Voxel-based simulation approach for molecular communications via diffusion

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Molecular communications via diffusion (MCvD) systems are easily simulated for micro-scale topologies and applications. On the other hand, due to the high path loss, there is a need for the emission of a very large number of molecules to have a detectable signal for the macro-scale topologies. Therefore, the simulation of macro-scale MCvD systems or applications has its own challenges. In this work, a voxel-based simulator for MCvD is proposed and analyzed. The proposed simulator is able to consider a very large amount of molecules since it does not track every molecule, instead it simulates the aggregate behavior. We assess the correctness of such a simulation approach through comparative studies with a particle-based (i.e., per-molecule) simulation. We present the effect of voxel side-length on the modeling accuracy and devise a framework for selecting the optimal voxel side-length for high-accuracy simulations.Peer ReviewedPreprin

Impact of receiver reaction mechanisms on the performance of molecular communication networks

In a molecular communication network, transmitters and receivers communicate by using signalling molecules. At the receivers, the signalling molecules react, via a chain of chemical reactions, to produce output molecules. The counts of output molecules over time is considered to be the output signal of the receiver. This output signal is used to detect the presence of signalling molecules at the receiver. The output signal is noisy due to the stochastic nature of diffusion and chemical reactions. The aim of this paper is to characterise the properties of the output signals for two types of receivers, which are based on two different types of reaction mechanisms. We derive analytical expressions for the mean, variance and frequency properties of these two types of receivers. These expressions allow us to study the properties of these two types of receivers. In addition, our model allows us to study the effect of the diffusibility of the receiver membrane on the performance of the receivers

Extended master equation models for molecular communication networks

We consider molecular communication networks consisting of transmitters and receivers distributed in a fluidic medium. In such networks, a transmitter sends one or more signalling molecules, which are diffused over the medium, to the receiver to realise the communication. In order to be able to engineer synthetic molecular communication networks, mathematical models for these networks are required. This paper proposes a new stochastic model for molecular communication networks called reaction-diffusion master equation with exogenous input (RDMEX). The key idea behind RDMEX is to model the transmitters as time series of signalling molecule counts, while diffusion in the medium and chemical reactions at the receivers are modelled as Markov processes using master equation. An advantage of RDMEX is that it can readily be used to model molecular communication networks with multiple transmitters and receivers. For the case where the reaction kinetics at the receivers is linear, we show how RDMEX can be used to determine the mean and covariance of the receiver output signals, and derive closed-form expressions for the mean receiver output signal of the RDMEX model. These closed-form expressions reveal that the output signal of a receiver can be affected by the presence of other receivers. Numerical examples are provided to demonstrate the properties of the model.Comment: IEEE Transactions on Nanobioscience, 201

Simulating underwater molecular propagation signal

Molecular Communication (MC) is a relatively new interdisciplinary research paradigm that is related to the field of: communications, nanotechnology, biotechnology, fluid dynamics, and chemical engineering. In MC, molecules are utilized to convey information which can be observed in nature (e.g., quorum sensing between bacteria at the micro-scales and pheromone-based communication at the macro-scales in both air and water environments).A new approach for Molecular Communication via Diffusion (MCvD), voxel-based simulations, is proposed and analyzed. Optimum voxel length relation with environment parameters is studied.Un nuevo método para la Comunicación Molecular via Difusión (MCvD), simulaciones basada en voxel, es propuesta y analizada. La longitud óptima para los voxel y su relación con los parámetros del entorno es estudiada.A new approach for Molecular Communication via Diffusion (MCvD), voxel-based simulations, is proposed and analyzed. Optimum voxel length relation with environment parameters is studied

Challenges and limits of mechanical stability in 3D direct laser writing

Direct laser writing is an effective technique for fabrication of complex 3D polymer networks using ultrashort laser pulses. Practically, it remains a challenge to design and fabricate high performance materials with different functions that possess a combination of high strength, substantial ductility, and tailored functionality, in particular for small feature sizes. To date, it is difficult to obtain a time-resolved microscopic picture of the printing process in operando. To close this gap, we herewith present a molecular dynamics simulation approach to model direct laser writing and investigate the effect of writing condition and aspect ratio on the mechanical properties of the printed polymer network. We show that writing conditions provide a possibility to tune the mechanical properties and an optimum writing condition can be applied to fabricate structures with improved mechanical properties. We reveal that beyond the writing parameters, aspect ratio plays an important role to tune the stiffness of the printed structures