Jess Brown at Acoustofluidics Forum

Jess presents her research

On 16th and 17th October, third year PGR Jess Brown attended Acoustofluidics Forum. She reports on her experience of the event:

 

This 2-day meeting of the Acoustofluidics Special Interest Group in the UK Fluidic Network took place at Cardiff University, hosted by Dr Chris Yang and his research group (MUSL) – this is the 9th SIG meeting since 2017, and they have been held all over the UK and further afield.
I attended with Caroline Pouya (a post-doc in my research group), and we both gave talks about our current research, discussing how it’s related to Acoustofluidics. This was the first presentation I’ve given outside the CDT, so it was a big confidence boost for me to get some external validation of my work! The other attendees had interesting questions for me to consider, and I also found some potential collaborations.
Since my research is only tenuously associated with acoustofluidics, I found learning about something slightly different a welcome and stimulating change of scene – talks about engineering and medical applications particularly stood out for me, which explored how sound can be used to sense damage in aircraft components and monitor heart function, or filter bacteria from milk and manipulate cancer cells for disease diagnosis. I also appreciated the networking sessions, meeting other PhD students and big names in the field, and sharing ideas and experiences.
Overall it was a very enjoyable event, and I’m keen to attend another soon! Back to my own research in the meantime…

Joseph Beadle submits his thesis!

Joseph Beadle with his thesis

Congratulations to CDT PGR Joseph Beadle, who submitted his thesis last week.

Joseph was supervised by Prof. J. R. Sambles and Prof. A.P. Hibbins, and his PhD project was entitled: ‘An exploration of acoustic metasurfaces’. The aim was to experimentally explore the effect that structuring surfaces had on the near-field acoustic surface waves. The project involved both airborne and underwater acoustics. He published two papers whilst at Exeter: ‘The acoustic phase resonances and surface waves supported by a compound rigid grating’ & ‘Broadband, slow sound on a glide-symmetric meander-channel surface’.

During this time he presented at international conferences such as: ASP DFD (American physics society – division of fluid dynamics) in Denver, USA (2017), and  Underwater Acoustics Conference and Exhibition, Hersonissou, Greece (2019). Joseph has been working as a member of TEAM-A based in QinetiQ, where he is expanding on his PhD work and investigating novel underwater metamaterials for the absorption and manipulation of acoustic energy.

New Publication: Controlling collective rotational patterns of magnetic rotors

Josh Hamilton

Congratulations to CDT alumnus Dr.Joshua Hamilton,  whose paper Controlling collective rotational patterns of magnetic rotors has recently been published in Nature Communications. Josh works as a postdoctoral research fellow in TEAM-A  at University of Exeter.

A summary of the paper is below:

Combining experiments, simulations, and theoretical arguments Josh Hamilton and his collaborator Daiki Matsunaga have investigated the collective motion of arrays of magnetic rotors. The surprising complex dynamics was shown to generate a fluid flow at a low Reynolds number. There creating a possibility for a method of mixing and/or pumping fluids on the micrometre scale. Depending on the combinations of the relative strengths of the external magnetic field and the dipolar interactions between the rotors, a range of collective motions was achieved. Two examples of the collective motions shown were known as the “stripe-swinging” and the “quarter-rotational” patterns.

In its simplest form, the stripe-swinging pattern occurs when the dipolar interaction between the rotors dominates over the external magnetic field. The dynamics can be understood by regarding the pattern as adding small perturbation to the rotors base condition. In their resting position, the rotors create a two-in, two-out pattern (known as a spin-ice structure). The two-in, two-out pattern intrinsically has the characteristics of a stripe. Therefore, if a small external magnetic field were applied, the rotors would form a stripe pattern and swing together back-and-forth.

The quarter-rotational pattern occurs when the interaction between the external magnetic field and the rotors is stronger than the dipolar interaction. In this mode, the rotors undergo full rotations with different quadrants of the arrays of the array turning in different directions, either clockwise or counter-clockwise. The collective rotation of the rotors was shown to be used to mix or pump fluid.

Summer Student Projects 2019

This summer, three of our then-third year PGRs (Pablo Martinez Pancorbo, Ned Taylor and Elizabeth Martin) were awarded summer student bursaries, covering a small stipend and project fees to allow them to host an undergraduate student for 10 weeks to complete a summer research project.

