Institute of Fundamental Technological Research

Kędziorski P., Skoratko A., Katzer J., Tysiąc P., Jagoda M., Zawidzki M., Harnessing low-cost LiDAR scanners for deformation assessment of 3D-printed concrete-plastic columns with cross-sections based on fractals after critical compressive loading, MEASUREMENT, ISSN: 0263-2241, DOI: 10.1016/j.measurement.2025.117015, Vol.249, pp.1-16, 2025

Abstract:
This article aims to explore the potential of using low-cost devices (iPhone and iPad) equipped with LiDAR scanners in the context of measuring the volume of concrete-plastic specimens with complex shapes. The goal was to assess whether these tools can support or even replace traditional metrology methods. For the purpose of the research program concrete-plastic columns with very complex cross-sections (based on different fractals) were harnessed. The research team was focused on analyzing the potential of using this technology to measure the volume of concrete-plastic structural elements created with the help of 3D printing. The tests were conducted under laboratory conditions. The effectiveness of the proposed approach was compared with results obtained using photogrammetry. The challenges of measurement accuracy, the impact of specimen shape, the impact of material and needed optimization of post-processing on the achieved results were also discussed.

Keywords:
3-D printing, LiDAR, Scanning, Fractals, Concrete

Deshpande S., Rappel H., Hobbs M., Bordas S., Lengiewicz J.A., Gaussian process regression + deep neural network autoencoder for probabilistic surrogate modeling in nonlinear mechanics of solids, COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING, ISSN: 0045-7825, DOI: 10.1016/j.cma.2025.117790, Vol.437, No.117790, pp.1-17, 2025

Abstract:
Many real-world applications demand accurate and fast predictions, as well as reliable uncertainty estimates. However, quantifying uncertainty on high-dimensional predictions is still a severely under-investigated problem, especially when input–output relationships are non-linear. To handle this problem, the present work introduces an innovative approach that combines autoencoder deep neural networks with the probabilistic regression capabilities of Gaussian processes. The autoencoder provides a low-dimensional representation of the solution space, while the Gaussian process is a Bayesian method that provides a probabilistic mapping between the low-dimensional inputs and outputs. We validate the proposed framework for its application to surrogate modeling of non-linear finite element simulations. Our findings highlight that the proposed framework is computationally efficient as well as accurate in predicting non-linear deformations of solid bodies subjected to external forces, all the while providing insightful uncertainty assessments.

Keywords:
Surrogate modeling,Deep neural networks,Gaussian proces,Autoencoders,Uncertainty quantification,Finite element method

Nwaji N., Fikadu B. B., Osial M., Warczak M., Moazzami Goudarzi Z., Gniadek M., Asgaran S., Lee J., Giersig M., Advanced Functional NiCo 2 S4 @CoMo2 S4 Heterojunction Couple as Electrode for Hydrogen Production via Energy-Saving Urea Oxidation, Small, ISSN: 1613-6810, DOI: 10.1002/smll.202410848, Vol.2410848, pp.1-13, 2025

Abstract:
The urea oxidation reaction (UOR) is characterized by a lower overpotential compared to the oxygen evolution reaction (OER) during electrolysis, which facilitates the hydrogen evolution reaction (HER) at the cathode. Charge
distribution, which can be modulated by the introduction of a heterostructure, plays a key role in enhancing the adsorption and cleavage of chemical groups within urea molecules. Herein, a facile all-room temperature synthesis of functional heterojunction NiCo2 S4 /CoMo 2 S4 grown on carbon cloth (CC) is presented, and the as-prepared electrode served as a catalyst for simultaneous hydrogen evolution and urea oxidation reaction. The Density
Functional Theory (DFT) study reveals spontaneous transfer of charge at the heterointerface of NiCo 2 S4 /CoMo 2 S4 , which triggers the formation of localized electrophilic/nucleophilic regions and facilitates the adsorption of electron donating/electron withdrawing group in urea molecules during the UOR. The NiCo2 S4 /CoMo 2 S4 // NiCo 2 S4 /CoMo 2 S4 electrode pair required only a cell voltage of 1.17 and 1.18 V to deliver a current density of 10 and 100 mA cm−2 respectively in urea electrolysis cell and display very good stability. Tests performed in real urine samples show similar catalytic performance to urea electrolytes, making the work one of the best transition
metal-based catalysts for UOR applications, promising both efficient hydrogen production and urea decomposition.

