Emanuele Luigi Carniel

Replicating the nonlinear, strain‐dependent mechanics of soft biological tissues remains a central challenge in scaffold engineering, implantable devices and tissue‐mimicking phantom development. Current approaches lack a systematic, experimentally validated framework that quantitatively links unit cell characteristics to macroscopic mechanical response across clinically relevant stiffness ranges. Here, we introduce a geometry‐driven design strategy for 3D‐printed adipose‐inspired soft metamaterials, systematically varying unit cell diameter, shell thickness, orientation angle, and base material across multiple architectures. Compression experiments reveal that shell thickness governs initial stiffness and buckling onset, cell diameter controls the extent of the progressive instability plateau, and orientation angle switches the deformation mode from instability‐driven buckling to progressive compaction. Finite element simulations capture these mechanisms quantitatively, while a multivariate regression model predicts effective modulus, buckling stress, and energy absorption (R ² _adj > 0.86). The resulting design space spans elastic moduli from units to hundreds of kPa, covering the mechanical ranges of multiple soft biological tissues, demonstrating that a single geometric framework can be systematically tuned to target diverse soft‐tissue mechanical environments. This integrated experimental–computational–statistical platform establishes a mechanistic and geometry‐driven design foundation that can inform the rational development of programmable soft metamaterials for regenerative scaffolds, tissue‐mimicking phantoms, and soft implantable devices.

This study presents a comprehensive analytical investigation of linear viscoelastic behavior based on the classical Zener model and its generalized extension. Closed-form expressions are derived for key mechanical quantities, such as stress, tangent stiffness, hysteresis area, complex modulus, relaxation modulus, and creep modulus, under typical loading conditions, including constant strain rate, sinusoidal cyclic loading, stress relaxation, and creep. Particular attention is given to energy-dissipation phenomena, with formulations that elucidate the relationships between measurable mechanical responses and the underlying constitutive parameters. Notably, under cyclic loading, the analysis reveals linear correlations between the relaxation time and the time period corresponding to maximum energy dissipation. A linear extrapolation technique is also proposed to identify viscous parameters from stress-relaxation or creep data. These findings provide a practical reference for interpreting experimental results and support parameter estimation through analytical or computational approaches. Overall, this work offers a structured and interpretable framework for viscoelastic modeling, complementing numerical methods and enhancing the physical understanding of time-dependent behavior in polymers and time-dependent materials.

Objectives: To analyse and compare the functionality of extraluminal and intraluminal artificial urinary sphincters (AUSs), an in silico procedure has been defined and applied. Design and reliability assessments of the AUS are typically performed using a clinical approach, which does not provide data on mechanical stimulation of urethral tissues. Mechanical stimulation may determine tissue degeneration, such as urethral atrophy or erosion, the main causes of AUS failure. In silico techniques can provide a quantitative description of stress and strain fields due to the interaction between tissues and AUS and allow investigating an extremely large number of situations, considering different configurations of AUS and urethra.Materials and Methods: Computational investigations were carried out to evaluate the mechanical reliability of the main extraluminal and intraluminal AUS, AMS 800 and Relief. The lower urinary tract was modelled based on previous experiments. The AUS models took into account the main components that interact with biological tissues. Urethra and AUS models were coupled and used to investigate mechanical stimulation of urethral tissues.Results: In silico simulations provide quantitative information about the mechanical stimulation of urethral tissue, such as compressive strain and stress and hydrostatic pressure, due to interaction with the AUS. Such mechanical quantities allow a comparison of reliability between extraluminal and intraluminal devices.Conclusions: The activities define and demonstrate the effectiveness of a novel in silico approach to the design and reliability assessment of AUS devices, increasing the investigative possibilities and reducing the time, ethical and economic costs.

The relatively recent adoption of Endoscopic Sleeve Gastroplasty (ESG) amongst obese patients has gained approval within the surgical community due to its notable benefits, including significant weight loss, safety, feasibility, repeatability, and potential reversibility. However, despite its promising clinical outcomes and reduced invasiveness, there is still a lack of standardised procedures for performing ESG. Multiple suture patterns and stitching methods have been proposed over time, yet rational tools to quantify and compare their effects on gastric tissues are absent. To address this gap, this study proposed a computational approach. The research involved a case study analyzing three distinct suture patterns (C-shaped, U-shaped and Z-shaped) using a patient-specific computational stomach model generated from magnetic resonance imaging. Simulations mimicked food intake by placing wire features in the intragastric cavity to replicate sutures, followed by applying a linearly increasing internal pressure up to 15 mmHg. The outcomes facilitated comparisons between suture configurations based on pressure–volume behaviours and the distribution of maximum stress on biological tissues, revealing the U-shaped as the more effective in terms of volume reduction, even if with reduced elongation strains and increased tissues stresses, whereas the Z-shaped is responsible of the greatest stomach shortness after ESG. In summary, computational biomechanics methods serve as potent tools in clinical and surgical settings, offering insights into aspects that are challenging to explore in vivo, such as tissue elongation and stress. These methods allow for mechanical comparisons between different configurations, although they might not encompass crucial clinical outcomes.