- Date:
- 2012-2017
- Themes:
- Nanoelectronics, Photovoltaics and Energy
- Funding:
- EPSRC
Summary
An alternative paradigm for enhancing the light utilisation in photovoltaic (PV) devices is the use of nano-particles of metals in order to make superior use of the optical field. Since the size and shape of nano-particles act as tuning variables for plasmonic effects, it should be possible to design schemes to enhance different PV technologies in wavelength regions where they could perform better. The structures could be introduced at various interfaces within a PV device. Issues are surface recombination and absorption losses, both of which are potentially significant if the density of nanoparticles is high.In order to thoroughly understand the influence of plasmonics on the PV materials and devices by experiment, carrier lifetime measurements and photoconductivity measurements can be performed. The aim of this project is to produce a test platform which can be used to measure the change in photoconductivity of a thin layer of silicon due to the presence of a variety of plasmonic nanostructures on the surface.
Method
We have chosen the asymmetric metal-semiconductor-metal photodetector as the basis for our plasmonic structure test platform as these devices are known to have fast response times and high sensitivities. We are optimizing the dimensions of the MSM photodetector, such as distance between metal fingers, width and lengths of metal fingers, thickness of the silicon device layer and thickness of the SiO2 passivation layer using simulations built in Athena/Atlas software. The simulation results are being used to guide the design of MSM devices for our plasmonic structure test platform. Fabrication of the initial MSM devices is currently underway.Next steps
Following fabrication and testing of the MSM devices, plasmonic structures will be placed in between the metal fingers using ebeam lithography and lift-off or deposition from a liquid suspension. Photoconductivity measurements will then be performed using the IV characteristic measurement systems.Key References
1. Barnard, E. S.; Pala, R. A. and Brongersma, M. L. ââ¬ÅPhotocurrent mapping of near-field optical antenna resonancesââ¬?, Nature Nanotechnology, 2011, 9, 588-593 2. Chui, C. O.; Okyay, A. and Saraswat, K. ââ¬ÅEffective dark current suppression with asymmetric MSM photodetectors in Group IV semiconductorsââ¬?, Photonics Technology Letters, IEEE, 2003, 15, 1585-1587 3. Sesuraj, Rufina S.A.; Temple, T.L. and Bagnall, D.M. ââ¬ÅOptical characterisation of a spectrally tunable plasmonic reflector for application in thin film silicon solar cells.ââ¬? Solar Energy Materials and Solar Cells, 2013, 111, 23-30.Primary investigators
- Pavlos.Lagoudakis
- Stuart Boden
- Asa Asadollahbaik
Secondary investigator
Associated research group
- Nano Research Group
- Date:
- 2013-2018
- Theme:
- Energy Harvesting
- Funding:
- EPSRC (EP/K031910/1)
The UK's healthcare system faces unprecedented challenges. We are the most obese nation in Europe and our ageing population is especially at risk from isolation, depression, strokes and fractures caused by falls in the home. UK health expenditure is already very substantial and it is difficult to imagine the NHS budget rising to meet the future needs of the UK's population. NHS staff are under particular pressure to reduce hospital bed-days by achieving earlier discharge after surgery. However this inevitably increases the risk that patients face post operative complications on returning home. Hospital readmission rates have in fact grown 20% since 1998. Many look to technology to mitigate these problems - in 2011 the Health Minister asserted that 80% of face-to-face interactions with the NHS are unnecessary.
SPHERE envisages sensors, for example:
1) That employ video and motion analytics to predict falls and detect strokes so that help may be summoned.
2) That uses video sensing to analyse eating behaviour, including whether people are taking their prescribed medication.
3) That uses video to detect periods of depression or anxiety and intervene using a computer-based therapy.
The SPHERE IRC will take a interdisciplinary approach to developing these sensor technologies, in order that:
1) They are acceptable in people's homes (this will be achieved by forming User Groups to assist in the technology design process, as well as experts in Ethics and User-Involvement who will explore issues of privacy and digital inclusion).
2) They solve real healthcare problems in a cost-effective way (this will be achieved by working with leading clinicians in Heart Surgery, Orthopaedics, Stroke and Parkinson's Disease, and recognised authorities on Depression and Obesity).