Liu S., Wu J., Teng F., He S., Yuan X., Stupkiewicz S., Wang Y., Effect of surface adhesion characteristics on stick-slip mechanism of flexible film/substrate bilayer structure: Multiscale insight, TRIBOLOGY INTERNATIONAL, ISSN: 0301-679X, DOI: 10.1016/j.triboint.2025.110520, Vol.204, pp.110520-1-16, 2025

Abstract:
The key to tactile sensors' sliding perception is the stick-slip modulation of the soft material through surface design. Herein, in-situ sliding tests were conducted on polydimethylsiloxane (PDMS) film/substrate bilayer structures (PF/SBS) with three surface adhesion characteristics tailored by crosslinking degrees of PDMS film. Microscopic damage mechanisms during Schallamach wave propagation were analyzed using mixed-mode cohesive contact models. Intermolecular interaction mechanisms at microscopic crack tips were also explored using PDMS-Silica (SiO2) molecular models with varying PDMS crosslinking degrees. The Schallamach waves and tangential force strongly depended on the crosslinking degree of PDMS film. The varying effects of crosslinking degree on normal and tangential separation mechanisms lead to a transition in Schallamach wave damage from mixed mode to Mode II during propagation.

Keywords:
Stick-slip,Film/substrate bilayer structures,Cohesive contact model,Intermolecular interaction

Zakrzewska A., Kosik-Kozioł A., Zargarian S., Zanoni M., Gualandi C., Lanzi M., Pierini F., Lemon Juice-Infused PVA Nanofibers for the Development of Sustainable Antioxidant and Antibacterial Electrospun Hydrogel Biomaterials, BIOMACROMOLECULES, ISSN: 1525-7797, DOI: 10.1021/acs.biomac.4c01466, Vol.26, No.1, pp.654-669, 2025

Abstract:
Cross-linking bonds adjacent polymer chains into a three-dimensional network. Cross-linked poly(vinyl alcohol) (PVA) turns into a hydrogel, insoluble structure exhibiting outstanding sorption properties. As an electrospinnable polymer, PVA enables the creation of nanofibrous hydrogels resembling biological tissues, thus ideal for nature-inspired platforms. PVA properties are easily adjustable through additives and an appropriate cross-linking method. Drawing inspiration from environmentally safe approaches, this work developed a new “green” method of low-temperature PVA cross-linking. Nanofibers were electrospun from a precursor solution of PVA dissolved in fresh lemon juice, stabilized by heating at 60 °C for 7 days, and thoroughly characterized. The obtained nanoplatform demonstrated long-term stability and enhanced mechanical properties. Its biocompatibility was confirmed, and its antibacterial and health-promoting effects were attributed to lemon juice-rich in vitamin C, a potent antioxidant with anti-inflammatory properties. The developed system has future potential for use in the biomedical engineering field as a dressing accelerating wound healing.

Postek E. W., Sadowski T., Guhathakurta J., Steel Ball Impact on SiC/AlSi12 Interpenetrated Composite by Peridynamics, Materials, ISSN: 1996-1944, DOI: 10.3390/ma18020290, Vol.18, No.290, pp.1-25, 2025

Abstract:
Silicon carbide and an aluminum alloy (SiC/AlSi12) composite are obtained during the pressurized casting process of the aluminum alloy into the SiC foam. The foam acts as a high-stiffness skeleton that strengthens the aluminum alloy matrix. The goal of the paper is to describe the behavior of the material, considering its internal structure. The composite’s structure is obtained by using X-ray computing tomography. The thorough computer tomography analysis allows for the high-precision identification of the shape and distribution of the pores in the matrix. The computational model prepared in the framework of the peridynamics method takes into account the pores and their shape. The pores in the structure appeared in the fabrication process. The impact of a steel ball is studied employing the peridynamics method. The sample without any porosity and a porous one were considered during the analyses. It has been found that the porosity of the matrix influences the plastic strain development, but the damage parameter in the skeleton is not affected significantly. The damage advancement in the skeleton during the process is practically identical in both cases. The equivalent plastic strain field is much smoother in a non-porous matrix than in a porous one. The porous matrix has high equivalent
plastic strain concentrations, much higher than the non-porous matrix. The shape of the sample is affected by the porosity of the matrix. The sample with a porous matrix tends to fragment, and it shows a tendency towards spallation when in close contact to the surface with the base.

