Project ideas

We are looking for industrial and/or academic partners who would like to explore project ideas with us. Examples of ideas in our pipeline are listed below.

If you would like to discuss your own or some of the showcased ideas please contact us: metamaterials@exeter.ac.uk.

Optoelectronic devices working in the infrared have a host of important applications in the areas such as communications, security, defense, imaging, medicine etc. Most current infrared devices are however essentially passive - their operating characteristics are fixed by their structure and design. But there is a growing interest in active, i.e. tuneable or reconfigurable, infrared devices and systems, where the operating characteristics can be changed ‘on the fly’ to respond to changing needs. In this project we will develop such active devices by combining the dielectric (optical material property) control offered by switchable chalcogenide phase-change materials with novel optical metasurface concepts. Target applications include LIDAR, multispectral imaging and holographic displays.

Acoustic Metamaterials (AM) are regarded as a potential solution as sound absorbers in the previously unattainable low frequency band (<1 kHz). The vast majority of AM consist of arrays of local resonators, mainly membrane based, however their performance is often narrow band.  Our ambition is to push the boundary of AM to address technological challenges of low frequency broadband sound absorption in practical environments.   We will draw on our expertise in widening the bandwidth of electromagnetic devices, while also applying our previous work on tuneable vibrational energy harvesters, such as magetically induced non linearity, and closed-loop tracking systems, to provide absorbption of ambient acoustic frequencies.

Objectives of this project are to:

  1. design low power mechanisms to tune the resonant frequency for membrane-based AM below 1 kHz.
  2. optimise performance of magnetically induced nonlinear AM below 1 kHz.
  3. develop an autonomous closed-loop frequency tracking system for frequency tuneable AM.
  4. demonstrate sound absorption using the broadband AM.

The Nano Engineering Science and Technology (NEST) group currently researches within a portfolio of awards exceeding £13m. The PI (Zhu) is currently leading development of underwater energy harvester funded by Innovate UK (103380) and has previously led research into mechanical and electrical methods of tuning the resonant frequency of vibration energy harvesters together with control algorithms.

Existing solutions are either theoretical or have obvious weaknesses such as limited broadband, high power consumption and large dimensions

Quantum thermodynamics is a new research field, where thermodynamics is studied in the small-system size limit where fluctuations become non-negligible, weak coupling between system and environment cannot be assumed, and a fully quantum mechanical description may be needed. This project is concerned with the application of theoretical tools from the fields of quantum thermodynamics and open quantum systems to the problem of modelling the dynamics, the equilibrium state, and the timescale of equilibration, of a collection of interacting spins that are strongly coupled to their environment. The aim of this project is to find analytical equations that describe the spin dynamics when they are driven by a changing magnetic field and exposed to a heated environment (with potentially multiple temperatures). These will then be used to quantify the importance of quantum mechanical and strong coupling effects in the magnetization dynamics and in the long-time steady state of the spins.

Waves propagating in quasicrystals are at a curious point where neither Bloch’s theorem (applicable to periodic media), nor the diffusion approximation (applicable to random media) are appropriate. While quasicrystals can be constructed from a deterministic rule, they do not exhibit the translational invariance that allows propagation to be understood in terms of a single unit cell. However, it has been known for some time that diffraction from photonic quasicrystals exhibits similar sharp peaks as are observed for true periodic crystals, due to the presence of long range order.  This project explores the propagation of electromagnetic waves on the surface of 2D quasicrystals. Such lattices (e.g. those generated using the Fibonacci sequence in particular) have an interesting link to topology via Chern numbers, and fractals.  Although little experimental work has been done to explore these aperiodic structures, our fabrication and characterisation techniques for exploration in the microwave domain naturally lend themselves to this project, and to accompany this experimental strand, there will be a challenging programme of numerical and analytical modelling work for the student to undertake.

  • Please contact Prof Roy Sambles, Dr Simon Horsley, and Prof Alalstair Hibbins via metamaterials@exeter.ac.uk for more information.

