W. O. Soboyejo

Worcester Polytechnic Institute | WPI · Department of Mechanical Engineering

This paper presents the results of a combined experimental and theoretical study of the structure and viscoelastic properties of human non-tumorigenic mammary breast tissues and triple negative breast cancer (TNBC) tissues of different histological grades. A combination of immunofluorescence and confocal microscopy, and atomic force microscopy is u...

Low- and middle-income countries have tremendous potential for renewable energy production, including production of renewable carbon from locally prolific crops. In this work, bamboo endemic to West Africa (Bambusa vulgaris) was studied as a feedstock for the production of renewable sugars as the gateway to the local production of biofuels and bio-...

Breast cancer (BC) is currently the most common form of cancer diagnosed worldwide with an incidence estimated at 2.26 million in 2020. Additionally, BC is the leading cause of cancer death. Many subtypes of breast cancer exist with distinct biological features and which respond differently to various treatment modalities and have different clinica...

This article presents silica nanoparticles for the sustained release of AMACR antibody‐conjugated and free doxorubicin (DOX) for the inhibition of prostate cancer cell growth. Inorganic MCM‐41 silica nanoparticles were synthesized, functionalized with phenylboronic acid groups (MCM‐B), and capped with dextran (MCM‐B‐D). The nanoparticles were then...

This article explains the impact of an additive manufacturing technique known as cold spray and its applications in alloy design and manufacturing. The process involves the bombardment or impinging the surface of an alloy with micro-sized powders using low reactive gasses. The temperature of gas and powders are much lower than their melting point r...

Batteries and electrochemical capacitor (Supercapacitors) play significant roles amongst the Electrochemical energy storage systems and are driven electrochemically by adsorption (electrosorption) and insertion of ions into solid materials. These process often lead to significant volume changes during electrochemical measurements. These large volum...

Breast cancer accounts for 30% of all female cancers. Accurately distinguishing dangerous malignant tumors from benign harmless ones is key to ensuring patients receive lifesaving treatments on time. However, as doctors currently do not identify 10% to 30% of breast cancers during regular assessment, automated methods to detect malignant tumors are...

This article discusses potential applications of complex concentrated alloys (CCAs) focusing on structural and functional applications. Structural materials are used under load-bearing conditions and applications, whereas functional materials are driven by the physico-chemical behavior focusing on magnetic, thermal, dielectric, optical, catalytic,...

This article reviews strain gradient plasticity (SGP) and its associated length scales in metals. An introduction to material length scales and scale dependent plasticity provides motivation for the study and use of SGP. Proposed fundamental mechanisms behind strain gradient plasticity and the reasoning for its relationship with material length sca...

This paper presents the results of a combined experimental and theoretical study of the effects of sintering temperature on the mechanical and filtration properties of clay ceramic water filters (CWFs). CWFs produced from 50:50 volume proportion mixtures of clay and sieved sawdust (porogen) were sintered at 850°C, 900°C and 950°C to produce micro-...

Complex concentrated alloys are designed by mixing elements in equiatomic or near equiatomic proportions. The nature of bonding and inter-element interactions of constituents resulting in microstructures that induces superior mechanical properties than for conventional alloys. This disruptive alloy design technique benefits from high configuration...

Dental restorations, including crowns, bridges, and implants, are designed to repair and restore damaged or missing teeth. All-ceramic restorations are widely used because of their biocompatibility and esthetics. However, their strength and fatigue life are not satisfactory and clinical complications including ceramic fracture and loss of retention...

Mechanics and materials can provide extra information at the nanoscale to help us better understand cancer diagnosis and treatment. A large body of scientific evidence indicates cancer is associated with specific changes in cells׳ mechanical characteristics and extracellular environment. This argument is supported by several recent developments in...

This article discusses the limitations of equiatomic composition design strategy of complex concentrated alloys (CCAs). The maximization of configurational entropy and stabilization of single solid solution phases have weak correlation on equiatomic compositions as initially hypothesized. Equiatomic compositions are restrictive, and the mechanical...

This article presents comprehensive insights and a review of cell/surface interactions on Ti-6AI-4V surfaces that are relevant to biomedical implants. The effects of surface texture are discussed for the development of biomedical implants for applications in orthopedics and dentistry. These include textured screws that have been developed along wit...

This need to reconstruct and regenerate breast tissue is crucial to avoid the excruciating implication associated with the conventional methods that involves the total removal (mastectomy) of the breast due to the presence of breast cancer disease. In this article, we present different ideas that explore the potential use of different structures ba...

External interventions are required to restore the body’s function when it is challenged beyond its natural healing ability by critical size defects. As a result, regenerative medicine techniques are being developed to regenerate or repair tissues and organs to circumvent the limitations of conventional grafts being used for tissue/organ repair. Th...

