Simone Morganti
@unipv.it
Senior Researcher; Department of Electrical, Computer, and Biomedical Engineering
University of Pavia
RESEARCH INTERESTS
finite elements
isogeometric analysis
additive manufacturing
computer simulations
cardiovascular mechanics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Paolo Iaccarino, Elvira Maresca, Simone Morganti, Ferdinando Auricchio, and Ernesto Di Maio
Wiley
The adoption of Nature‐inspired strategies to improve materials has fostered the introduction of cavities. But how to mass‐produce structures in which a complex architecture of cavities is point‐to‐point fine‐tuned to the local and global application requirements? To this aim, we herein report the use of a procedure based on topology optimization and gas foaming. As an example case, a polymeric foamed beam whose density map is optimized in 3D for three‐point bending was designed and produced by gas foaming a purpose‐designed preform. The preform was produced with polypropylene and by a high pressure autoclave with as blowing agent. Optical and scanning electron microscopy as well as X‐ray microscopy were used to analyze the 3D optimized foamed structures and showed the effectiveness of the foaming design protocol in producing the FEM‐optimized structures. A remarkable two‐fold increase in the stiffness of the optimized structures was measured with respect to that of the uniformly foamed counterpart with equal overall mass. With the use of a single recyclable material in a single processing step, this method allows one to conceive the mass production of optimized, therefore more sustainable, plastic parts.This article is protected by copyright. All rights reserved.
L. Airoldi, R. Brucculeri, P. Baldini, S. Morganti, M. Actis Grande, F. S. Gobber, F. Auricchio, and U. Anselmi-Tamburini
Springer Science and Business Media LLC
AbstractIn this paper, we propose a modified material jetting technology based on a piezoelectric-driven powder deposition, hence direct powder deposition (DPD), combined with pressure-assisted rapid sintering. This is a new approach toward the rapid production of metal and ceramic materials with complex geometries. The combined deposition of two loose powders within the same container, layer by layer, allows realizing complex shapes without the use of any binder or dispersing medium. The resulting green sample is then sintered by field assisted sintering (FAST) or spark plasma sintering (SPS) operating in a pseudo-isostatic mode. This combination of DPD and FAST/SPS allows great versatility, as it can be extended to a wide range of materials and composites without any significant modification of the setup. Moreover, the use of FAST/SPS densification allows the realization of fully sintered samples in less than one hour.
Sandipan Chattaraj, Michele Torre, Constanze Kalcher, Alexander Stukowski, Simone Morganti, Alessandro Reali, and Francesco Silvio Pasqualini
AIP Publishing
Modeling multiscale mechanics in shape-shifting engineered tissues, such as organoids and organs-on-chip, is both important and challenging. In fact, it is difficult to model relevant tissue-level large non-linear deformations mediated by discrete cell-level behaviors, such as migration and proliferation. One approach to solve this problem is subcellular element modeling (SEM), where ensembles of coarse-grained particles interacting via empirically defined potentials are used to model individual cells while preserving cell rheology. However, an explicit treatment of multiscale mechanics in SEM was missing. Here, we incorporated analyses and visualizations of particle level stress and strain in the open-source software SEM++ to create a new framework that we call subcellular element modeling and mechanics or SEM2. To demonstrate SEM2, we provide a detailed mechanics treatment of classical SEM simulations including single-cell creep, migration, and proliferation. We also introduce an additional force to control nuclear positioning during migration and proliferation. Finally, we show how SEM2 can be used to model proliferation in engineered cell culture platforms such as organoids and organs-on-chip. For every scenario, we present the analysis of cell emergent behaviors as offered by SEM++ and examples of stress or strain distributions that are possible with SEM2. Throughout the study, we only used first-principles literature values or parametric studies, so we left to the Discussion a qualitative comparison of our insights with recently published results. The code for SEM2 is available on GitHub at https://github.com/Synthetic-Physiology-Lab/sem2.
Michele Torre, Simone Morganti, Francesco S. Pasqualini, and Alessandro Reali
AIP Publishing
In this paper, we review a powerful methodology to solve complex numerical simulations, known as isogeometric analysis, with a focus on applications to the biophysical modeling of the heart. We focus on the hemodynamics, modeling of the valves, cardiac tissue mechanics, and on the simulation of medical devices and treatments. For every topic, we provide an overview of the methods employed to solve the specific numerical issue entailed by the simulation. We try to cover the complete process, starting from the creation of the geometrical model up to the analysis and post-processing, highlighting the advantages and disadvantages of the methodology.
