Publications
551 results found
Prodromakis T, Michelakis K, Toumazou C, 2010, Switching mechanisms in microscale Memristors, Electronic Letters, Vol: 46, Pages: 63-65
It is only very recently that the memristor, the fourth missing passive element, was discovered, as technological advances and the scaling down to nanometre dimensions in particular resulted in clearly evident and measurable memristance. At the nanoscale, these devices exhibit variable resistive behaviour, which can be applied in switching networks and memory. Experimental evidence is provided that micrometre-size memristors are viable with practical ROFF/RON ratios.
Degenaar P, Grossman N, Berlinguer-Palmini R, et al., 2010, Optoelectronic microarrays for retinal prosthesis, IEEE Biomedical Circuits and Systems Conference, BioCAS 2009, Pages: 183-186
Prodromakis T, Papavassiliou C, Toumazou C, 2010, Application of Maxwell-Wagner Polarization in Delay Lines, Microelectronics Journal, Vol: 41, Pages: 17-24
The propagation characteristics of metal–insulator–semiconductor (MIS) lines are controlled by the resistivity of the substrate, the operating frequency and the ratio of the semiconductor to insulator layer thicknesses. A strong interfacial polarisation, also known as the Maxwell–Wagner polarisation, is often responsible for the significant slow-down of the propagation velocity of MIS microstrip transmission lines. This phenomenon has been applied in the development of miniature delay lines exhibiting large electrical dimensions. In this paper we review most previously presented designs and we examine the effect of this polarization mechanism under various parameters. Finally, the presented micro-scale delay lines, exhibit comparable slowing factors with our predecessors at the cost of lower attenuation.
Juffali W, El-Imad J, Eftekhar A, et al., 2010, The WiNAM project: Neural data analysis with applications to epilespy, Biomedical Circuits and Systems Conference (BioCAS)
El Sharkawy MF, Georgiou P, Toumazou C, 2010, A Silicon Pancreatic Islet for the Treatment of Diabetes, International Symposium on Circuits and Systems Nano-Bio Circuit Fabrics and Systems (ISCAS 2010), Publisher: IEEE, Pages: 3136-3139, ISSN: 0271-4302
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- Citations: 3
Saremi-Yarahmadi S, Murphy OH, Toumazou C, 2010, RF Inductive Sensors for Detection of Change in the Ionic Strength and pH of Liquid Samples, International Symposium on Circuits and Systems Nano-Bio Circuit Fabrics and Systems (ISCAS 2010), Publisher: IEEE, Pages: 2279-2282, ISSN: 0271-4302
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- Citations: 1
Nikolic K, Loizu J, Degenaar P, et al., 2010, A stochastic model of the single photon response in Drosophila photoreceptors, Integrative Biology, Vol: 2, Pages: 354-370
We present a quantitative model for the phototransduction cascade in Drosophila photoreceptors. The process consists of four stages: (1) light absorption by Rhodopsin, (2) signal amplification phase mediated by a G-protein coupled cascade, (3) close/open state kinetics of the transient receptor potential (TRP) ion channels which regulate the ionic current in/out of the cell and (4) Ca regulated positive and negative feedbacks.The model successfully reproduces the experimental results for: single photon absorption "quantum bump" (QB), statistical features for QB (average shape, peak current average value and variance, the latency distribution, etc), arrestin mutant behaviour, low extracellular Ca2+ cases, etc. The TRP channel activity is modeled by a Monod-Wyman-Changeux (MWC) model for allosteric interaction, instead of using the usual ad hoc Hill equation. This approach allows for a plausible physical explanation how Ca/calmodulin regulate the protein activity. The cooperative nature of the TRP channel activation leads to "dark current" suppression at the output allowing for reliable detection of a single photon. Stochastic simulations were produced by using the standard rate equations combined with the Poisson distribution for generating random events from the forward and the reverse reaction rates. Noise is inherent to the system but appears to be crucial for producing such reliable responses in this complex, highly nonlinear system. The approach presented here may serve as a useful example how to treat complex cellular mechanisms underlying sensory processes.