Keywords:
interpenetrated composite, impact, damage, perydynamics

Fathalian M., Darban H., Postek E. W., Atomistic insights into tensile damage of functionally Graded Al-SiC composites, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, ISSN: 0020-7403, DOI: 10.1016/j.ijmecsci.2025.110012, Vol.288, pp.110012-1-110012-16, 2025

Abstract:
The tensile behavior and damage mechanisms of functionally graded (FG) Al-SiC composites are systematically investigated using molecular dynamics (MD) simulations. A comprehensive set of large-scale MD simulations is conducted on FG composites composed of three layers reinforced with different volume fractions of randomly distributed three-dimensional SiC particles. This work introduces a novel approach by modeling the reinforcement ceramic as three-dimensional particles, thereby more accurately representing the FG composite microstructure. Predictions of the model for Young's moduli of composites align with experimental data from the literature. The yield and ultimate tensile strength are overestimated due to the high applied strain rates and idealized crystal structures used in the simulations, which lack common defects such as vacancies and dislocations. The model is utilized to study the influence of reinforcement particle shape, size, orientation, and distribution on the tensile and damage behavior of composites. The FG composites reinforced with cubic particles demonstrate lower yield and tensile strength than those with spherical particles, primarily due to the high-stress concentrations around the corners of the cubic reinforcements. Reducing the size of SiC particles enhances the elastic modulus, yield, and tensile strength of the FG composites. It is shown that the stiffness of the FG composites reinforced with rectangular prisms can be effectively tailored by changing the orientation of the reinforcements. When SiC rectangular prisms are aligned along the tensile direction, the resulting FG composites exhibit higher yield and tensile strength. This work offers fundamental atomistic insights that help design FG composites with better mechanical performance.

Zaszczyńska A., Marzena Z., Kołbuk-Konieczny D., Denis P., Gradys A., Sajkiewicz P., On the Structural and Biological Effects of Hydroxyapatite and Gold Nano-Scale Particles in Poly(Vinylidene Fluoride) Smart Scaffolds for Bone and Neural Tissue Engineering, Molecules, ISSN: 1420-3049, DOI: 10.3390/molecules30051041, Vol.30, No.5, pp.1041-1-32, 2025

Abstract:
Piezoelectric materials, due to their ability to generate an electric charge in response to mechanical deformation, are becoming increasingly attractive in the engineering of bone and neural tissues. This manuscript reports the effects of the addition of nanohydroxyapatite (nHA), introduction of gold nanoparticles (AuNPs) via sonochemical coating, and collector rotation speed on the formation of electroactive phases and biological properties in electrospun nanofiber scaffolds consisting of poly(vinylidene fluoride) (PVDF). FTIR, WAXS, DSC, and SEM results indicate that introduction of nHA increases the content of electroactive phases and fiber alignment. The collector rotational speed increases not only the fiber alignment but also the content of electroactive phases in PVDF and PVDF/nHA fibers. Increased fiber orientation and introduction of each of additives resulted in increased SFE and water uptake. In vitro tests conducted on MG-63 and hiPSC-NSC cells showed increased adhesion and cell proliferation. The results indicate that PVDF-based composites with nHA and AuNPs are promising candidates for the development of advanced scaffolds for bone and neural tissue engineering applications, combining electrical functionality and biological activity to support tissue regeneration.

Keywords:
scaffolds, tissue engineering, bone tissue engineering, smart medicine, biodegradable polymers, regenerative medicine, poly(vinylidene fluoride)

Maździarz M., Suitability of Available Interatomic Potentials for Sn to Model Its 2D Allotropes, Journal of Computational Chemistry, ISSN: 0192-8651, DOI: 10.1002/jcc.70032, Vol.46, No.2, pp.e70032-1-e70032-12, 2025

Abstract:
The suitability of a range of interatomic potentials for elemental tin was evaluated in order to identify an appropriate potential for modeling the stanene (2D tin) allotropes. Structural and mechanical features of the flat (F), low-buckled (LB), high-buckled (HB), full dumbbell (FD), trigonal dumbbell (TD), honeycomb dumbbell (HD), and large honeycomb dumbbell (LHD) monolayer tin (stanene) phases, were gained by means of the density functional theory (DFT) and molecular statics (MS) calculations with ten different Tersoff, modified embedded atom method (MEAM), and machine-learning-based (ML-IAP) interatomic potentials. A systematic quantitative comparison and discussion of the results is reported.

