Highly Conductive Collagen by Low-Temperature Atomic Layer Deposition of Platinum

Advances in core technologies for semiconductor manufacturing: applications and challenges of atomic layer etching, neutral beam etching and atomic layer deposition

This article comprehensively reviews the technological advancements, emerging materials, processing techniques adopted (atomic layer deposition, atomic layer etching, and neutral beam etching), geometric influences, and fabrication challenges in the development of advanced semiconductor devices. These technologies are recognized for their precision at the atomic scale and are crucial in fabricating next-generation silicon photonics optoelectronic devices. They also play an important role in the development of RF/power third-generation compound semiconductors and advanced semiconductor devices. Atomic layer deposition (ALD) offers superior control over thin film growth, ensuring uniformity and material conformity. Atomic layer etching (ALE) enables precise layer-by-layer material removal, making it ideal for high-aspect-ratio structures. Neutral beam etching (NBE) minimizes surface damage, a key factor in maintaining device reliability, particularly for GaN-based semiconductors. This article also assesses the role of these technologies in enhancing semiconductor device performance, with a focus on overcoming the limitations of traditional methods. The combined application of ALD, ALE, and NBE technologies is driving innovations in advanced semiconductor fabrication, making these processes indispensable for advancements in areas such as micro-LEDs, optical communication, and high-frequency, high-power electronic devices.

Functionalization of collagen fiber with nano-islands of silver via atomic layer deposition to promote bone healing

Modern techniques of thin film deposition (e.g., atomic layer deposition [ALD]) have paved the way for the modification of the surface of target substrates with thin films, nanoparticles, or other types of nanomaterials. This novel way can improve the base material's properties and enhance specific properties through adding functionalized groups to the surface. In this study, ALD of silver was conducted on commercially available Type I collagen membrane to improve its bioactivity and promote bone healing. Two different sample groups were studied: pristine collagen and silver-coated collagen via ALD (Ag/Collagen). Chemical and morphological changes of the collagen membrane were investigated with X-ray photoelectron spectroscopy and scanning electron microscopy and the bioactivity of functionalized collagen with silver was studied in vitro and in vivo. Nano-islands of silver were obtained on collagen fibrils with an average diameter of ∼16 nm. Comparison of gingival cells cultured on pristine collagen, and silver-coated collagen, demonstrated that the attained silver nanoparticle size and concentration are below the toxicity level of silver. In vivo assessment in rat model showed the biocompatibility of the Ag/Collagen, and greater new bone formation compared to control. This novel solvent-free method can be used to functionalize sensitive materials used in surgeries as bone grafting agents to enhance osteopromotive properties without any adverse effects to the cellular environment.

Collagen Membranes Functionalized with 150 Cycles of Atomic Layer Deposited Titania Improve Osteopromotive Property in Critical-Size Defects Created on Rat Calvaria

The membranes used in bone reconstructions have been the object of investigation in the field of tissue engineering, seeking to improve their mechanical strength and add other properties, mainly the osteopromotive. This study aimed to evaluate the functionalization of collagen membranes, with atomic layer deposition of TiO2 on the bone repair of critical defects in rat calvaria and subcutaneous biocompatibility. A total of 39 male rats were randomized into four groups: blood clot (BC), collagen membrane (COL), COL 150—150 cycles of titania, and COL 600—600 cycles of titania. The defects were created in each calvaria (5 mm in diameter) and covered according to each group; the animals were euthanized at 7, 14, and 28 days. The collected samples were assessed by histometric (newly bone formed, soft tissue area, membrane area, and residual linear defect) and histologic (inflammatory cells and blood cells count) analysis. All data were subjected to statistical analysis (p < 0.05). The COL150 group showed statistically significant differences compared to the other groups, mainly in the analysis of residual linear defects (1.5 ± 0.5 × 106 pixels/µm2 for COL 150, and around 1 ± 0.5 × 106 pixels/µm2 for the other groups) and newly formed bone (1500 ± 1200 pixels/µm for COL 150, and around 4000 pixels/µm for the others) (p < 0.05), demonstrating a better biological behavior in the chronology of defects repair. It is concluded that the collagen membrane functionalized by TiO2 over 150 cycles showed better bioactive potential in treating critical size defects in the rats’ calvaria.

Protein and Polysaccharide-Based Electroactive and Conductive Materials for Biomedical Applications

Electrically responsive biomaterials are an important and emerging technology in the fields of biomedical and material sciences. A great deal of research explores the integral role of electrical conduction in normal and diseased cell biology, and material scientists are focusing an even greater amount of attention on natural and hybrid materials as sources of biomaterials which can mimic the properties of cells. This review establishes a summary of those efforts for the latter group, detailing the current materials, theories, methods, and applications of electrically conductive biomaterials fabricated from protein polymers and polysaccharides. These materials can be used to improve human life through novel drug delivery, tissue regeneration, and biosensing technologies. The immediate goal of this review is to establish fabrication methods for protein and polysaccharide-based materials that are biocompatible and feature modular electrical properties. Ideally, these materials will be inexpensive to make with salable production strategies, in addition to being both renewable and biocompatible.