Jake Mehew‘s work on an optical isolator circuit which grants access to high-impedance states by electrically decoupling the current-injection from the voltage-sensing circuitry has recently been published in AIP Review of Scientific Instruments: “Two-dimensional materials offer a novel platform for the development of future quantum technologies. However, the electrical characterisation of topological insulating states, non-local resistance, and bandgap tuning in atomically thin materials can be strongly affected by spurious signals arising from the measuring electronics. Common-mode voltages, dielectric leakage in the coaxial cables, and the limited input impedance of alternate-current amplifiers can mask the true nature of such high-impedance states. Here, we present an optical isolator circuit which grants access to such states by electrically decoupling the current-injection from the voltage-sensing circuitry. We benchmark our apparatus against two state-of-the-art measurements: the non-local resistance of a graphene Hall bar and the transfer characteristic of a WS2 field-effect transistor. Our system allows the quick characterisation of novel insulating states in two-dimensional materials with potential applications in future quantum technologies.” See the full article in Review of Scientific Instruments, Volume 89, Issue 2, DOI 10.1063/1.5020044
In need of a break? Try this for a bit of a change:
Ever played the game Tetris? There’s the possibility to completely clear the board after the first five pieces are placed in a block that’s 10 x 2 squares wide/high. Can you figure out how many different arrangements of Tetris pieces there are to make this happen?
Too easy? Got another one? Please email your riddle suggestions to
The solution to last newsletter’s riddle (I am a three digit number. My second digit is four times more than my third digit. My first digit is seven less than my second digit. What Am I?): 182.
Tanveer Tabish is the first XM2 PGR to submit his PhD thesis (15 February 2018). Please see the abstract of his thesis below. Tanveer is supervised by Shaowei Zhang and Yongde Xia and he published more than 10 journal articles and conference proceedings during his time in the CDT for Metamaterials, for example in the International Journal of Nanomedicine, Nanotechnology, Redox Biology, Scientific Reports, and at the IEEE Nanotechnology Materials and Devices conference (2016), respectively. Tanveer spent 3 months on a research visit at the Politecnico di Milano (Italy) in 2017, and arranged multiple short-term research stays with collaborators at the University of Oxford, King’s College London, and the University of Newcastle. He went to various national and international conferences and workshops, for example in Oxford (UK), Antalya (Turkey), Toulouse (France) and Chennai (India) where he presented his work via posters and presentations. Tanveer won a presentation prize at the 22nd CSCST-SCI Conference for Renewable energy and novel materials for a sustainable future (Birmingham, 2015) and gave an invited talk on “Fabrication of graphene nanopres for application in marine biology” at a workshop organized by British Council and Royal Society of Chemistry the at the Middle East Technical University in Ankara (Turkey, 2017) .
We are incredibly proud of Tanveer and hope he will be successful with his applications to embark on a career in academia in the UK.
Well done Tanveer!
PhD thesis abstract Tanveer Tabish: DEVELOPMENT OF GRAPHENE NANOSTRUCTURES FOR USE IN ANTI-CANCER NANOMEDICINE
Nanomedicine utilises biocompatible nanomaterials for therapeutic as well as imaging purposes, for the treatment of various diseases including cancer, neurological disorders and wound infections. Graphene, a material composed of a single layer of carbon atoms, has recently shown great potential to improve diagnostics and therapeutics, owing to its small size, large surface-area-to-volume ratio and unique physicochemical properties. However, the limited fabrication, in vitro and in vivo functionalities published in the literature indicate inconsistencies regarding the factors affecting metabolic fate, biodistribution as well as toxicity patterns of graphene. This thesis focuses on the biological effects of graphene-based materials, including graphene oxide (GO), reduced graphene oxide (rGO), graphene nanopores (GNPs), graphene quantum dots (GQDs) and three-dimensional graphene foam (GF). These can be used to closely mimic therapeutic functions and thereby open up new pathways to anticancer nanomedicine. In this work, a biocompatible GO-based anti-metastatic enzyme cancer therapy approach has been introduced for the first time to target the extracellular pro-metastatic and pro- tumourigenic enzymes of cathepsin D and cathepsin L, which are typically overexpressed in ovarian and breast cancers. Definitive binding and modulation of cathepsin- D and -L with GO has revealed that both of the enzymes were adsorbed onto the surface of GO through its cationic and hydrophilic residues under the biologically relevant condition of acidic pH. It has been demonstrated that low concentrations of rGO were shown to significantly produce late apoptosis and necrosis rather than early apoptotic events in lung cancer cells (A549 and SKMES-1), suggesting that it was able to disintegrate the cellular membranes in a dose-dependent manner. GNPs at lower concentrations (250µg/ml) induce upregulation of phosphatidylserine on cell surface membrane (i.e. early apoptotic event), which does not significantly disintegrate the cell membrane in the aforementioned lung cancer cells, while higher concentrations of GNPs (5 and 15 mg/kg) in rats (when intraperitoneally injected) exhibited sub-chronic toxicity in a period of 27 days. The interaction of GQDs and trypsin has revealed the strong bonding capacity of GQDs with trypsin, owing to their surface charge and surface functionalities evidencing the high bioavailability of GQDs in enzyme engineering. Finally, 3D GF was developed to probe the role of graphene-based scaffold cues in the field of regenerative medicine revealing their cell attachment to in vitro cell cultures. Furthermore, GF was shown to maintain remarkable biocompatibility with in vitro and in vivo toxicity screening models when exposed for 7 days at doses of 5, 10 and 15 mg/l. Taken together, graphene and its modified structures developed in this thesis promise to revolutionise clinical settings across the board in nanomedicine which include, but are not limited to, ultra-high sensitive enzyme adsorbents, high throughput biosensors, enzyme modulators and smart scaffolds for tissue regeneration.