Keywords:
2D materials, DFT, interatomic potentials

Piotrzkowska-Wróblewska H. E., Bajkowski J. M., Dyniewicz B., Bajer C. I., Identification of a spatially distributed diffusion model for simulation of temporal cellular growth, JOURNAL OF BIOMECHANICS, ISSN: 0021-9290, DOI: 10.1016/j.jbiomech.2025.112581, Vol.182, pp.1-7, 2025

Abstract:
This study introduces a spatially distributed diffusion model based on a Navier–Stokes formulation with a pseudo-velocity field, providing a framework for modelling cellular growth dynamics within diseased tissues. Five coupled partial differential equations describe diseased cell development within a two-dimensional spatial domain over time. A pseudo-velocity field mimics biomarker concentration increasing over time and space, influencing tumour growth dynamics. An

Keywords:
Tumour growth, Cellular growth, Cancer, Navier–stokes, Diffusion, Finite element method

Sitek R., Bochenek K., Maj P., Marczak M., Żaba K., Kopeć M., Kaczmarczyk G., Kamiński J., Hot-Pressing of Ti-Al-N Multiphase Composite: Microstructure and Properties, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app15031341, Vol.15, No.1341, pp.1-15, 2025

Abstract:
This study focuses on the development and characterization of a bulk Ti-Al-N
multiphase composite enriched with BN addition and sintered through hot pressing. The
research aimed to create a material with optimized mechanical and corrosion-resistant
properties suitable for demanding industrial applications. The composite was synthesized using a powder metallurgy approach with a mixture of AlN, TiN, and BN powders, processed under a high temperature and pressure. Comprehensive analyses, including microstructural evaluation, hardness testing, X-ray tomography, and electrochemical corrosion assessments, were conducted. The results confirmed the formation of a multiphase microstructure consisting of TiN, Ti₂AlN and Ti₃AlN phases. The microstructure was uniform with minimal porosity, achieving a hardness within the range of 500–540 HV2. Electrochemical tests revealed the formation of a passive oxide layer that provided moderate corrosion resistance in chloride-rich environment. However, localized pitting corrosion was observed under extreme conditions. The study highlights the potential of a BN admixture to enhance mechanical and corrosion-resistant properties and suggests directions for further optimization in sintering processes and material formulations.

Keywords:
AlN-TiN(BN) composite,hot-pressing,μCT,corrosion resistance

Bernard T., Mikułowski G., Szara T., Dołasiński M., Jasiński T., Domino M., Aspect-related mechanical properties of the cortical bone in the third metacarpal bone of mares, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app15031593, Vol.15, No.1593, pp.---, 2025

Abstract:
Complete fractures of the third metacarpal bone (MC III) diaphysis pose a significant
clinical challenge, prompting advanced veterinary medicine to utilize constitutive and
biomechanical modeling to better understand bone behavior. This study aims to compare
the elastic modulus of the MC III cortical bone, supported by measurements of cortical
bone thickness and relative density, across the dorsal, lateral, medial, and palmar aspects of
the MC III, as well as to evaluate the cortical bone’s response to compressive forces applied
in different directions. Given the bone structure can exhibit sex-related differences, MC III
bones were isolated from six equine cadaver limbs collected exclusively from mares and
imaged using computed tomography (CT) to measure thickness and density. Cortical bone
samples were collected from the four aspects of the MC III and subjected to mechanical
testing followed by the elastic modulus calculation. Bone thickness and elastic modulus
varied across the MC III aspects. Thinner cortical bone on the palmar aspect coincided with
a lower sample reaction force-based elastic modulus in the externo-internal direction and a
lower axial compression force elastic modulus in the proximo-distal direction. Regardless
of the MC III aspect, the cortical bone demonstrated greater resistance to compressive forces
when loaded in the vertical plane than in the horizontal plane. The returning of different
values in mechanical tests depending on the direction of loading may be attributed to
the anisotropic behavior of the cortical bone, which may implicate the increased risk of
complete fractures of the MC III diaphysis due to a kick from another horse or a fall, rather
than from training or competition-related overload.

