Electropolishing and Shaping of Micro-Scale Metallic Features

Surface antibacterial properties enhanced through engineered textures and surface roughness: A review

The spread of bacteria through contaminated surfaces is a major issue in healthcare, food industry, and other economic sectors. The widespread use of antibiotics is not a sustainable solution in the long term due to the development of antibiotic resistance. Therefore, surfaces with antibacterial properties have the potential to be a disruptive approach to combat microbial contamination. Different methods and approaches have been studied to impart or enhance antibacterial properties on surfaces. The surface roughness and texture are inherent parameters that significantly impact the antibacterial properties of a surface. They are also directly related to the previously employed machining and treatment methods. This review article discusses the correlation between surface roughness and antibacterial properties is presented and discussed. It begins with an introduction to the concepts of surface roughness and texture, followed by a description of the most commonly utilized machining methods and surface. A thorough analysis of bacterial adhesion and growth is then presented. Finally, the most recent studies in this research area are comprehensively reviewed. The studies are sorted and classified based on the utilized machining and treatment methods, which are divided into mechanical processes, surface treatments and coatings. Through the systematic review and record of the recent advances, the authors aim to assist and promote further research in this very promising and extremely important direction, by providing a systematic review of recent advances.

Clear corneal incision, an important step in modern cataract surgery: a review

A clear corneal incision (CCI) is the most commonly used entrance site in modern phacoemulsification cataract surgery. Despite some initial concerns about increased endophthalmitis rates through a self-sealing CCI, recent literature suggests that the risk of infection with proper wound construction and all other necessary precautions is minimal. The technique of creating a clear corneal incision has, with recent developments in corneal imaging, undergone critical appraisal leading to a better understanding of incision architecture. Many surgeons operate through smaller incisions, and they have a wide choice of surgical instruments to create their corneal incisions. The aim of this review is to discuss the history and the current status of clear corneal incision creation, the design and materials of surgical blades, and the current trends in manufacturing and sustainability. Although disposable instruments have some advantages and are very popular, recycling, if possible, and avoiding unnecessary plastic waste are important considerations. In any case, the step of CCI is a small one for the surgeon, but a big one for the eye. That is why it has to be done with the utmost precision and in-depth knowledge is important.

Self-Expandable Electrode Based on Chemically Polished Nickel-Titanium Alloy Wire for Treating Endoluminal Tumors Using Bipolar Irreversible Electroporation

The application of irreversible electroporation (IRE) to endoluminal organs is being investigated; however, the current preclinical evidence and optimized electrodes are insufficient for clinical translation. Here, a novel self-expandable electrode (SE) made of chemically polished nickel-titanium (Ni-Ti) alloy wire for endoluminal IRE is developed in this study. Chemically polished heat-treated Ni-Ti alloy wires demonstrate increased electrical conductivity, reduced carbon and oxygen levels, and good mechanical and self-expanding properties. Bipolar IRE using chemically polished Ni-Ti wires successfully induces cancer cell death. IRE-treated potato tissue shows irreversibly and reversibly electroporated areas containing dead cells in an electrical strength-dependent manner. In vivo study using an optimized electric field strength demonstrates that endobiliary IRE using the SE evenly induces well-distributed mucosal injuries in the common bile duct (CBD) with the overexpression of the TUNEL, HSP70, and inflammatory cells without ductal perforation or stricture formation. This study demonstrates the basic concept of the endobiliary IRE procedure, which is technically feasible and safe in a porcine CBD as a novel therapeutic strategy for malignant biliary obstruction. The SE is a promising electrical energy delivery platform for effectively treating endoluminal organs.

Microreactor-based micro/nanomaterials: fabrication, advances, and outlook

Micro/nanomaterials are widely used in optoelectronics, environmental materials, bioimaging, agricultural industries, and drug delivery owing to their marvelous features, such as quantum tunneling, size, surface and boundary, and Coulomb blockade effects. Recently, microreactor technology has opened up broad prospects for green and sustainable chemical synthesis as a powerful tool for process intensification and microscale manipulation. This review focuses on recent progress in the microreactor synthesis of micro/nanomaterials. First, the fabrication and design principles of existing microreactors for producing micro/nanomaterials are summarized and classified. Afterwards, typical examples are shown to demonstrate the fabrication of micro/nanomaterials, including metal nanoparticles, inorganic nonmetallic nanoparticles, organic nanoparticles, Janus particles, and MOFs. Finally, the future research prospects and key issues of microreactor-based micro/nanomaterials are discussed. In short, microreactors provide new ideas and methods for the synthesis of micro/nanomaterials, which have huge potential and inestimable possibilities in large-scale production and scientific research.

Machine learning coarse-grained models of dissolutive wetting: a droplet on soluble surfaces

Dissolutive wetting is not only a key problem in application fields such as energy, medicine, micro-devices and etc., but also a frontier issue of academic research. As an important tool for exploring the micro-mechanisms of dissolutive wetting, molecular dynamics simulations are limited by simulation scale and force field parameters. Thus, artificial intelligence is introduced into the multi-scale simulation framework to tackle such challenges. By combining density functional theory, molecular dynamics simulations and experiments, we obtain a coarse-grained model of the glucose-water dissolution pair. Furthermore, the structure of the solid molecules and the hydration shell near the solute particles are calculated by quantum mechanics/molecular mechanics to verify the accuracy of the model. Finally, the applicability of the coarse-grained model in dissolutive wetting is proven by experimental results. We believe our machine learning method not only lays a foundation for exploring the micro-mechanisms of dissolutive wetting, but also provides a general approach for obtaining the force field parameters of different systems.

The efficiency of removing heavy metal ions from industrial electropolishing wastewater using natural materials

Heavy metals are present in wastewater generated by industrial sectors, posing a threat to the environment, including surface and groundwater resources. With this in mind, there is a growing interest in finding alternative yet effective methods of removing heavy metal ions from industrial wastewater. Sorption is one of the techniques being readily applied due to the simplicity, high efficiency, production of small amounts of sludge, low investment, and the feasibility of the process over a wide range of pH and temperature. This paper deals with the treatment of industrial wastewater from electropolishing of stainless steel containing high concentrations of metal ions Fe(III), Cr(III), Ni(II), and Cu(II). Taking into account the effectiveness, availability and applicability of biosorbents for acidic wastewater, orange peels, algae, Eclipta alba, and eggshells were selected for the study. Sorption tests were carried out for Eclipta alba and the results obtained showed a best fit for the second-order kinetic model (R² > 0.99) and the Langmuir isotherm model (R² > 0.99). Maximum adsorption capacity was 17.92 mg/g for mixture of metal ions. The potential use of dried and calcinated eggshells was established. Both materials achieved a high removal rate of over 95%. Iron and chromium are removed from the solution first (about 100% and 90%, respectively), followed by nickel and copper ions. FT-IR and SEM with EDS measurements used to characterize materials, together with laboratory tests using real industrial effluent, made it possible to determine their mechanism of action. Specific surface area was determined for all tested materials and the values were: 1.63, 0.15 and 5.15 m²/g for Eclipta alba, dried eggshells and calcinated eggshells, respectively. The results provide grounds for optimism in the application of selected materials for industrial wastewater treatment.