3) The IRC generates knowledge that will change clinical practice (this will be achieved by focusing on real-world technologies that can be shown working in a large number of local homes during the life of the project).
The IRC "SPHERE" proposal has been developed from day one with clinicians, social workers and clinical scientists from internationally-recognised institutes including the Bristol Heart Institute, Southampton's Rehabilitation and Health Technologies Group, the NIHR Biomedical Research Unit in Nutrition, Diet and Lifestyle and the Orthopaedic Surgery Group at Southmead hospital in Bristol. This proposal further includes a local authority that is a UK leader in the field of "Smart Cities" (Bristol City Council), a local charity with an impressive track record of community-based technology pilots (Knowle West Media Centre) and a unique longitudinal study (the world-renowned Avon Longitudinal Study of Parents and Children (ALSPAC), a.k.a. "The Children of the Nineties").
SPHERE draws upon expertise from the UK's leading groups in Communications, Machine Vision, Cybernetics, Data Mining and Energy Harvesting, and from two corporations with world-class reputations for research and development (IBM, Toshiba).
Primary investigator
Secondary investigators
Partners
- University of Bristol
- University of Reading
Associated research group
- Electronics and Electrical Engineering
- Date:
- 2006-2016
- Funding:
- Ministry of Defence, U.S. Army Research Laboratory
The International Technology Alliance in Network and Information Sciences (ITA) is a collaborative research alliance between the UK Ministry of Defence (UK MoD) and US Army Research Laboratory (US ARL), and a consortium of leading academic and industry partners. The ITA programme started on May 12, 2006 with the strategic goal of producing fundamental advances in information and network sciences that will enhance decision making for coalition operations and enable rapid, secure formation of ad hoc teams in coalition environments and enhance US and UK capabilities to conduct coalition warfare. The first phase of the ITA programme finished in 2011, and now the programme is in its second phase (May 2011-May 2016).
The ITA consortium is led by IBM - with one of the largest and most admired commercial research and development (R&D) programmes in the world. The consortium includes recognised military domain experts including some of the major defence system integrators in the US (Raytheon BBN Technologies, The Boeing Company, Honeywell, Applied Research Associates) and UK ((LogicaCMG, Roke Manor Research Limited, SEA). The academic partners include top-notch universities both in US (Carnegie Mellon University; City University of New York; Columbia University; Pennsylvania State University; Rensselaer Polytechnique Institute; University of California, Los Angeles; University of Maryland, College Park; University of Massachusetts, Amherst) and in UK (Cranfield University; Imperial College, London; Royal Holloway; University of London; University of Aberdeen; University of Cambridge; University of Southampton; University of York).
Text from US UK ITA.
Primary investigator
- ps02v
Secondary investigator
- dpr1g09
Partners
- Carnegie Mellon University
- IBM
- EADS
Associated research group
- Web and Internet Science
- Date:
- 2010-2014
- Themes:
- Bionanotechnology and Biosensors, Microfluidics and Lab-on-a-chip
- Funding:
- EPSRC (studentship), ECS studentship contribution
Electrical measurements of ion channel activity can be performed by patch clamping of cell membranes or by suspending lipid bilayer model membranes, with incorporated channels, in an aperture positioned inbetween two aqueous compartments. The latter method is in principle more suitable for miniaturization, parallelization and automation of ion channel measurements, but it critically depends on the stability of the suspended bilayer. Conventional apertures in thin Teflon sheets have a diameter of ~150 õm and are produced by mechanical punching or electric sparks. These methods do not give reproducible aperture geometries and consequently only a number of apertures are suitable for suspended bilayer formation, and even these tend to be relatively fragile, limiting measurement throughput.
In this project we fabricate apertures in photoresist sheets by 3D lithography, which enables not only precise control of the aperture diameter but also of the shape of the aperture side walls. Ideally the sheets should be relatively thick to reduce the capacitance of the septum, but it is hypothesized that a thinner aperture edge improves bilayer stability. We have shown that bilayers formed at the thin tip of our tapered apertures display drastically increased lifetimes, typically >20 hours, and mechanical stability, being able to withstand extensive perturbation of the aqueous compartments as required for ion channel assays. Single-channel electrical recordings of peptides and proteoliposome-delivered channels demonstrate channel measurements with low noise, enabling observation of the ~10 pA channel current steps.