This article presents some insights on the fatigue of defects in steel materials and structures. Following a brief review of the underlying mechanisms and mechanics of fatigue, we present some mechanistic insights into the growth of single and multiple coplanar and non-coplanar surface cracks. These include single semi-elliptical cracks; coplanar s...

This article presents and overview of the fatigue of thermostructural alloys focusing on structural steels, titanium and its alloys, nickel and its alloys and thermal barrier coatings. Factors contributing to the fatigue behavior of these thermostructural alloys such as stress ratio, operating environment and microstructural features have been disc...

This article presents an overview of the fatigue of silicon and nickel Micro-Eectro-Mechanical Systems (MEMS) thin films. Following a brief review of the role of topical oxide films in the fatigue of micron-scale structures, the nucleation and growth of Silicon and Nickel-based Micro-Eectro-Mechanical Systems (MEMS) is explored. Materials and mecha...

This article presents some insights and current review of the current understanding of fatigue in biomaterials and biomedical systems. The fatigue mechanisms associated with dental materials, hip implants, heart valves, knee implants, screws and plates, and stents were reviewed considering advances and innovation in the field of biomaterials. Fatig...

This article presents concepts for the design of bioinspired bamboo structures. The knowledge of deformation and failure mechanisms in bamboo structures is used to provide insights that can guide the design of bamboo structures that are subjected to compressive loading. The article is divided into six sections. An overview of the understanding of t...

This article presents an overview of the fatigue and fracture mechanisms and toughening of some group of intermetallics. Fracture toughness and fatigue crack growth of α2 and γ-based titanium aluminides as well as niobium aluminides and molybdenum disilicides are elucidated. Following a brief introduction for these group of intermetallics, the toug...

The adhesive interactions between molecular recognition units (such as specific peptides and antibodies) and antigens or other receptors on the surfaces of tumours are of great value in the design of targeted nanoparticles and drugs for the detection and treatment of specific cancers. In this paper, we present the results of a combined experimental...

s The interplay between mechanical and optoelectronic properties is becoming very interesting reliability evaluation of solar cells. Emerging flexible and stretchable solar cells also required an in-depth understanding of mechanical properties of layered thin film constituents. This article explores the mechanical properties of solar cell structure...

Complex concentrated alloys can address major materials-related engineering challenges of our time. These range from the strength-ductility trade-offs in metallic alloys, to lightweight alloys and superior combinations of properties required for structural and functional applications. Despite such cornucopia, there are serious factors that are majo...

Reliability of electronic systems that are used for applications where flexibility and stretchability are required are becoming necessary in this modern world. Since these flexible and stretchable electronic structures are designed to undergo stress-induced deformation during service condition, it is importance to understand their fatigue behavior....

Mechanical properties of solid-state Li-ion batteries (SSLIBs) are desirable in the design of robust, safe and reliable battery systems for green energy solutions. This article presents the mechanical properties of SSLIBs. The overview of challenges of the SSLIBs is explored before elucidating the various design of electrolytes for SSLIBs. The mech...

The control of the cation composition of formamidinium (FA), methylammonium (MA), and cesium (Cs) has been used to engineer significant improvements in organic–inorganic perovskite solar cells. However, the thermal stability of mixed-cation perovskite solar cells is not fully understood. In this work, we present the results of an experimental study...

In this paper, we use Polyethylene Oxide (PEO) particles to control the morphology of Formamidinium (FA)-rich perovskite films and achieve large grains with improved optoelectronic properties. Consequently, a planar perovskite solar cell (PSC) is fabricated with additions of 5 wt% of PEO, and the highest PCE of 18.03% was obtained. This solar cell...

This paper presents the results of an experimental and computational study of the effects of laser‐induced heating provided by magnetite nanocomposite structures that are being developed for the localized hyperthermic treatment of triple‐negative breast cancer. Magnetite nanoparticle‐reinforced polydimethylsiloxane (PDMS) nanocomposites were fabric...

This paper presents the results of a combined experimental and computational study of the role of deformation and cracking phenomena on the cold spray processing of refractory Ta powders with topical nanoscale oxide layers. The structure of the Ta powders and the topical nanoscale oxide films are elucidated using a combination of Scanning Electron...

Over the years, the cost and environmental issues with the utilization of conventional building materials such as cement and river sand for housing projects kept increasing with the increase in the human population. This has led researchers to explore alternative building materials that are affordable and sustainable. This study is aimed at develop...

A combination of experiments and theoretical models is used to study the mechanical and thermal properties of polydimethylsiloxane (PDMS) and magnetite nanoparticle‐reinforced PDMS composites with the potential for applications in biomedical implants for localized hyperthermia and photothermal ablation. Composite samples with varying weight fractio...