This project will quantitate the physical interactions between individual bacteria such as Escherichia coli and Pseudomonas aeruginosa with commonly employed antimicrobials such as antibiotics or phages. This will be done via a novel approach for single-cell analysis relying on a combination of microfluidics, microscopy and mathematical modelling. This novel knowledge will inform on how cell-to-cell differences within a bacterial population impact antimicrobial resistance that is a major societal problem. Therefore, this project will be paramount for repurposing existing antimicrobials as well as rationalising the design of the next generation of therapeutics against infections caused by gram-negative pathogens.

This project aims to optimise graphene-based conductive inks and fabricate coils on textiles for wearable wireless power transfer (WPT) applications.

There is increasing demand for embedding electronics into fabrics for wearable applications. Most wearable electronic devices are battery-powered and require regular recharging. Nowadays, more and more wearable electronic devices are rechargeable using inductive WPT techniques. It operates based on the near-field electromagnetic coupling of coils. This concept can be applied to body-worn textiles by integrating a transmitter coil into upholstery, and a receiver coil into garments. This is of particular interests in healthcare applications, including the growing market of remote healthcare, as wearable medical devices can be charged whenever the patients rest without any external interference.

In this project, conductive polymer-based or graphene-only inks will be developed for improved conductivity and durability, and for easy and textile industry-compatible deposition methods. Coils will be designed and fabricated directly onto textiles. Different types of graphene (liquid-exfoliation and redox) will be employed for the preparation of conductive inks that can be easily applied onto textiles and flexible substrates. Different solvents, polymeric matrices, and processing methods (spray-coating, optical lithography, etc.) will be investigated and optimised.

Objectives:

  1. develop graphene-based conductive inks
  2. optimise coil design for textile applications
  3. fabricate optimised coils on textiles using solution-processing methods
  4. demonstrate wireless power transfer capability using fabricated coils

Please contact Dr Dibin Zhu and Dr Ana Neves via metamaterials@exeter.ac.uk for more information.

This project aims to optimise sorting of biological cells according to their mechanical properties by utilising novel Deterministic Lateral Displacement (DLD) devices.

It is now well established that various diseases lead to alteration in the physical properties of the cell plasma membrane such as membrane elasticity, viscosity and electrostatics. This effect, often due to disease-associated factors such as elevated levels of oxidative stress, in turn could compromise a number of biological functions hosted by the plasma membrane.  Sorting of cells according to their physical properties is therefore an important step in understanding the effects of disease on membrane properties and cell function. In this project, we shall  focus on novel strategies for cell sorting based on their viscoelastic properties.  Novel DLD prototypes will be based on structured microfluidic devices with carefully controlled geometries, and underpinned by numerical simulations. The concept will be validated using in vitro experiments on human red blood cells, modified to produce cell subpopulations of different viscoelastic properties (membrane bending and shear moduli, membrane and cytoplasmic viscosity) and geometry (volume-to-area ration), all of which are important in setting cell deformability. Independent control of the membrane mechanical properties will be ensured by using additional single-cell techniques such as thermal fluctuation spectroscopy, micropipette aspiration and fluorescence-based methods. Later stages of the project will focus on designing and implementing adaptive microfluidic devices capable of optimising cell sorting depending on particular cell properties in the subpopulations. This is an exciting interdisciplinary project on the boundary between physics, biology and metamaterials.   

This project explores the role of metasurfaces loaded with magnetic materials in manipulating electromagnetic waves in the RF and microwave bands. In particular, we will identify metasurface designs that allow for instant switching of the operation of devices, such as steering beams or tuning the frequency of filters, absorbers or sources.  The research will be undertaken using a full electromagnetic wave solver that takes into account both electric and dynamic magnetic response of materials.  Developed in house, and unavailable commercially, our state of the art software solves Maxwell and Landau-Lifshits-Gilbert equations simultaneously. It can be utilised to explore the use of magnetisation dynamics of highly structured magnetic configurations (e.g. vortices, domain walls).  Although the project primarily aims at numerical modelling, it is anticipated that some (successful) models will be verified experimentally.