The global semiconductor market has a value of around $1trillion, over 90% of which is silicon based. In many senses silicon has driven the growth in the world economy for the last 40 years and has had an unparalleled cultural impact. Given the current level of commitment to silicon fabrication and its integration with other systems in terms of intellectual investment and foundry cost this is unlikely to change for the foreseeable future. Silicon is used in almost all electronic circuitry. However, there is one area of electronics that, at the moment, silicon cannnot be used to fill; that is in the emission of light. Silicon cannot normally emit light, but nearly all telecommunications and internet data transfer is currently done using light transmitted down fibre optics. So in everyones home signals are encoded by silicon and transmitted down wires to a station where other (expensive) components combine these signals and send light down fibres. If cheap silicon light emitters were available, the fibre optics could be brought into everyones homes and the data rate into and out of our homes would increase enormously. Also the connection between chips on circuit boards and even within chips could be performed using light instead of electricity. The applicants intend to form a consortium in the UK and to collaborate with international research groups to make silicon emit light using tiny clumps of silicon, called nanocrystals;. These nanocrystals can emit light in the visible and can be made to emit in the infrared by adding erbium atoms to them. A number of techniques available in Manchester, London and Guildford will be applied to such silicon chips to understand the light emission and to try to make silicon chips that emit light when electricity is passed through them. This will create a versatile silicon optical platform with applications in telecommunications, solar energy and secure communications. This technology would be commercialised by the applicants using a high tech start-up commpany.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

We are living in an exceptional age for discoveries in particle physics and particle astrophysics with potential for producing step changes in understanding of the composition of matter and the structure of the Universe. The research we plan with this consolidated grant in particle physics and particle astrophysics at Sheffield is at the core of these discoveries. Firstly, we appear to be near answering the fundamental question of what gives particles mass. In this field Sheffield will continue to play a leading role in the ATLAS experiment that now looks to be on the verge of solving the mystery by detecting the famous Higgs Boson. Our ATLAS work, where we are currently the only UK group heavily involved in the flagship 4-lepton channel Higgs search, will aim to confirm the first evidence for excess reported in Dec. 2011. Simultaneously work will continue in the equally fundamental hunt to find supersymmetric particles and on radiation modeling and detector tests for the ATLAS upgrade anticipated as the next experiment. We currently provide the UK spokesman for ATLAS. A second recent major advance, made by the T2K experiment in 2011, reports evidence for a non-zero third neutrino mixing angle. This potentially unlocks progress to experiments in so-called charge-parity (CP) violation to answer the mystery of why the Universe contains matter and virtually no anti-matter. Our T2K and neutrino group will focus on contributing further analysis to confirm the new results but also, using our membership of the LBNO and LBNE collaborations, progress key new detector technology towards a next generation long baseline neutrino experiment to see CP violation. For this our focus will be with liquid argon technology, our pioneering work on electroluminescence light readout for that, and our simulation work on backgrounds from muons. The latter is key also to our on-going work towards an experiment to see if the proton decays, an issue at the core of understanding Grand Unified Theories of physics. Closely related and vital for our neutrino programme is continued participation in SNO+, aimed at understanding solar neutrinos, and the MICE experiment with its related R&D on high power particle beam targets for future neutrino beams. Technological developments recently led to significant improvement in sensitivity of detectors to WIMP dark matter with key contributions from the Sheffield group towards EDELWEISS and DRIFT. Exploiting our leadership in background mitigation strategy, calibration and data analysis, our future work will concentrate on EDELWEISS operation and data analysis, as well as on developments towards ton-scale cryogenic experiment EURECA. The group is also uniquely well positioned to contribute through new work aiming to see, or exclude, a definitive galactic signature for the claimed low mass WIMP events. Our pioneering work on directional WIMP detectors will see a new experiment installed at the UK's Boulby underground site, DRIFTIIe, while our continued analysis of data from DM-ICE17 at the Antarctic South Pole, for which we supplied the NaI detectors, will seek an annual modulation galactic signature and inform design of a new experiment there planned for 2013. Our generic detector R&D is vital to underpinning the group, closely related to a vigorous knowledge exchange programme that now includes funded projects involving 15 different companies. Highlight activity here will include development of particle tracking technology in liquid argon relevant to neutrino physics and astrophysics, new gas-based directional neutron programmes with relevance for homeland security, and new muon veto R&D. The latter links to our KE programme on CO2 underground storage technology. We plan first deployment of test detectors at 760m depth by 2013. This is part of the group's contribution to key social agendas in climate change and crime prevention.

There are many different types of microphones: their primary function is transduction: converting pressure waves (within some range of frequencies) into a single electrical signal, usually as precisely as possible. After this, the signal may be used for recording or for interpretation (which is our interest here). A major problem in interpretation is that the signal may have a large amount of energy in some parts of the auditory spectrum, but much less in others, and that this distribution may alter rapidly. Often, it is the energy in these lower energy areas that is critical for interpretation. Current practice is to filter the single electrical signal from the microphone (whether using FFTs, or bandpass filters), then examine the signal so produced. We propose a different approach in which the pressure wave is directly transduced into multiple electrical signals, corresponding to different parts of the audible spectrum. By making the transducers active (i.e. providing them with a rapidly adjusting gain control), we will be able to increase the sensitivity of the filters in those areas where additional sensitivity can be useful in the interpretation task, and reduce the sensitivity in those areas where the signal is very strong. The auditory interpretation tasks undertaken by animals (solving the what and where tasks when there are - as is normally the case - multiple sound sources in a reverberant environment) is the same task that an autonomous robot's auditory system needs to undertake. Animal hearing systems include multiple transducers, and provide numerous outputs for different parts of the spectrum, whilst adjusting their sensitivity and selectivity dynamically. Current microphones provide a single electrical output, which is then either processed into a number of bandpass streams (maintaining precise timing), or into a sequence of FFT-based vectors, such as cepstral coefficients (losing timing precision). The proposed active MEMS microphone performs the spectral breakdown at transduction, providing an inherently parallel output whilst maintaining precise timing. Further, it is adaptive. This adaptive capability, non-existent in current microphones is important in hearing aids. Precise timing information is important for source direction identification using inter-aural time and level differences. Where there are multiple active sources, accurate foreground source interpretation requires some degree of sound streaming, requiring the ability to examine features of the sound, often in spectral areas which with relatively low energy.The active MEMS bandpassing microphone will consist of a membrane which will vibrate due to the external pressure wave. The membrane is physically linked to different resonant elements (bars) in the MEMS structure - these elements will have a range of resonant frequencies. Further, these bars will act as gates for MOS transistors, resulting in their vibration modulating the current passing through these transistors. The modulated current will be coded as a set of sequences of spikes, and these spikes processed to provide a signal to adjust the sensitivity of each of the resonators by using an electrostatic effect to change the response of the transistors to the vibration of the bars. The modulation will be used to adjust the gain so that quiet areas of the spectrum are selectively amplified and loud areas of the spectrum selectively attenuated. In this way, it will be possible to build an integrated MEMS/CMOS microphone which can attenuate loud areas of the spectrum concurrently with amplifying quiet areas of the spectrum. The spike coded output will be made available in a way compatible with the address-event representation (AER), making it compatible with existing and proposed neuromorphic chips form other laboratories.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.