Guven O, Geier F, Banks D, et al., 2010, An Open-Source Platform for the Development of Microcontroller Based Multi-Wavelength Oximetry, Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 282-285, ISSN: 2163-4025
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- Citations: 3
Georgiou P, Toumazou C, 2009, ISFET characteristics in CMOS and their application to weak inversion operation, SENSORS AND ACTUATORS B-CHEMICAL, Vol: 143, Pages: 211-217
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- Citations: 129
Oliver N, Georgiou P, Johnston D, et al., 2009, A benchtop closed-loop system controlled by a bio-inspired silicon implementation of the pancreatic beta cell., J Diabetes Sci Technol, Vol: 3, Pages: 1419-1424
UNLABELLED: The normal pancreatic beta-cell membrane depolarizes in response to increasing concentrations of glucose in a bursting pattern. At <7 mM (126 mg/dl), the cell is electrically silent. The bursting pulse width increases as glucose rises >7 mM (126 mg/dl) until a continuous train of bursting is seen at >25 mM (450 mg/dl). A bio-inspired silicon device has been developed using analogue electronics to implement membrane depolarization of the beta cell. The device is ultralow powered, miniaturized (5 x 5 mm), and produces a bursting output identical to that characterized in electrophysiological studies. OBJECTIVE: The goal of this study was to demonstrate the ability of silicon implementation of beta-cell electrophysiology to respond to a simulated glucose input and to drive an infusion pump in vitro. METHOD: The silicon device response to a current source was recorded at varying simulated glucose concentrations. Subsequently, the bursting response to a changing analyte concentration measured by an amperometric enzyme electrode was converted to a voltage, driving a syringe pump loaded with a 50-ml syringe containing water. RESULTS: Bursting responses are comparable to those recorded in electrophysiology. Silicon beta-cell implementation bursts with a pulse width proportional to concentration and is able to drive an infusion pump. CONCLUSION: This is the first in vitro demonstration of closed loop insulin delivery utilizing miniaturized silicon implementation of beta-cell physiology in analogue electronics.
Georgiou P, Toumazou C, 2009, ISFET threshold voltage programming in CMOS using hot-electron injection, ELECTRONICS LETTERS, Vol: 45, Pages: 1112-U17, ISSN: 0013-5194
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- Citations: 12
Huang Y, Drakakis EM, Toumazou C, 2009, A 30 pA/V-25 mu A/V linear CMOS channel-length-modulation OTA, Microelectronics Journal, Vol: 40, Pages: 1458-1465, ISSN: 0026-2692
Toumazou C, Cannillo F, 2009, Current Mode Logic Digital Circuits, US2009219054 (A1); GB20050021915 20051027; WO2006GB50360 20061027
A digital circuit comprises: a first arm including a first metal oxide semiconductor field effect transistor (M3) configured to act as a load device; a second arm including a second metal oxide semiconductor field effect transistor (M4) configured to act as a load device; and a switch (M1, M2) for selecting one of the first and second arms. Each of the first and second transistors (M3, M4) has a channel length of 100 nm or below and is biased to operate in the weak inversion regime. In an alternative circuit, each load device (M3, M4) has its bulk connected to its drain and is biased to operate in the weak inversion regime.
