Electromigration in Nano-Interconnects: Determining Reliability Margins in Redundant Mesh Networks Using a Scalable Physical-Statistical Hybrid Paradigm.

This paper presents a hybrid modelling approach that combines physics-based electromigration modelling (PEM) and statistical methods to evaluate the electromigration (EM) limits of nano-interconnects in mesh networks. The approach, which is also compatible with standard Place and Route (P&R) tools and practises, takes into account the positive impact of network redundancy on EM current limits. The numerical simulations conducted in this study show that conventional methods underestimate the EM current limits of a power delivery network (PDN) unit-cell by 80% due to their lack of consideration for redundancy.

Deciphering mechanical regulation of chondrogenesis in fibrin-polyurethane composite scaffolds enriched with human mesenchymal stem cells: a dual computational and experimental approach.

Fibrin-polyurethane composite scaffolds support chondrogenesis of human mesenchymal stem cells (hMSCs) derived from bone marrow and due to their robust mechanical properties allow mechanical loading in dynamic bioreactors, which has been shown to increase the chondrogenic differentiation of MSCs through the transforming growth factor beta pathway. The aim of this study was to use the finite element method, mechanical testing, and dynamic in vitro cell culture experiments on hMSC-enriched fibrin-polyurethane composite scaffolds to quantitatively decipher the mechanoregulation of chondrogenesis within these constructs. The study identified compressive principal strains as the key regulator of chondrogenesis in the constructs.

A multi-scale mechanobiological model of in-stent restenosis: deciphering the role of matrix metalloproteinase and extracellular matrix changes.

Since their first introduction, stents have revolutionised the treatment of atherosclerosis; however, the development of in-stent restenosis still remains the Achilles' heel of stent deployment procedures. Computational modelling can be used as a means to model the biological response of arteries to different stent designs using mechanobiological models, whereby the mechanical environment may be used to dictate the growth and remodelling of vascular cells. Changes occurring within the arterial wall due to stent-induced mechanical injury, specifically changes within the extracellular matrix, have been postulated to be a major cause of activation of vascular smooth muscle cells and the subsequent development of in-stent restenosis.

A multiscale mechanobiological modelling framework using agent-based models and finite element analysis: application to vascular tissue engineering.

Computational models of mechanobiological systems have been widely used to provide insight into these systems and also to predict their behaviour. In this context, vascular tissue engineering benefits from further attention given the challenges involved in developing functional low calibre vascular grafts with long-term patency. In this study, a novel multiscale mechanobiological modelling framework is presented, which takes advantage of lattice-free agent-based models coupled with the finite element method to investigate the dynamics of VSMC growth in vascular tissue engineering scaffolds.

Simulation of a balloon expandable stent in a realistic coronary artery-Determination of the optimum modelling strategy.

Computational models of stent deployment in arteries have been widely used to shed light on various aspects of stent design and optimisation. In this context, modelling of balloon expandable stents has proved challenging due to the complex mechanics of balloon-stent interaction and the difficulties involved in creating folded balloon geometries. In this study, a method to create a folded balloon model is presented and utilised to numerically model the accurate deployment of a stent in a realistic geometry of an atherosclerotic human coronary artery.

Determination of the influence of stent strut thickness using the finite element method: implications for vascular injury and in-stent restenosis.

Many clinical studies, including the ISAR-STEREO trial, have identified stent strut thickness as an independent predictor of in-stent restenosis where thinner struts result in lower restenosis than thicker struts. The aim of this study was to more conclusively identify the mechanical stimulus for in-stent restenosis using results from such clinical trials as the ISAR-STEREO trial. The mechanical environment in arteries stented with thin and thicker strut stents was investigated using numerical modelling techniques.