This paper presents the results of an experimental and computational study of the adhesion of triptorelin-conjugated PEG-coated biosynthesized gold nanoparticles (GNP-PEG-TRP) to triple-negative breast cancer (TNBC) cells. The adhesion is studied at the nanoscale using a combination of atomic force microscopy (AFM) experiments and molecular dynamic...

This paper presents the results of a combined experimental and computational study of the mechanisms of blister formation, and their effects on the degradation of organic light emitting devices (OLEDs). Blister formation is attributed to the effects of thermally induced mismatch stresses associated with applied bias. These result in interfacial cra...

The demand for flexible, lightweight, and long‐lasting energy devices has stimulated interest in solid polymer blends. The conventional lithium‐ion batteries use liquid electrolytes that are chemically unstable due to the presence of carbonates, which are highly volatile and flammable, creating a significant safety risk. Therefore, the need for the...

This paper presents deformation and cracking phenomena associated with the cold spray of nanoscale surface oxide layers associated with the cold spray of 6061 Al alloy powders. The structure of the top surface oxide film was revealed via Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). The...

In this paper, we use a combination of computational models and experiments to study the effects of stack pressure on interfacial contacts and deformation of solid state electrolytes in an all solid state battery (ASSB). The induced strain distributions in the LiBH4–LiNH2 based all solid-state battery are measured using a combination of in-situ opt...

This paper uses a combination of experiments and theory to study the effects of annealing temperature on the mechanical properties of hybrid organic–inorganic perovskites (HOIPs). We examined the mechanical (hardness and Young’s modulus), microstructural, and surface topography properties of the HOIP film at different annealing temperatures ranging...

The understanding of the degradation mechanisms in perovskite solar cells (PSCs) is important as they tend to degrade faster under exposure to heat and light conditions. This paper examines the temperature-dependent degradation of solution processed triple-cation mixed halide PSCs (Cs0.05(FA0.95MA0.05)0.95Pb(I0.9Br0.05)3). The PSCs were subjected t...

In this work, mechanochemical pretreatment of Bambusa vulgaris is evaluated for waste-free production of renewable sugars for subsequent fermentation. After a 60 min mechanochemical pretreatment followed by enzyme hydrolysis at 50 °C, 62% of the available carbohydrate can be recovered as fermentable sugars, primarily in the form of glucose and xylo...

Both Stress Corrosion Cracking (SCC) and Corrosion Fatigue Cracking (CFC) are forms of environmental cracking; they lead to structural damage and progressively to catastrophic failure, if not checked on time. During service, huge amount of money is spent to either lessen or control the damage caused by SCC and CFC. The likelihood of failure resulti...

This article presents an overview of environmentally-assisted cracking and corrosion fatigue in steels. Following a brief review of environmentally-assisted cracking by hydrogen embrittlement and anodic dissolution, the mechanisms of corrosion and environmentally-assisted crack growth are elucidated for coated and uncoated structural steels that ar...

Highlights On-farm samples were used to analyze farmers’ exposure to dust while cleaning and unloading their grain bins. Over 18% of samples exceeded the 8-hour time-weighted average (TWA) concentration recommended by ACGIH for respirable dust, and over 27% of samples exceeded the ACGIH recommendation for total suspended particles. The results stre...

This article presents the correlation of creep and viscoelastic properties to the cytoskeletal structure of both tumorigenic and non-tumorigenic cells. Unique shear assay and strain mapping techniques were used to study the creep and viscoelastic properties of single non-tumorigenic and tumorigenic cells. At least 20 individual cells, three locatio...

This paper examines the effects of hydroxyapatite (HA) and bone-particle (BP) doping on the removal of fluoride and bacteria by ceramic water filters (CWFs). The CWFs were produced by mixing clay, sieved sawdust, and either HA or BPs in a weight ratio of 30:50:20 and sintered at 850°C or 900°C to produce micro-/ nano-porous structures that remove m...

This paper presents in vitro studies of the sustained release of Annona muricata leaf extracts (AME) from hybrid electrospun fibers for breast cancer treatment. Electrospun hybrid scaffolds were fabricated from crude AME extracts, poly(lactic-co-glycolic acid)/gelatin (PLGA/Ge) and pluronic F127. The physicochemical properties of the AME extract an...

Environmental implications of the extensive use of cement and concrete as building materials have significantly increased over the years. In order to mitigate the harmful impact of the cement and concrete industry, the utilization of alternative sustainable and eco-friendly building materials has become imperative. This study assesses the current s...

This paper presents the results of study on indentation size effects in structural metals/alloys (6061 aluminum alloy, titanium and Ti–6Al–4V) at the micron scale. The size dependence of indentation hardness is explained using strain gradient plasticity theories introduced by Nix and Gao (J. Mech. Phys. Solids., 46 (1998), 411–425). Resulting mater...

