantage of our new outstanding capability in rf/microwave to THz vector network analysers to probe the frequency dependent properties of our materials.

With our Project partners, Link Microtek, Bruker and Ericsson we will target the following:

1) Advanced Characterisation - particularly focussing on characterising materials for high frequency (to THz) sensors. Development of advanced techniques at MHz to THz for sensing. This will involve the use of recently acquired capital equipment recently purchased capable of vector network analysis to 0.5THz.
2) Microwave and mm wave sensors. Taking the specifications derived from the advanced characterisation in (1) and fabricating proof of principle devices for biosensing. The challenges of microwave-to-terahertz biosensors are due to strong water absorption from the low Gigahertz range towards a few terahertz: This feature enables to measure the complex dielectric function of water and its modifications due to proteins and other biomolecules within cells, tissue or any bio-liquid sample with high precision in real time on volumes down to a single cell size.
3) Ultrahigh-Magnetic-Purcell-Factor ("UMPF") Cavities - for use in electron paragmagnetic resonance sensors at microwave (GHz)
This would impact upon instrumentation development and industries involved in healthcare. It would of course, impact upon NHS costs. "HEP" cavities (High Electric Purcell) have the potential to analyse picolitre fluid quantities and hence achieve single cell detection.

This research will impact upon
Society - the ability to develop new techniques in biosensing and untra sensitive EPR will have a major impact on society's health and well-being by bringing extraordinary sensitivity with new techniques.

Economy - These new developments are ripe for commercialisation and we will process inventions through Imperial Innovations, our technology transfer arm. We already have agreements with the industrial partners regarding exploitation of IP.

People and Knowledge - Our track record of increasing the knowledge base in both academia and industry is excellent and we will continue to ensure that this track record of success continues. Additionally, we have excellent systems in place for outreach. The Imperial College Festival celebrating the Science and Engineering at the College takes place each year and received 12,000 visitors in 2014. We will ensure that the outputs from our Platform receives full coverage.