Cannillo F, Toumazou C, Lande TS, 2009, Nanopower Subthreshold MCML in Submicrometer CMOS Technology, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, Vol: 56, Pages: 1598-1611, ISSN: 1549-8328
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- Citations: 16
Cannillo F, Toumazou C, 2009, Subthreshold Parallel FM-to-Digital Δ-Σ Converter With Output-Bit-Stream Addition by Interleaving, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, Vol: 56, ISSN: 1549-8328
Vilches A, Sanni A, Toumazou C, 2009, Single coil pair transcutaneous energy and data transceiver for low power bio-implant use, ELECTRONICS LETTERS, Vol: 45, Pages: 727-U25, ISSN: 0013-5194
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- Citations: 3
Prodromakis T, Papavassiliou C, Konstantinidis G, et al., 2009, Application of gold nanodots for Maxwell-Wagner loss reduction, MICRO NANO LETT, Vol: 4, Pages: 80-83, ISSN: 1750-0443
Any element or mechanism that can cause a spatial variation of charge density can contribute to the dielectric susceptibility of a structure. Particularly, we focus on metal-insulator-semiconductor (MIS) structures that support interfacial polarisation. Since energy storage and dissipation are two aspects of the same phenomenon, the attainable large effective electric permittivity of such structures is accompanied by comparably large dielectric losses that prohibit practical application in monolithic-microwave integrated circuits (MMICs). The authors present a process technique for developing gold nanodots buried in the insulating medium that con. ne the electric field within the oxide layer, that is prohibiting E-field penetration to the substrate, which is rather lossy. Measured results demonstrate that the proposed structure exhibits an almost identical effective electric permittivity with a standard MIS, nonetheless the losses are decreased.
Chan WP, Premanode B, Toumazou C, 2009, 64 pH-ISFET averaging array employing global negative current feedback, ELECTRONICS LETTERS, Vol: 45, Pages: 536-U16, ISSN: 0013-5194
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- Citations: 6
Prodromakis T, Georgiou P, Michelakis K, et al., 2009, Effect of Mobile Ionic-Charge on CMOS Based Ion-Sensitive Field-Effect Transistors (ISFETs), IEEE International Symposium on Circuits and Systems, Publisher: IEEE
Georgiou P, Toumazou C, 2009, Chemical log-domain filter, ELECTRONICS LETTERS, Vol: 45, Pages: 391-U73, ISSN: 0013-5194
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- Citations: 2
Oliver NS, Toumazou C, Cass AEG, et al., 2009, Glucose sensors: a review of current and emerging technology, DIABETIC MEDICINE, Vol: 26, Pages: 197-210, ISSN: 0742-3071
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- Citations: 384
Zoumpoulidis T, Prodromakis T, van Zeijl H, et al., 2009, Stretchable Array of ISFET Devices for Applications in Biomedical Imagers, IEEE Sensors Conference, Pages: 7-12
Nikolic K, Grossman N, Grubb M, et al., 2009, Photocycles of Channelrhodopsin-2, Photochemistry and Photobiology, Vol: 85, Pages: 400-411
Liu Y, Georgiou P, Constandinou TG, et al., 2009, An Auto-Offset-Removal circuit for chemical sensing based on the PG-ISFET, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 1165-1168
Georgiou P, Toumazou C, 2009, An adaptive CMOS-based PG-ISFET for pH sensing, IEEE International Symposium on Circuits and Systems (ISCAS 2009), Publisher: IEEE, Pages: 557-560, ISSN: 0271-4302
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- Citations: 10
Thanapitak S, Toumazou C, 2009, Towards a Bionic Chemical Synapse, IEEE International Symposium on Circuits and Systems (ISCAS 2009), Publisher: IEEE, Pages: 677-+, ISSN: 0271-4302
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- Citations: 1
Prodromakis T, Michelakis K, Zoumpoulidis T, et al., 2009, Biocompatible Encapsulation of CMOS based Chemical Sensors, IEEE Sensors Conference, Pages: 791-794
Wong W, Shepherd L, Georgiou P, et al., 2009, Towards ISFET based DNA logic for rapid nucleic acid detection, 8th IEEE Conference on Sensors, Publisher: IEEE, Pages: 1451-1454, ISSN: 1930-0395
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- Citations: 5
Degenaar P, Grossman N, Berlinguer-Palmini R, et al., 2009, Optoelectronic microarrays for Retinal Prosthesis, IEEE Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 185-188
Eberle W, Mecheri AS, Nguyen TKT, et al., 2009, Health-care electronics The market, the challenges, the progress, Design, Automation and Test in Europe Conference and Exhibition, Publisher: IEEE, Pages: 1030-+, ISSN: 1530-1591
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- Citations: 1
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