The design of electron transport layers (ETLs) with good optoelectronic properties is one of the keys to the improvement of the power conversion efficiencies (PCEs) and stability of perovskite solar cells (PSCs). Titanium dioxide (TiO2), one of the most widely used ETL in PSCs, is characterized by low electrical conductivity that increases the seri...

The interfacial robustness of perovskite solar cells (PSCs) is important due to the potential for failure resulting from applied loads or deformation in devices that are fabricated on rigid or flexible substrates, and/or residual stresses due to thermal expansion mismatch between layers. Since these can occur across any of the interfaces within typ...

All-solid-state batteries based on solid-state electrolytes (SSE) have attracted considerable attention due to their high capacity and relative safety, compared to conventional batteries based on liquid electrolytes. As ions migrate from the electrodes through solid electrolytes (during charge and discharge cycles of an all-solid-state battery), th...

The challenges in housing and urban infrastructure development in Nigeria are enormous. This work is aimed at exploring the role of research and innovation in overcoming the challenges. It is indeed captured in Goal 11 of the Sustainable Development Goals (SDGs) which aims at making cities and human settlements inclusive, safe, resilient and sustai...

This paper presents the results of experimental and analytical studies of the failure mechanisms of stretchable perovskite light‐emitting devices (PeLEDs). The multilayered PeLED structures consist of an anodic layer of poly(3,4‐ethylenedioxythiophene):polystyrene‐sulfonate (PEDOT:PSS), an emissive layer of methylammonium lead bromide (MAPbBr3), an...

Incorporation of cesium (Cs) into the perovskite layer has become a good strategy to boost the stability and power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, a suitable and scalable method of Cs incorporation in a perovskite film that does not cause a significant increase in the optical bandgap is needed. In this paper,...

In this study, we explore the development of controlled PLGA-CS-PEG microspheres, which are used to encapsulate model anticancer drugs (prodigiosin (PGS) or paclitaxel (PTX)) for controlled breast cancer treatment. The PLGA microspheres are blended with hydrophilic polymers (chitosan and polyethylene glycol) in the presence of polyvinyl alcohol (PV...

This paper presents the results of a combined experimental and theoretical study of the interfacial and mechanical properties of epoxy/clay composites coatings on a mild steel substrate. This was studied using nano-indentation and Brazil Disk techniques to determine the Young’s moduli, hardness values and mode mixity characteristics of the composit...

Annealing is one of the processing methods that are used for the fabrication of defect-free, photoactive perovskite films with compact grains in highly efficient and stable perovskite solar cells (PSCs). Thus, the annealing temperature is a key parameter for the control of the interdiffusion (of constituent elements) in photoactive films. In this p...

This article presents the results of cell–surface interactions on polydimethylsiloxane (PDMS)‐based substrates coated with nanoscale gold (Au) thin films. The surfaces of PDMS and PDMS–magnetite (MNP)‐based substrates were treated with UV‐ozone, prior to thermal vapor deposition (sputter‐coated) of thin films of titanium (Ti) onto the substrates to...

The COVID-19 global pandemic has caused a profound change in the teaching pedagogies and assessment strategies in engineering curricula worldwide. Concerning this, the article examines the role of animation-enhanced concept-in-context maps as a learning resource for the introductory materials science course in an online flipped format. The research...

Various research works have been carried out on cement and lime stabilization of lateritic soil. The production of cement is too expensive and environmentally unfriendly due to the required huge embodied energy as well as the environmental pollution resulting in ozone layer depletion. In order to minimize these shortcomings, researchers are explori...

This paper presents the results of experimental and theoretical studies of the effects of pressure and thermal annealing on the photo-conversion efficiencies (PCEs) of polymer solar cells with active layers that consist of a mixture of poly(3-hexylthiophene-2,5-diyl) and fullerene derivative (6,6)-phenyl-C61-butyric acid methyl ester. The PCEs of t...

This paper presents the results of a study of the actin cytoskeletal structures and the statistical variations in the actin fluorescence intensities and viscoelastic properties of non-tumorigenic breast cells and triple-negative breast cancer cells at different stages of tumor progression. The variation in the actin content of the cell cytoskeletal...

This article presents the release kinetics (RK) of a fungicidal antimicrobial agent (AMA), potassium sorbate (PS), that prolongs the shelf life of packaged food. The effects of PS release are explored on peanut and fresh bread to determine the effects of PS on Aspergillus niger (AN) microbe growth. The AN was cultured in a potato dextrose agar (PDA...

Novel severe acute respiratory syndrome coronavirus 2 (COVID-19) has become a pandemic of epic proportions, and global response to prepare health systems worldwide is of utmost importance. 2-dimensional (2D) lung ultrasound (LUS) has emerged as a rapid, noninvasive imaging tool for diagnosing COVID-19 infected patients. Concerns surrounding LUS inc...