Pasquale Totaro, Simone Morganti, Ferdinando Auricchio, and Stefano Pelenghi
Elsevier BV
Michele Torre, Simone Morganti, Alessandro Nitti, Marco D. de Tullio, Francesco S. Pasqualini, and Alessandro Reali
Elsevier BV
Lorenzo Airoldi, Riccardo Brucculeri, Primo Baldini, Francesco Pini, Barbara Vigani, Silvia Rossi, Ferdinando Auricchio, Umberto Anselmi-Tamburini, and Simone Morganti
Mary Ann Liebert Inc
Copper was manufactured by using a low-cost 3D printing device and copper oxide water-based colloids. The proposed method avoids the use of toxic volatile solvents (used in metal-based robocasting), adopting copper oxide as a precursor of copper metal due to its lower cost and higher chemical stability. The appropriate rheological properties of the colloids have been obtained through the addition of poly-ethylene oxide-co-polypropylene-co-polyethylene oxide copolymer (Pluronic P123) and poly-acrylic acid to the suspension of the oxide in water. Mixing of the components of the colloidal suspension was performed with the same syringes used for the extrusion, avoiding any material waste. The low-temperature transition of water solutions of P123 is used to facilitate the homogenization of the colloid. The copper oxide is then converted to copper metal through a reductive sintering process, performed at 1000°C for a few hours in an atmosphere of Ar-10%H2. This approach allows the obtainment of porous copper objects (up to 20%) while retaining good mechanical properties. It could be beneficial for many applications, for example current collectors in lithium batteries.
Michele Torre, Simone Morganti, Francesco S. Pasqualini, Alexander Düster, and Alessandro Reali
Elsevier BV
Alessia Cannatà, Simona Di Meo, Giulia Matrone, Simone Morganti, and Marco Pasian
IEEE
Multimodal tissue-mimicking breast phantoms represent a useful instrument to validate the experimental imaging systems, as biological samples are not always available for the testing. In the context of cancer detection, multimodal imaging approaches are gaining increasing interest as they could provide complementary data about the investigated tissues. The aim of this work is to provide a brief review on the characterization of dielectric, mechanical and acoustic properties of breast phantoms and to prove that it is possible to design a tissue-mimicking material able to emulate different physical properties (i.e., real and imaginary part of the dielectric permittivity, Young’s modulus, ultrasound wave speed and attenuation) of the corresponding human tissues.
Riccardo Gorla, Omar A. Oliva, Enrico Poletti, Alice Finotello, Simone Morganti, Jessica Zannoni, Mauro Agnifili, Marta Barletta, Mattia Squillace, Enrico Criscione,et al.
IMR Press
S. Di Meo, Alessia Cannatà, S. Morganti, G. Matrone and M. Pasian
Objective. In this paper, we focus on the dielectric and mechanical characterization of tissue-mimicking breast phantoms. Approach. Starting from recipes previously proposed by our research group, based on easy-to-handle, cheap and safe components (i.e. sunflower oil, deionized water, dishwashing liquid and gelatin), we produced and tested, both dielectrically and mechanically, more than 100 samples. The dielectric properties were measured from 500 MHz to 14 GHz, the Cole–Cole parameters were derived to describe the dielectric behaviour in a broader frequency range, and the results were compared with dielectric properties of human breast ex vivo tissues up to 50 GHz. The macroscale mechanical properties were measured by means of unconfined compression tests, and the impact of the experimental conditions (i.e. preload and test speed) on the measured Young’s moduli was analysed. In addition, the mechanical contrast between healthy- and malignant-tissue-like phantoms was evaluated. Main results. The results agree with the literature in the cases in which the experimental conditions are known, demonstrating the possibility to fabricate phantoms able to mimic both dielectric and mechanical properties of breast tissues. Significance. In this work, for the first time, a range of materials reproducing all the categories of breast tissues were experimentally characterized, both from a dielectric and mechanical point of view. A large range of frequency were considered for the dielectric measurements and several combinations of experimental conditions were investigated in the context of the mechanical characterization. The proposed results can be useful in the design and testing of complementary or supplementary techniques for breast cancer detection based on micro/millimetre-waves, possibly in connection with other imaging modalities.
Stefania Marconi, Massimo Carraturo, Gianluca Alaimo, Simone Morganti, Giulia Scalet, Michele Conti, Alessandro Reali, and Ferdinando Auricchio
Springer International Publishing
Mauro Murer, Giovanni Formica, Franco Milicchio, Simone Morganti, and Ferdinando Auricchio
Springer Science and Business Media LLC
AbstractWe present a Computational Fluid Dynamics (CFD) framework for the numerical simulation of the Laser Metal Deposition (LMD) process in 3D printing. Such a framework, comprehensive of both numerical formulations and solvers, aims at providing a sufficiently exhaustive scenario of the process, where the carrier gas, modeled as an Eulerian incompressible fluid, transports metal powders, tracked as Lagrangian discrete particles, within the 3D printing chamber. On the basis of heat sources coming from the laser beam and the heated substrate, the particle model is developed to interact with the carrier gas also by heat transfer and to evolve in a melted phase according to a growth law of the particle liquid mass fraction. Enhanced numerical solvers, characterized by a modified Newton-Raphson scheme and a parallel algorithm for tracking particles, are employed to obtain both efficiency and accuracy of the numerical strategy. In the perspective of investigating optimal design of the whole LMD process, we propose a sensitivity analysis specifically addressed to assess the influence of inflow rates, laser beams intensity, and nozzle channel geometry. Such a numerical campaign is performed with an in-house code developed with the open source Finite Element library, and publicly available online.