Keywords:
bone thickness, mechanical test, copression, bending, elastic modulus, equine

Dyniewicz B., Shillor M., Bajer C. I., Dynamic behavior of an extended Gao beam model including shear deformation, Nonlinear Analysis: Real World Applications, ISSN: 1468-1218, DOI: 10.1016/j.nonrwa.2025.104340, Vol.85, pp.1-14, 2025

Abstract:
This study develops a model of the dynamics of the extended 2D Gao beam and simulates it. Here, the static model studied by Dyniewicz, Shillor and Bajer (Meccanica, 2024), is modified by incorporating inertial terms to account for dynamic behavior. The beam model expands the 1D Gao beam, which can oscillate around a buckled position, and the Timoshenko beam, which factors in shear effects in the beam’s cross sections. The resulting model consists of two highly nonlinear wave equations, alongside specified initial and boundary conditions. A finite element method (FEM) algorithm is created and executed to analyze the system’s vibrations induced by a periodically oscillating longitudinal compressive force. The simulation results are discussed, highlighting the ways the initial conditions influence the solutions, which are graphically illustrated through phase portraits. From an engineering viewpoint, this thick Gao beam model is notable for its relative simplicity. Similarly to the Timoshenko beam model, it includes shear effects, yielding a wave-like equation of motion. Considerations of the shear are essential for accurately analyzing thicker beams, as traditional models that overlook them may fail to capture the true system behaviors. Consequently, this extended Gao model offers more realistic outcomes in dynamic scenarios.

Keywords:
Extended Gao beam, Dynamic oscillations, Vibrations about buckled state, Simulations

Rosowska J., Kaszewski J., Krajewski M., Małolepszy A., Witkowski B. S., Wachnicki Ł., Lev-Ivan B., Sybilski P., Godlewski M., Godlewski M., Growth of ZnO Nanoparticles Using Microwave Hydrothermal Method — Search for Defect-Free Particles, Nanomaterials, ISSN: 2079-4991, DOI: 10.3390/nano15030230, Vol.15, No.230, pp.1-21, 2025

Keywords:
zinc oxide (ZnO) nanoparticles, microwave hydrothermal method , microwave-assisted synthesis, near-band-edge (NBE) emission, deep-level emission (DLE), luminescent properties of ZnO, photoluminescence (PL), cathodoluminescence (CL), defect-related luminescence

Orthey A., Dieguez P., Makuta O., Remigiusz A., High-dimensional monitoring and the emergence of realism via multiple observers, Physical Review A, ISSN: 2469-9926, DOI: 10.1103/PhysRevA.111.012220, Vol.111, No.012220, pp.1-10, 2025

Abstract:
Correlation is the basic mechanism of every measurement model, as one never accesses the measured system directly. Instead, correlations are created, codifying information about the measurable property into the environment. Here, we address the problem of the emergence of physical reality from the quantum world by introducing a model that interpolates between weak and strong nonselective measurements for qudits. By utilizing Heisenberg-Weyl operators, our model suggests that independently of the interaction intensity between the system and the environment, full information about the observable of interest can always be obtained by making the system interact with many environmental qudits, following a quantum Darwinism framework.

Bajkowski J. M., Bajer C. I., Dyniewicz B., Bajkowski J., Leonowicz M., Performance of a vibration damper using a new compressible magnetorheological fluid with microspheres, SMART MATERIALS AND STRUCTURES, ISSN: 0964-1726, DOI: 10.1088/1361-665X/ad9cd7, Vol.34, pp.1-12, 2025

Abstract:
A novel magnetorheological (MR) fluid was synthesised by incorporating compressible, nonmagnetic polyurethane microspheres and ferromagnetic iron particles into polyalphaolefin oil. This innovative composition reduces sedimentation, enhances compressibility beyond that of conventional MR fluids, and achieves comparable yield stress with a lower concentration of iron particles. The new MR fluid was evaluated in a prototype translational vibration damper under dynamic conditions across a range of excitation frequencies. The damper’s response with the compressible fluid differed significantly from that observed with non-compressible fluids. Upon activation, the MR fluid increased flow resistance and enhanced the damper’s elastic response, posing unique challenges for further optimisation. Experimental results demonstrate the potential of employing such compressible MR fluids in applications requiring controlled material characteristics.

