Journals:
S.Z. Denic, B. Basic, and C.D. Charalambous, J. Cheng, J.M. Wang, “Information Theoretic Modeling and Analysis for Global Interconnects with Process Variations,” IEEE Transactions on VLSI Systems, Vol. 19, No.3, pp.397-410, March 2011
Abstract
As the CMOS semiconductor technology enters nanometer regime, interconnect processes must be compatible with device roadmaps and meet manufacturing targets at the specified wafer size. The resulting ubiquitous process variations cause errors in data delivering through interconnects. This paper proposes an Information Theory based design method to accommodate process variations. Different from the traditional delay based design metric, the current approach uses achievable rate to relate interconnect designs directly to communication applications. More specifically, the data communication over a typical interconnect, a bus, subject to process variations (“uncertain” bus), is defined as a communication problem under uncertainty. A data rate, called the achievable rate, is computed for such a bus, which represents the lower bound on the maximal data rate attainable over the bus. When a data rate applied over the bus is smaller than the achievable data rate, a reliable communication can be guaranteed regardless of process variations, i.e., a bit error rate arbitrarily close to zero is achievable. A single communication strategy to combat the process variations is proposed whose code rate is equal to the computed achievable rate. The simulations show that the variations in the interconnect resistivity could have the most harmful effect regarding the achievable rate reduction. Also, the simulations illustrate the importance of taking into account bus parasitic parameters correlations when measuring the influence of the process variations on the achievable rates.
A. Kyprianou, N. Loucaides, N. Polydorides, G. E. Georghiou, C. D. Charalambous, and C. Doumanides, “Stochastic Control of NanoParticle Manipulation Using Electric Field,” International Journal of Nano Manufacturing, Vol.1, No.6, pages 751-761, 2007
Abstract
A simplified model is used to study the dynamics of a nanoparticle suspended in a fluid under Dielectrophoretic (DEP) force. The model considers the DEP force (considering only dipoles formed and not higher order polarisation) and the Brownian motion of the particle. Stochastic control and estimation methods are introduced to provide control action via DEP force that pushes the particle in a specific direction. The control action employed is based on alternating the polarity of the electric field that induces the force exerted on the particle. Despite the simplicity of the model, a sufficient insight into the nature of applying stochastic control techniques can be derived. Simulations are also presented to illustrate the proposed stochastic control techniques, by simulating the behaviour of the controlled nanoparticle system described by a stochastic differential equation driven by Brownian motion subject to optimal DEP force computed by solving an optimal stochastic control problem.
N. Loukaidis, G.E. Georghiou, C.D. Charalambous, ”Numerical Simulations of the Dielectrophoretic Concentration of DNA Particles and the Effect of AC Electroosmosis,’’ Journal of Physics: Conference Series, vol.61, pp.718-723, 2007
Abstract
The dielectrophoretic concentration of DNA particles suspended in a solution is investigated in a system of parallel electrodes, where the particles are attracted to the edges of the electrodes by positive dielectrophoresis. The AC electroosmotic motion of the fluid is also considered, as well as the diffusion of the particles, using the solution of the Smoluchowski equation. The results examine the effect of AC electroosmosis in steady state dielectrophoretic concentration of particles, by demonstrating that AC electroosmosis significantly reduces the dielectrophoretic concentration at the edges and moves the particles towards the electrode centres.
N. Polydorides and A. Kyprianou and C.D. Charalambous, ”Numerical Modeling for Atomic Force Microscopy Based Impedance Imaging,’’ Proceedings o the Institution of Mechanical Engineers, Part N: Journal of Nano-engineering and Nanosystems, Vol. 219, No.14, pages 147-156, 2005
Abstract
This paper is motivated by the pioneering work of O'Hayre et al. and of Kalinin and Bonnell who brought together the imaging modalities of atomic force microscopy (AFM) and electrical impedance spectroscopy. With the intention to assist in the further development of AFM-impedance imaging by enhancing its quantitative spatial resolution, a numerical model is provided on the basis of a finite element method which can be used to simulate the impedance measurements. The model facilitates the contact impedance at the interface between the tip of the atomic force microscope's cantilever and the upper surface of the sample. Based on this model, a formula is derived for the linearized sensitivity of the measurement as a spatial function that relates the value of electric potential recorded at the tip to the electrical properties of the sample underneath it. The performed numerical simulations suggest that the sensitivity functions of adjacently captured impedance measurements overlap, and this introduces linear dependences in the acquired data, ultimately reducing the spatial resolution of the reconstructed image.
Conferences:
A. Kyprianou, N. Loucaides, G. Georghiou, C.D. Charalambous, and C. Doumanides, “Stochastic Control of Nanoparticle Manipulation Using Electric Field,” in 4th International Symposium on Nanomanufacturing-ISNM 2006, pp. Massachusetts Institute of Technology, Boston, U.S.A., Basel, Nov.1-3, 2006
Abstract
A simplified model is used to study the dynamics of a nanoparticle suspended in a fluid under Dielectrophoretic (DEP) force. The model considers the DEP force (considering only dipoles formed and not higher order polarisation) and the Brownian motion of the particle. Stochastic control and estimation methods are introduced to provide control action via DEP force that pushes the particle in a specific direction. The control action employed is based on alternating the polarity of the electric field that induces the force exerted on the particle. Despite the simplicity of the model, a sufficient insight into the nature of applying stochastic control techniques can be derived. Simulations are also presented to illustrate the proposed stochastic control techniques, by simulating the behaviour of the controlled nanoparticle system described by a stochastic differential equation driven by Brownian motion subject to optimal DEP force computed by solving an optimal stochastic control problem.
N. Loucaides, G. Georghiou, and C.D. Charalambous, "Combined Dielectrophoretic and Electro hydrodynamic Manipulation of Nanoparticles,” in 4th International Symposium on Nano-manufacturing-ISNM 2006, pp. Massachusetts Institute of Technology, Boston, U.S.A., Basel, Nov.1-3, 2006
N. Loucaides and G. Georghiou and C.D. Charalambous, “Numerical Simulation of the Dielectrophoretic Concentration of DNA Particles and the Effects of AC Electroosmosis,” in International Conference on Nanoscience and Technology (ICNT), pp. Basel, Switzerland, July 30-August, 2006
Abstract
The dielectrophoretic concentration of DNA particles suspended in a solution is investigated in a system of parallel electrodes, where the particles are attracted to the edges of the electrodes by positive dielectrophoresis. The AC electroosmotic motion of the fluid is also considered, as well as the diffusion of the particles, using the solution of the Smoluchowski equation. The results examine the effect of AC electroosmosis in steady state dielectrophoretic concentration of particles, by demonstrating that AC electroosmosis significantly reduces the dielectrophoretic concentration at the edges and moves the particles towards the electrode centres.
N. Polydorides and C.D. Charalambous and A. Kyprianou, “Impedance Imaging Using Atomic Force Microscopy,” in 3rd International Symposium on Nanomanufacturing, pp. Cyprus, November 3-5, 2005
N. Loucaides and G. Georghiou and C.D. Charalambous, “Manipulation of Nano-Particles by Electronic Methods: Model Development,” in 3rd International Symposium on Nanomanufacturing, pp. Cyprus, November 3-5, 2005