Michele Torre, Simone Morganti, Alessandro Nitti, Marco D. de Tullio, Francesco S. Pasqualini, and Alessandro Reali
Elsevier BV
Ferdinando Auricchio, Andrea Bacigalupo, Marco Lepidi, and Simone Morganti
Springer International Publishing
Alessia Cannata, Marco Pasian, Simona Di Meo, Giulia Matrone, and Simone Morganti
IEEE
The characterization of tissue-mimicking materials (TMMs) represents a critical step in the development and the testing of new imaging systems, involving different modalities based on millimeter (mm) and ultrasound (US) waves. In this work, two breast phantoms (i.e., a breast fat TMM and a tumor TMM) for multimodal imaging were produced and characterized from a dielectric, mechanical and acoustic point of view. The dielectric characterization was carried out in order to estimate the dielectric permittivity in the frequency range of 0.5-40 GHz. The mechanical measurements of these phantoms, instead, were performed to determine their Young's modulus at 5% strain with a pre-load of 0.2 N and a test speed of 0.5 mm/min. Then, the acoustic characterization was carried out too, in order to determine the US wave speed and attenuation in these TMMs. In this preliminary work, both the TMMs were found able to reproduce the abovementioned physical properties of the corresponding breast tissues.
Simona Di Meo, Alessia Cannata, Chiara Macchello, Simone Morganti, Marco Pasian, and Giulia Matrone
IEEE
Tissue-mimicking phantoms represent a key point for the development of biomedical systems for diagnostic imaging. In this paper, new recipes for tissue-mimicking breast phantoms are proposed and tested, both dielectrically and mechanically. Phantoms mimicking human breast neoplastic tissues are considered, as they are anatomically stiffer than the surrounding healthy tissues. In our recipes, only cheap, easy-to-manage and safe components are involved, and the performance of two solidifying agents (i.e., gelatin and agar) are evaluated both from a dielectric and a mechanical point of view. Dielectric measurements are performed from 500 MHz to 40 GHz, and mechanical tests are performed with the unconfined compression approach, using a preload of 0.2 N and a test speed of 0.5 mm/min. This analysis shows that agar is more suitable for the fabrication of stiffer phantoms as compared to gelatin.
Xuehuan He, Ferdinando Auricchio, Simone Morganti, and Jia Lu
Elsevier BV
A constitutive model that explicitly considers the gradual recruitment of collagen fibers is applied to investigate the uniaxial properties of human ascending aortic aneurysms. The model uses an effective stretch, which is a continuum scale kinematic variable measuring the true stretch of the tissue, to formulate the fiber stress. The constitutive equation contains two shape parameters characterizing the stochastic distribution of fiber waviness, and two elastic parameters accounting for, respectively, the elastic properties of ground substance and the straightened collagen fibers. The model is applied to 156 sets of uniaxial stress-stretch data obtained from 52 aneurysm samples. Major findings include (1) the uniaxial response can be well described by a quadratic strain energy function of the effective strain; (2) the ultimate stretches, when measured in terms of the effective stretch, are closely clustered around 1.1, in contrast to a much wider range in the original stretch; and (3) the ultimate stress correlates positively with the fiber stiffness. The age dependence and directional differences of constitutive parameters are also investigated. Results indicate that only the waviness depends strongly on age; no clear alterations occur in elastic parameters. Further, the fibers are wavier and stiffer in the circumferential direction than in the longitudinal direction. No other parameters exhibit significant direction difference. STATEMENT OF SIGNIFICANCE: We introduced a constitutive model which explicitly accounts for collagen fiber recruitment to investigate the uniaxial properties of human ascending aortic aneurysm tissues. Uniaxial response data from 156 specimens were considered in the study. It was found that the seemingly dissimilar response curves are, in fact, similar if we measure the deformation using an effective stretch which factors out the uncrimping deformation. The rupture stretches in terms of the effective stretch are closely packed around 1.1. And the stress-stretch curves collapse to a canonical curve after a transformation.