In a competitive process, the PGRs had to put forward project proposals, which were then reviewed by members of our Management Board and awards were granted. Once the call out had been made to undergraduates, the PGRs reviewed applications and decided who to call to interview before selecting the successful applicant.

 

These are the successful PGRs and undergraduate students, and their projects:

Novel magnetoplasmonic core-shell nanoparticles for cancer theranostics via surface enhanced Raman spectroscopy and magnetic/photothermal hyperthermia

This project was supervised by PGR Pablo Martinez Pancorbo, working with undergraduate student Sam Treves, who graduated this summer from MPhys Physics with Astrophysics .

The project was interdisciplinary research focused on the fabrication of novel core-shell composite nanoparticles for both early-stage cancer cells imaging and treatment. It involved the nanoparticles synthesis and several materials characterizations techniques such as XRD, DLS, TEM, SEM, UV-vis spectrophotometry, Raman spectrometry, and vibrating-sample magnetometer. The project involved collaboration with with the Living Systems Institute (LSI) and Applied Magnetism Institute (IMA), Spain.

Pablo reports that all expected outcomes were achieved and as well as the scientific findings, he found transferrable skills:

I am taking several ideas out of this experience for future positions in which I manage others. The collaboration was very fluent, and we communicated effectively in a daily basis. I really enjoyed being part of this opportunity and think I will be a better manager and mentor in future roles.

Sam plans to apply for PhD positions after graduating and also grew his professional development:

My supervisor encouraged me to work independently from early on in the project. This presented problems initially as things took more time to complete and there were more obstacles that I did not know how to solve. These issues were resolved after speaking to PhD students and looking at published papers. As a result I am now able to work independently without supervision and my resourcefulness when problem solving has been enhanced.

Investigation of Coupled Elasto-Magnetic Pumps for Wireless Fluid Movement

This project was supervised by PGR Elizabeth Martin, working with final year MPhys student Tom Moynihan.

Lab-on-a-chip technology holds the key to fast, low power, portable diagnostic devices. This performs laboratory functions on one chip. In order to achieve this, there is a need for microscopic devices that can transfer fluid at this scale, which is a challenge due to viscouslike regime. This project aims to tackle this problem by employing novel elasto-magnetic devices, to manipulate liquids at microscopic dimensions. These devices will be implemented and tested which would aid in optimising the design and fabrication process. This could lead onto improvements in lab-on-a-chip technology in the future.

Elizabeth explained how the experience taught her skills outside of her usual day-to-day work:

The main skills that I have developed further through this experience (which are not so prominent in traditional day-to-day PhD work) are: motivating others to continue their research even when the preliminary results aren’t what you expect; forward-planning for people other than myself; and guiding someone in their research.

Her favourite part of the experience was seeing how her summer student enjoyed the research and she would recommend anyone who has the opportunity to give it a go.

Tom experienced the leap in difficulty from undergraduate experiments to postgraduate research:

Working on a research project without a given exact script to work from has given me the skills to work independently toward a goal with no fixed path. Working full time has allowed be to learn the skills required to manage my time efficiently, plan each day according to what I think I can do and adjust accordingly. I have also learnt how to deal with speed bumps in the research. I found when working on something that people haven’t done before (as opposed to early years undergraduate experiments where there’s a given script) there are far more difficulties to overcome in the completion of the task at hand, and overcoming these difficulties has been a large part of my learning.

From Chaos to Order: Predicting the True Interface Using First-Principles Methods 

This project was supervised by PGR Ned Taylor, working with final year MPhys student Isiah Rudkin-Crawford.

Ned’s project employed computational and theoretical methods to tackle the problems presented by interfaces by predicting the true interface between any two given materials. To make the ideal solar cell, several interfaces are needed; as such, we need to understand their attributes. These interfaces can remove, change or even create the desired properties of a device. By gaining insights into the interface, we can better understand the device.

Ned learnt many transferrable skills from his project:

I found the interview panel to be one of the most useful experiences of this programme. I had to select an interview panel and create a set of questions to gauge each candidate’s potential. This was very interesting, as the purpose of each question needed to be made clear to the panel members. Going through the Uni’s interview process was helpful in understanding the requirements of interviews and the rules under which they are conducted. For the students who were unsuccessful in this stage, I tried gave individualised, constructive feedback to each in order to help them for their next time applying for a role.

The third stage allowed me to develop and improve my skills of project management. I tried to keep close to the initially outlined plan of the project, whilst still allowing room for deviation if work merited it and if the student had some ideas they wanted to test. This project has given me the opportunity to guide a student in the development of new skills and give them goals to work towards.