Keywords:
smart material, magnetorheological (MR) fluid, compressible, microspheres, vibration, damper

Loris R., Antun J., Będkowski J., Jurica J., The affordable DIY Mandeye LiDAR system for surveying caves, and how to convert 3D clouds into traditional cave ground plans and extended profiles, International Journal of Speleology, ISSN: 0392-6672, DOI: 10.5038/1827-806X.53.3.2535, Vol.53, No.3, pp.ijs2535-1-ijs2535-14, 2025

Abstract:
The paper examines the potential use of low-cost LiDAR for cave surveying. Mobile mapping using LiDAR complements traditional speleological surveying using a polygonal traverse. These methods assist each other, with one serving as an independent control measurement for the other, ultimately resulting in a more accurate 3D model. The testing results show that achieving high accuracy and detailed cave representation is possible using open hardware and open-source software. Both spacious and well-indented cave sections and narrow passages barely passable by humans were successfully mapped. The surveying process is significantly faster than traditional cave mapping, as drawing cave sketches by hand is unnecessary, being the most time-consuming task on site. This paper also presents a procedure for automated ground plan generation and profile generation from 3D point clouds, further expediting and simplifying the work for speleologists using scanning systems. Also, it is confirmed that the results are reproducible and do not depend on the subjective interpretation of the cartographer, as is the case with traditional speleological drawings.

Keywords:
cave mapping, mobile laser scanning, open hardware, open-source software, cave profiles

Nazir S., Singh P., Rawat N., Jain A., Michalska M., Yahya M., Yusuf S., Diantoro M., Polyether (polyethylene oxide) derived carbon electrode material and polymer electrolyte for supercapacitor and dye-sensitized solar cell, Ionics, ISSN: 0947-7047, DOI: 10.1007/s11581-024-06052-9, pp.1-11, 2025

Abstract:
This study investigates the development and performance analysis of a supercapacitor using activated carbon synthesized from polyethylene oxide (PEO) as the electrode material, and a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP)-based polymer electrolyte, prepared using a solution-cast technique for dye-sensitized solar cell (DSSC) application. This paper deals with polyether-based electrochemical devices, where electrode material is developed by polyethylene oxide (PEO), while an electrolyte is prepared using PVdF-HFP. Detailed electrical and photoelectrochemical studies were carried out using various characterization tools, and the results are discussed in detail. Sandwich structure supercapacitors and DSSCs are developed using maximum conducting polymer electrolyte that has an ionic conductivity of (8.3 × 10−5) Scm−1, exhibiting a high specific capacitance of 395 Fg−1 and DSSC efficiency ranging from 1.6 to 3.5% under 1 sun condition. The findings underscore the capability of PEO-derived carbon and polymer electrolytes in improving the efficiency of energy storage and conversion systems.

Keywords:
Polyether, Activated carbon, Supercapacitor, Dye-sensitized solar cell

Grigoryan N., Chudziński P., Tomonaga–Luttinger Liquid Parameters in Multiwalled Nanotubes, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, DOI: 10.1002/pssb.202400524, Vol.2400524, pp.1-10, 2025

Abstract:
Tomonaga–Luttinger liquid (TLL) theory is a canonical formalism used to describe 1D metals, where the low-energy physics is determined by collective Bosonic excitations. Herein, a theoretical model to compute the parameters of Tomonaga–Luttinger liquid (TLL) in multiwalled nanotubes (MWNTs) is presented. MWNTs introduce additional complexity to the usual Fermionic chains due to interactions and hybridization between their multiple coaxial shells. A model in which conducting paths along the length of the MWNTs are randomly distributed among the shells is considered. Since the valley degree of freedom remains a good quantum number, the TLL description in addition to spin and charge contains also valley degree of freedom and hence four-mode description applies. The values of all four TLL parameters are obtained for this model. A surprising outcome is that the compressibility of the holon mode becomes a universal quantity, while the parameters of neutral modes will depend on the details of intershell coupling. Finally, experiments where predictions can be tested are proposed.

Zargarian S., Rinoldi C., Ziai Y., Zakrzewska A., Fiorelli R., Gazińska M., Marinelli M., Majkowska M., Hottowy P., Mindur B., Czajkowski R., Kublik E., Nakielski P., Lanzi M., Kaczmarek L., Pierini F., Chronic Probing of Deep Brain Neuronal Activity Using Nanofibrous Smart Conducting Hydrogel-Based Brain–Machine Interface Probes, Small Science, ISSN: 2688-4046, DOI: 10.1002/smsc.202400463, pp.2400463-1-19, 2025