Alice Finotello, Riccardo Gorla, Nedy Brambilla, Francesco Bedogni, Ferdinando Auricchio, and Simone Morganti
Elsevier BV
Computational simulations of Transcatheter Aortic Valve Implantation (TAVI) have reached a high level of complexity and accuracy for the prediction of possible implantation scenarios during the decision-making process. However, when focusing on the prosthetic device, currently different devices are available on the market which not only have different geometries, but also different material properties. The present work focuses on the calibration of Nitinol constitutive parameters of four self-expandable devices starting from experimental radial force tests on the prosthetic samples. Beside providing optimal material properties for each specific device, we also perform a patient-specific simulation, comparing the results obtained using both "literature" and calibrated parameters with the aim of investigating the impact of metallic frame parameters choice on simulation results.
A. Cannata, S. Di Meo, S. Morganti, G. Matrone, and M. Pasian
IEEE
In this paper, the mechanical properties of tissue-mimicking phantoms, produced and dielectrically tested to mimic breast tissues, are presented. Testing on phantoms represents one of the key steps in the process of realization of several devices and, for this reason, the interest towards the realization of more and more realistic phantoms, not only from the dielectric point of view but also from the mechanical one, is growing. In this work, tissue-mimicking mixtures, based on the use of low-cost, safe and easy-to-handle materials (water, oil, gelatin and dishwashing liquid), produced for the realization of breast phantoms have been tested under different measurement conditions. Stress-strain curves are reported and a first comparison with Young's moduli in the literature of gelatin-based phantoms produced for the same anatomical district is presented. This work represents a first step in the realization of increasingly realistic tissue-mimicking mixtures, which, among other things, may pave the way for new combined imaging modalities.
Mauro Murer, Valentina Furlan, Giovanni Formica, Simone Morganti, Barbara Previtali, and Ferdinando Auricchio
Elsevier BV
Francesco Nappi, Laura Mazzocchi, Cristiano Spadaccio, David Attias, Irina Timofeva, Laurent Macron, Adelaide Iervolino, Simone Morganti, and Ferdinando Auricchio
MDPI AG
Aim: to investigate the factors implied in the development of postoperative complications in both self-expandable and balloon-expandable transcatheter heart valves by means of finite element analysis (FEA). Materials and methods: FEA was integrated into CT scans to investigate two cases of postoperative device failure for valve thrombosis after the successful implantation of a CoreValve and a Sapien 3 valve. Data were then compared with two patients who had undergone uncomplicated transcatheter heart valve replacement (TAVR) with the same types of valves. Results: Computational biomechanical modeling showed calcifications persisting after device expansion, not visible on the CT scan. These calcifications determined geometrical distortion and elliptical deformation of the valve predisposing to hemodynamic disturbances and potential thrombosis. Increased regional stress was also identified in correspondence to the areas of distortion with the associated paravalvular leak. Conclusion: the use of FEA as an adjunct to preoperative imaging might assist patient selection and procedure planning as well as help in the detection and prevention of TAVR complications.
Alice Finotello, Rodrigo M. Romarowski, Riccardo Gorla, Giovanni Bianchi, Francesco Bedogni, Ferdinando Auricchio, and Simone Morganti
Elsevier BV
OBJECTIVE
Transcatheter Aortic Valve Implantation (TAVI) is a consolidated procedure showing a low operative risk and excellent long-term outcomes in patients with aortic stenosis. Patients presenting a bicuspid aortic valve (BAV) often require valve replacement due to the highly calcific nature of the aortic leaflets. However, BAV patients have usually been contraindicated for TAVI due to their complex valve anatomy. The aim of this work was to compare the performance of devices featuring high conformability (HC) against those with high radial force (HRF).
METHODS
Four BAV patients undergoing TAVI were retrospectively selected. The aortic roots including the native leaflets and calcifications were reconstructed from pre-operative Computed Tomography scans. In each patient, both HC and HRF devices were virtually implanted using Finite Element Analysis simulations. After implantation, paravalvular orifice area, von Mises stress distribution, root contact area, and device eccentricity were calculated.
RESULTS
Simulations showed good agreement with intraoperative imaging. In 3 out of 4 patients, the HRF device resulted in a lower paravalvular area than the HC. Stress distribution was also more homogeneously distributed in the HRF group as compared with the HC group. Despite their lower adaptability, HRF devices showed consistently higher stent-root contact area.
CONCLUSION
HRF devices showed improved results with respect to HC valves after being deployed in BAV anatomies. We hypothesize that the ability to reshape the annulus is the major determinant of success in this subgroup of patients featuring highly calcified leaflets.
Ferdinando Auricchio, Michele Conti, Stefania Marconi, Simone Morganti, and Franca Scocozza
Elsevier
S. Morganti, F. Fahrendorf, L. De Lorenzis, J. A. Evans, T. J. R. Hughes, and A. Reali
Computers, Materials and Continua (Tech Science Press)