Isiah felt the project had improved his scientific skills:

The project has required me to be imaginative when trying to find ways to manipulate physical systems and implement mathematical models in computational form.
Undertaking this project has significantly enhanced my programming ability. I am now competent with Fortran, a programming language that I hadn’t used before the project started and have learnt a lot of transferable coding skills that aren’t specific to the language. I have also gained significant experience working with other people’s code in a group project, which is an important and difficult skill for my future working with others on large programming projects.
The opportunity to use the University supercomputer is also a valuable experience, as it has given me insight and experience into how these devices are run, used, and managed in a professional environment.

The call out for Summer 2020 project proposals is coming soon so watch this space!

 

Julia de Pineda Gutierrez wins best student paper at IEE Radio and Antenna days of the Indian Ocean Conference

Fourth year PGR Julia de Pineda Gutierrez discusses the two conferences she recently attended and their successful outcomes:

Last month, I attended two conferences, where I had the chance to present my latest research. Between the 16th and the 21st of September I took part in the 13th International congress on Artificial Materials for novel wave phenomena (also known as Metamaterials) in Rome. I was invited to present my work in a special session organized by the Physical Review Journals. After the session there was also an opportunity to meet the Physical Review editors. The session was a showcase for the work that was published in the different Physical Review Journals the year before. I was invited to present my paper on microwave edge modes that was published in Physical Review B, titled ‘Microwave edge modes on a metasurface with glide symmetry’.

The conference was a great opportunity to make new contacts and to learn about the latest work in the field of metamaterials.

The following week, I flew to Reunion Island, a French territory in the Indian Ocean, to attend the IEEE Radio and Antenna days of the Indian Ocean conference. I also gave an oral presentation, in this case titled ‘Metasurfaces for high index effective media’.

With this, I won the best student paper competition, which included a certificate and a 300€ cash prize.

Julia’s other publications include Metasurface bilayer for slow microwave surface waves’ and ‘Hexagonal symmetry metasurfaces for broadband antenna application’.

Julia presents her latest research

Emanuele Gemo presenting his recent research at EPCOS

PGR Emanuele Gemo

Fourth year PGR Emanuele Gemo discusses his experience of presenting at this year’s E\PCOS conference.

The E\PCOS (European symposium on Phase-Change and Ovonic Science) started in 2001 as a workshop on the emerging field of phase-change material science and applications. Since then, it has been hold each year in various locations in Europe, and evolved in a conference style collecting contributions from both academic and industry research.

This year I presented my latest research work: the proposal of a novel all-photonic memory architecture, which by use of a bespoke plasmonic nanoantenna is capable to reduce both speed and energy requirements by 1 to 2 orders of magnitude with respect to the conventional configuration:

“A plasmonic route towards the energy scaling of on-chip integrated all-photonic phase-change memories

Emanuele Gemo¹, Santiago García-Cuevas Carrillo¹, Carlota Ruiz De Galarreta¹, Joaquin Faneca¹, Nathan Youngblood², Wolfram H.P. Pernice³, Harish Bhaskaran², C. David Wright¹

1-Department of Engineering, University of Exeter, North Road, Exeter EX4 4QF, UK
2-Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
3-Institute of Physics, University of Muenster, Heisenbergstrasse 11, 48149 Muenster, Germany

ABSTRACT

Phase-change photonic memory devices, conventionally implemented as a thin layer of phase-change material deposited on the top of an integrated Si or SiN waveguide, have the flexibility to be applied in a widely diverse context, as a pure memory device, a logic gate, an arithmetic processing unit and for biologically inspired computing. In all such applications increasing the speed, and reducing the power consumption, of the phase-switching process is most desirable. In this work, therefore, we investigate, via simulation, a novel integrated photonic device architecture that exploits plasmonic effects to enhance the light-matter interaction. Our device comprises a dimer nanoantenna fabricated on top of a SiN waveguide and with a phase-change material deposited into the gap between the two nanoantenna halves. We observed very considerably increased device speeds and reduced energy requirements, of up to two orders of magnitude, when compared to the conventional structure.”