These shaped apertures with micrometer edge thickness should substantially enhance the throughput of channel characterisation by bilayer lipid membrane electrophysiology, especially in combination with automated parallel bilayer platforms, which are developed in a related project.
Primary investigators
Secondary investigator
- Mr Sumit Kalsi
Partner
- Birkbeck College, University of London
Associated research group
- Nano Research Group
- Date:
- 2013-2014
- Funding:
- EPSRC
BluPointââ¢, will provide a physical content provisioning access point to enable people in off-grid, low resources, communities to access digital materials on their mobile phones and create/share their own digital content. BluPointâ⢠uses Bluetooth as the local data carrier, which is supported on both smart and non-smart phones alike and is widely used to transfer digital artefacts in LEDCs as it is free. It is envisioned that BluPointâ⢠will be located in rural health centres, schools, commercial centres, taxiââ¬â¢s, water wells and other places that people naturally gather. BluPointâ⢠will be used for both content and service provision for commercial, health, government, local-community and entertainment sectors.
The ITaaU funding will enable an investigation and subsequent delivery of a scoping report covering two case studies of potential BluPoint: one in Africa and the other in India. The investigation will focus on user experiences derived in BluPoint created Smart Spaces.
Primary investigator
Secondary investigator
- mhds
Partners
- ITaaU
- SetSquared
Associated research group
- Electronic and Software Systems
- Date:
- 2009-2011
- Themes:
- High Voltage Engineering, Condition monitoring
- Funding:
- UK Power Networks
Power distribution cable networks are inherently inaccessible and complex systems; many of them are coming to the end of their expected lifespan and are being loaded beyond their original design specifications. The ability to accurately monitor and record the real-time health of these systems is of vital importance to utility companies for activities such as planning, asset management, and pin-pointing possible weaknesses of the network. Partial Discharge (PD) activity has been highlighted as both a cause and symptom of electrical degradation of high voltage equipment. Utilities increasingly use the analysis of PD signals to make more robust maintenance and asset replacement decisions. Additionally, it reduces the likelihood of future supply interruption, and allows replacement or repairs to be planned in advanced. Finally, the use of on-line PD sensing systems can reduce costly down time and help to avoid catastrophic failures.
An EDF Energy Networks sponsored project is taking place at the Tony Davies High Voltage Laboratory, University of Southampton. It involves the introduction of known faults into medium voltage three-phase PILC cable and aims to closely replicate operational conditions. The results produced by the experimental rig in the lab will be obtained using conventional techniques covered by IEC 60270, in parallel with commercially available PD monitoring equipment that is installed in distribution networks worldwide. It is hoped that the research being undertaken will develop the understanding of fault progression with respect to 11 kV three-phase PILC cables.
Primary investigators
- jah1c12
- Paul Lewin
Partner
- UK Power Networks
Associated research group
- Electronics and Computer Science
- Date:
- 2011-2015
- Themes:
- Microfluidics and Lab-on-a-chip, Bionanotechnology and Biosensors
- Funding:
- University PGR studentship, FPSE funding
Molecular diagnostic tools need to be capable of detecting specific biomolecules that serve as an indicator for a disease state, ideally in a robust and easy to use format, enabling implementation as a point-of-care device. As sample collection should be minimally invasive and not require specific medical expertise or qualifications, blood fingerprick samples (~20 õL) are particularly attractive. Nanoscale field effect transistors are being explored as disposable point-of-care molecular diagnostic devices in the TSB/EPSRC-funded project "Low cost nanowire diagnostic platform" (see link below). However, nanoFET assays require a low, 1 mM or less, salt concentration to avoid Debye screening of antibody-bound analyte molecules and hence require a sample preparation step. For nanoFET analysis of blood biomarkers, this cannot be achieved by dilution of the sample because this could result in biomarker concentrations below the detection limit of the assay. In this project we are developing a simple dialysis cell which can remove a desired amount of salt by adjustment of the sample and water flow rates, while biomarkers with a molecular weight exceeding a set threshold value are retained. The cell is based on a cross-flow dialysis configuration with millifluidic channels on both sides of a track-etched membrane, enabling low sample volumes as required for fingerprick blood samples.