Abstract:
The mechanical mismatch between microelectrode of brain–machine interfaces (BMIs) and soft brain tissue during electrophysiological investigations leads to inflammation, glial scarring, and compromising performance. Herein, a nanostructured, stimuli-responsive, conductive, and semi-interpenetrating polymer network hydrogel-based coated BMIs probe is introduced. The system interface is composed of a cross-linkable poly(N-isopropylacrylamide)-based copolymer and regioregular poly[3-(6-methoxyhexyl)thiophene] fabricated via electrospinning and integrated into a neural probe. The coating's nanofibrous architecture offers a rapid swelling response and faster shape recovery compared to bulk hydrogels. Moreover, the smart coating becomes more conductive at physiological temperatures, which improves signal transmission efficiency and enhances its stability during chronic use. Indeed, detecting acute neuronal deep brain signals in a mouse model demonstrates that the developed probe can record high-quality signals and action potentials, favorably modulating impedance and capacitance. Evaluation of in vivo neuronal activity and biocompatibility in chronic configuration shows the successful recording of deep brain signals and a lack of substantial inflammatory response in the long-term. The development of conducting fibrous hydrogel bio-interface demonstrates its potential to overcome the limitations of current neural probes, highlighting its promising properties as a candidate for long-term, high-quality detection of neuronal activities for deep brain applications such as BMIs.

Szostakowska-Rodzoś M., Chmielarczyk M., Weronika Z., Fabisiewicz A., Kurzyk A., Myśliwy I., Kozaryna Z., Postek E. W., Grzybowska E., Plasticity of Expression of Stem Cell and EMT Markers in Breast Cancer Cells in 2D and 3D Culture Depend on the Spatial Parameters of Cell Growth; Mathematical Modeling of Mechanical Stress in Cell Culture in Relation to ECM Stiffness, Bioengineering, ISSN: 2306-5354, DOI: 10.3390/bioengineering12020147, Vol.147, No.12, pp.1-22, 2025

Abstract:
The majority of the current cancer research is based on two-dimensional cell cultures and animal models. These methods have limitations, including different expressions of key factors involved in carcinogenesis and metastasis, depending on culture conditions. Addressing these differences is crucial in obtaining physiologically relevant models. In this manuscript we analyzed the plasticity of the expression of stem cell and epithelial/mesenchymal markers in breast cancer cells, depending on culture conditions. Significant differences in marker expression were observed in different growth models not
only between 2D and 3D conditions but also between two different 3D models. Differences observed in the levels of adherent junction protein E-cadherin in two different 3D models suggest that spatial parameters of cell growth and physical stress in the culture may affect
the expression of junction proteins. To provide an explanation of this phenomenon on the grounds of mechanobiology, these parameters were analyzed using a mathematical model of the 3D bioprinted cell culture. The finite element mechanical model generated in this study includes an extracellular matrix and a group of regularly placed cells. The single-cell model comprises an idealized cytoskeleton, cortex, cytoplasm, and nucleus. The analysis of the model revealed that the stress generated by external pressure is transferred between the cells, generating specific stress fields, depending on growth conditions. We have analyzed and compared stress fields in two different growth conditions, each corresponding to a different elasticity of extracellular matrix. We have demonstrated that soft matrix conditions produce more stress than a stiff matrix in the single cell as well as in cellular spheroids. The observed differences can explain the plasticity of E-cadherin expression in response to mechanical stress. These results should contribute to a better understanding of the differences between various growth models.

Keywords:
breast cancer, E-cadherin, mechanical stress, mathematical modeling, 3D bioprinting, complex systems, cell modeling, finite element method

Jarek M., Zawalski K., Falkowski P., Zawidzka E., Zawidzki M., Simulation of 6-DOF modular Arm-Z manipulator in MATLAB Simulink, Lecture Notes in Networks and Systems, ISSN: 2367-3389, DOI: https://doi.org/10.1007/978-3-031-78266-4_16, Vol.1219, pp.1-17, 2024

Abstract:
Arm-Z is a concept of a hyper-redundant manipulator based on linearly joined sequence of congruent units. Each unit has only one degree of freedom (1-DOF) - the twist relative to the previous unit.
This paper presents the approach to design of modular robotic manipulator based on computer simulations. The approach is rather standard nowadays, however, it is applied to rather unique robotic system. The
CAD model of the module structure for a manipulator with 6 degrees of freedom and respective Denavit-Hartenberg notation are presented. Simulink - a MATLAB-based graphical programming environment was
used to determine the torques of individual modules. The results of three simulations are presented and discussed. Finally, based on critical observations, the drive and gear for the module of Arm-Z system were selected.

Keywords:
Simulation,Robotic arm,Manipulator,Arm-Z,MATLAB Simulink