On 13 February 2018 the XM2Oversight Board (OB) visited us to evaluate the progress our centre has made over the last 6 months.
The day’s agenda saw a few ‘firsts’ as highlights of the day:
Prof Alastair Hibbins gave his first talk as Director of the CDT to the OB – an open session to which all supervisors and PGRs were invited;
Our first cohort, now approaching graduation, met with the OB to provide feedback on their experiences in the centre over the past 4 years;
Our latest intake (2017/18) attended the meeting for the first time – and they did a great job presenting posters of their current work to the Oversight Board.
The OB, the XM2 Management Board (MB) and our Student Advisory Group had an engaged discussion that included ideas about how to best utilise the OB members’ time and experience to the benefit of future PGRs – a proposal following the discussion will be developed together with the student body over the next months. In addition, the PGRs made valuable suggestions on the training elements of the programme which will be taken into consideration for both the current centre and the new proposal.
Overall, the OB’s impressions of the centre’s development (based on the biannual report and communication with PGRs and MB on the day) are rather positive. In particular, the increase in research outputs and the enhanced profile raising activities (website, blog, CDT videos) to showcase the breadth of our research and the PGRs activities were very well received. A key item of the OB recommendations for future improvement is the engagement of the supervisor body with CDT events and the training progamme. Following sign off of the OB feedback summary we will communicate the details of the recommendations made.
Joaquin gave a presentation on his recent research results on integrated 2D materials in silicon nitride platformin in the Silicon Photonic section, and presented a poster in a section devoted to Optical Interconnects. Liam presented a poster summarising his work on tunable metamaterial band-pass filters. Our PGRs appreciated the opportunity to liaise with international representatives from both the scientific and the industry community. The event provided an excellent platform to gain insights in the latest developments of the sector, e.g. outlined in Stephen G. Anderson’s presentation on the strength of the photonics market.
The PGRs also got to enjoy the social and cultural aspects of the conference – from active team work during evening sessions to cycling around the bay and visiting Alcatraz. Joaquin and Liam returned to Exeter being fully enthused by their experience. In Joaquin’s words: “It was simply fantastic!”
Julia De Pineda Gutiérrez has joined our Student Advisory Group (SAG) to co-represent the 2016 cohort for the remainder of the academic year 2017/18. Zahid Hussain has stepped down due to his extended research stay in Germany.
The Student Advisory Group consists of normally 2 members of each cohort who represent the student body at meetings with the Management and Oversight Boards and the Programme Manager. They help to implement new ideas that benefit the overall experience of their peers, to offer different perspectives, and to ensure the PGRs’ opinions are heard. SAG is currently chaired by Ben Hogan, one of our 3rd year PGRs.
has published his latest article on “A new class of magnetically actuated pumps and valves for microfluidic applications” in Scientific Reports in Jan 2018. The research team proposes a new class of magnetically actuated pumps and valves that could be incorporated into microfluidic chips with no further external connections. The idea is to repurpose ferromagnetic low Reynolds number swimmers as devices capable of generating fluid flow, by restricting the swimmers’ translational degrees of freedom. Read more…
The use of two-dimensional graphene-based materials in water treatment has recently gained significant attention due to their unique electronic and thermal mobility, high surface area, high mechanical strength, excellent corrosion resistance and tunable surface chemistry. However, the relatively expensive, poor hydrophobicity, low adsorption capacity and recyclability, and complex post-treatment of the most pristine graphene frameworks limit their practical application. Here, we report a facile scalable method to produce highly porous graphene from reduced graphene oxide via thermal treatment without addition of any catalyst or use of any template. Read more…