Primary investigator
Secondary investigator
- Prameen Kalikavunkal
Associated research group
- Electronics and Electrical Engineering
- Date:
- 2013-2016
- Theme:
- Novel Sensors
- Funding:
- CP-FP-INFSO-FP7-610414
CREATIF provides the CCI with a creative experience collaborative tool consisting of intuitive software design tools coupled to a digital dispenser printer allowing them to create bespoke smart fabrics by printing. The design tools consist of software to collaboratively design, layout, visualise and simulate smart fabrics which are then produced using a dispenser printer; conventional fabrics are functionalised by printing active electronic inks. 'Visualisation' and simulation will interact in the collaborative design process with the senses of sight (through a monitor image), hearing (through Skype and by the smart fabric function of sound emission from the PC speakers) and touch (through the use of touch screens for design and the simulation of the feel of the fabric and the feeling of being touched on a haptic PC screen).
CREATIF offers to the CCI the ability to transform everyday fabrics into knowledge intensive smart fabric based creations incorporating a high level of intellectual creative content, by mass customisation of basic templates, or in one off designs.
The consortium consists of a design software developer (Grafixoft), a university specialised in fabric machine design (University of Aachen), a university with world leading expertise in creating smart fabrics by printing (University of Southampton), a creative design SME (Diffus Design), an SME, active in design-led building structures and architecture (Base Structures), a large company active in architecture and creative design (Zaha Hadid) and an SME specialised in advanced inkjet printers (Ardeje). We demonstrate the creative experience tools use in a real environment by producing, within CREATIF, three advanced smart fabric prototypes (for interactive light emission, interactive colour change and sound emission/touch) and apply them in two applications relevant to the CCI: an interactive, modular blind and exhibition stand. These directly target the CCI of design, advertising and architecture although the collaborative tool impacts any CCI using fabrics.
Primary investigators
Secondary investigators
- Steve Beeby
- Neil Jonathan Grabham
- Kai Yang
- yw1f10
- yl1g08
- mdv1g10
- za2g13
Partners
- RHEINISCH-WESTFAELISCHE TECHNISCHE HOCHSCHULE AACHEN
- Grafixoft
- Diffus Design
- Base Structures Ltd
- Zaha Hadid Architects
- Ardeje
Associated research group
- Electronics and Electrical Engineering
- Date:
- 2011-2015
- Themes:
- Bionanotechnology and Biosensors, Microfluidics and Lab-on-a-chip
White blood cells play a central role in the bodyââ¬â¢s defence against bacterial, viral and fungal pathogens. In blood, there is only one white blood cell for every 1000 red blood cells, which makes their isolation a difficult task. Conventional isolation methods such as membrane filtration, differential centrifugation, or selective lysis of red blood cells could result in altered immune-phenotype or impaired viability of isolated WBCs and require a relatively large volume of blood.
In this project we have developed a microfluidic system with hydrodynamic cell traps that selectively capture white blood cells while not obstructing the flow path for red blood cells and platelets. The traps and therefore the immobilized cells are optically accessible, presenting an array of leukocytes that can be studied, at a sub-cellular level, with conventional biochemical labelling methods.
Whilst cell arrays are of general interest for cell population heterogeneity studies, e.g. different responses to external stimuli, our initial focus is on establishing nanoparticle association and uptake for different white blood cell types, identified by antibody labelling of distinct membrane receptors.
Primary investigator
Secondary investigator
- Hend I. Alkhammash
Associated research group
- Electronics and Electrical Engineering
The project concerns the fabrication of low optical loss polysilicon waveguides deposited using Hot-Wire Chemical Vapour Deposition (HWCVD) at a temperature of 240C. A polysilicon film of 220 nm thick was deposited on top of a 2000 nm thick PECVD silicon dioxide. The crystalline volume fraction of the polysilicon film was measured by Raman spectroscopy to be 91%. The optical propagation losses of 400, 500, and 600 nm waveguides were measured to be 16.9, 15.9, and 13.5 dB/cm, respectively, for transverse electric (TE) mode at the wavelength of 1550 nm.
Primary investigator
- Harold M. H. Chong
Secondary investigators
- T M B Masaud
- A Tarazona
- Graham T Reed
- Goran Z Mashanovich
Associated research groups
- Nano Research Group
- Optoelectronics Research Centre