The conference has been extremely interesting, as it spanned within various field: material science, optical and photonics applications, electronic devices and new applications such as neuromorphic computing. The time spent there has been undeniably valuable, and many presentations provided with lots of new ideas to be explored.
I also had the chance to meet in person with different academics and industry researchers. Among these, I have opened a channel of communication with a representative from Advanced Materials, with the view to further develop a modelling framework I contributed to build in the past.

Ioannis Leontis in conferences at Washington DC

Third year PGR and vice-president of EUOPS (Exeter University Optics and Photonics Society) Ioannis Leontis discusses his experience of two conferences he was recently invited to:

In September 2019, as vice-president of EUOPS (Exeter University Optics and Photonics Society), I was invited to participate in two OSA (Optical Society of America) conferences in Washington DC. The first one, Leadership Conference 2019 (SLC 2019), was mainly focused on students in optics and included were workshops for improving student skills, transitioning from student to professional and choosing a profession. Moreover, there were very interesting presentations about hot topics in photonics, such as a presentation about the new Infrared Space Telescope of NASA “James Webb”. Concerning the second one, OSA Frontiers in Optics and Laser Science conference 2019 (FiO+LS 2019), it was a very interesting technical conference in optics with multiple parallel sessions about Nanophotonics and Plasmonics, Quantum Technologies, and photonics application in biology including a plenary talk of Nobel Prize Laureate in Physics. In general, both OSA conferences were of great scientific interest and it was a great opportunity for improving my scientific networking and to expand my scientific horizon in optics.

Connor Sait at ‘Quantum Matter Out of Equilibrium’ summer school

Second year PGR Connor Sait talks about his experience at ‘Quantum Matter Out of Equilibrium’ summer school:

 

Between the 1st and 5th of September I took part in the ‘Quantum Matter Out of Equilibrium‘ Summer school in Granada, Spain. The school was the fifth of its kind and was organised by Rosario González-Férez (University of Granada), Igor Lesanovsky and Beatriz Olmos (University of Nottingham).

My research with Janet Anders and Simon Horsley involves the application of quantum non-equilibrium techniques to the theory of ferromagnetic materials, so the school was a great opportunity for me to meet new people who use similar techniques, and learn from their understanding and experience. I learned a lot from the lectures that took place and it really helped me to both solidify my own understanding of certain concepts, and broaden my perspective of the field. The lectures were a mixture of theory and experimental talks and were pitched at a good level for somebody at the early to middle stages of their PhD in a related topic.

I also made a number of friends from several European groups in the field – people from places like the CANES CDT (Kings College London) and the theoretical and computational physics groups at the Technical University of Berlin. Talking with the other PhD students, I was able to resolve many of my questions and correct misunderstandings in a casual and relaxed manner. By giving me a better understanding of the research my peers in the field are conducting, the event has also helped me to feel more comfortable with my own research and identify where it fits in, and contributes to the wider physics community.

Early in the event I gave a poster presentation in the poster session, which was a great chance to ask others about their work and to learn how to communicate my own research. We later enjoyed a conference dinner together, and visited La Alhambra, a mesmerising palace and fortress with a medieval Islamic design.

It was a great experience and a fantastic way to wrap up my first year here at the Exeter Metamaterials CDT.

CDT Team Building Away Day!

Third year PGR student and SAG rep Emily Glover reports on this year’s CDT Away Day, a team building activity which rounded off Induction Week:

Following on from the tradition which was started last year, the last day of Induction Week (20th September) found PGRs from all years taking part in a variety of activities for team building and get to know the CDT’s newest cohort. It was a welcome change for the older cohorts, taking a break from their normal days in the lab or at the computer, and a chance for the newest cohort to get to know people the best way possible, by lifting them through rope holes in the name of team building. This year, we went to Shillingford Organics farm for a day of activities hosted by Exeter Forest School.

Splitting up into four groups, we took part in a range of activities to improve our communication, team work, and mindfulness to stop life from becoming overwhelming. Lunchtime gave everyone an opportunity to relive a staple of British secondary school PE (and show those who didn’t go to school in the UK how no-one remembers the rules of secondary school sports) with a quick game of one-hit rounders. While it might not have been a professional game of rounders, with many missed throws and a few bruises, everyone had a smile on their face and were ready for their afternoon activities.

Overall, everyone enjoyed themselves, learning new faces and skills that we will be able to bring into our day-to-day lives, and some survival skills should we ever find ourselves lost in a forest, needing to build and subsequently set fire to a woodland creature made out of willow (which a whale clearly is, according to our panel of physicists).

More photos from the day below: