Innovative Fabrication Research Articles

Skin-Inspired Thermoreceptors-Based Electronic Skin for Biomimicking Thermal Pain Reflexes.

Electronic systems possessing skin‐like morphology and functionalities (electronic skins [e‐skins]) have attracted considerable attention in recent years to provide sensory or haptic feedback in growing areas such as robotics, prosthetics, and interactive systems. However, the main focus thus far has been on the distributed pressure or force sensors. Herein a thermoreceptive e‐skin with biological systems like functionality is presented. The soft, distributed, and highly sensitive miniaturized (≈700 µm2) artificial thermoreceptors (ATRs) in the e‐skin are developed using an innovative fabrication route that involves dielectrophoretic assembly of oriented vanadium pentoxide nanowires at defined locations and high‐resolution electrohydrodynamic printing. Inspired from the skin morphology, the ATRs are embedded in a thermally insulating soft nanosilica/epoxy polymeric layer and yet they exhibit excellent thermal sensitivity (−1.1 ± 0.3% °C−1), fast response (≈1s), exceptional stability (negligible hysteresis for >5 h operation), and mechanical durability (up to 10 000 bending and twisting loading cycles). Finally, the developed e‐skin is integrated on the fingertip of a robotic hand and a biological system like reflex is demonstrated in response to temperature stimuli via localized learning at the hardware level.

Multifunctional photo-Fenton-active membrane for solar-driven water purification

Photo-Fenton-active (PFA) membranes can provide an effective strategy to control various organic pollutants in water purification applications by simultaneously promoting photocatalysis and Fenton reaction. However, the fabrication of PFA membranes with high reactivity and stability remains a significant technical challenge. In this study, we present a simple and versatile technique to fabricate a PFA membrane via in-situ functionalization of polypyrrole (PPy, i.e., photothermal catalyst) and zerovalent iron (ZVI, i.e., photo-Fenton catalyst) nanoparticles. The proposed one-pot two-step protocol involves vapor phase polymerization of pyrrole and subsequent reduction of iron source, which successfully creates a thin catalyst coating on a porous substrate without reducing membrane porosity. The PFA membrane with the dual PPy/ZVI catalyst layer showed high surface wettability, photothermal performance, and photo-Fenton reactivity, thereby enabling effective control of organic contaminants. Specifically, the PFA membrane exhibited near complete removal (>97%) of organic dye molecules in five repeated photo-Fenton-oxidation cycles. We found that robust anchoring of the ZVI within the PPy layer is an important factor for stable photo-Fenton activity of the PFA membrane. The enhanced anti-fouling and self-cleaning properties of the PFA membrane were further demonstrated in oil-emulsion filtration experiments with multiple cycles. Our innovative fabrication approach can serve as a versatile platform for the development of highly reactive and stable PFA membranes for a wide range of solar-driven water treatment applications.

Nanomicelles Array for Ultrahigh-Density Data Storage.

High-density data storage devices based on organic and polymer materials are currently restricted by two key issues, size limitations and uniformity of memory cells. Herein, one triblock polymer is synthesized by ring-opening metathesis polymerization, where the polymer contains an electron-donor-acceptor (A1 D) segment, an electron-acceptor (A2 ) segment, and a hydrophilic segment, that shows ternary memory behavior in a conventional sandwich-type device. The polymers that have monodisperse molecular weight dispersity self-assemble into nanomicelles with a uniform size of 80nm. Each nanomicelle is composed of an A1 DA2 -type hydrophobic core stabilized with a hydrophilic shell. Nanobowls based on conductive oxide are prepared via the template method, wherein the nanomicelles are present as independent nanoscale memory units to produce an array of micelle matrices. Investigations of the resulting nanomemory device using conductive atomic force microscopy show that the micelles exhibit a predominant semiconductor memory behavior. Compared to traditional ternary devices with a memory unit size of ≈1mm, this innovative fabrication method based on arrayed uniform nanomicelles downscales the size of storage cells to 80nm. Furthermore, the described system leads to a greatly enhanced storage density (>108 times over the same area), which opens up new paths for further development of ultrahigh-density data storage devices.

Designing and Producing Innovative Composites Fabrics for Jeans on Jacquard Weaving Looms with Distinct Characteristics that are Compatible with Fashion Developments

Designing and Producing Innovative Composites Fabrics for Jeans on Jacquard Weaving Looms with Distinct Characteristics that are Compatible with Fashion Developments

Fog Harvesting Devices Inspired from Single to Multiple Creatures: Current Progress and Future Perspective (Adv. Funct. Mater. 26/2022)

Fog Harvesting Devices Freshwater scarcity is increasingly becoming a global systemic risk. In article number 2200359, Tianxue Zhu, Shaohai Fu, Yuekun Lai, and co-workers summarize the innovative fabrication strategies and fundamental fog harvesting mechanism of bioinspired surfaces with special wettability that can pioneer a promising development direction on the construction of fog harvesting devices for solving the water crisis.

4D Printing Applications in the Development of Smart Cardiovascular Implants.

Smart materials are able to react to different stimuli and adapt their shape to the environment. Although the development of 3D printing technology increased the reproducibility and accuracy of scaffold fabrication, 3D printed scaffolds can still be further improved to resemble the native anatomy. 4D printing is an innovative fabrication approach combining 3D printing and smart materials, also known as stimuli-responsive materials. Especially for cardiovascular implants, 4D printing can promisingly create programmable, adaptable prostheses, which facilitates implantation and/or create the topology of the target tissue post implantation. In this review, the principles of 4D printing with a focus on the applied stimuli are explained and the underlying 3D printing technologies are presented. Then, according to the type of stimulus, recent applications of 4D printing in constructing smart cardiovascular implants and future perspectives are discussed.

Design and characterization of a 3D printed miniature actuator using shape memory alloy wires

Microfluidics has been at the center of attention in chemical and biological sciences over the last decade since it can miniaturize many laboratory-based applications. However, the transition from concept to a practical microfluidic chip is greatly hindered due to the widespread conventional soft lithography techniques which are used for the fabrication of the microfluidic chips. These methods are not time- and cost-efficient. Additive manufacturing technique (i.e. 3D printing) has grown in many research fields. Many conventional microfluidic system component designs have been adapted to the 3D printing manufacturing techniques. Three-dimensional printed active components such as microvalves and micropumps have also been studied, however, almost all the designs depend on an external pneumatic control unit or syringe pumps so far. In this study, we aimed to address the lack of a microfluidic active component with an integrated actuator unit. We used a shape memory alloy as the actuator. In doing so, we employed an innovative batch fabrication method that utilizes 3D printing. The proposed actuator design can produce high work and concurrently isolate the heat source from the fluidic sample which is of utmost importance for biological samples. The results show that the miniature actuator can block high pressure (up to 150 mmHg) silicone channel partially or completely depending on the application requirements. The actuation time can be controlled electronically and reduced to times as low as 100 ms. In conclusion, this design proved to be a promising candidate for the development of flow control components such as microvalves, micropumps, or micromixers.

Stem Cell-Laden Hydrogel-Based 3D Bioprinting for Bone and Cartilage Tissue Engineering.

Tremendous advances in tissue engineering and regenerative medicine have revealed the potential of fabricating biomaterials to solve the dilemma of bone and articular defects by promoting osteochondral and cartilage regeneration. Three-dimensional (3D) bioprinting is an innovative fabrication technology to precisely distribute the cell-laden bioink for the construction of artificial tissues, demonstrating great prospect in bone and joint construction areas. With well controllable printability, biocompatibility, biodegradability, and mechanical properties, hydrogels have been emerging as an attractive 3D bioprinting material, which provides a favorable biomimetic microenvironment for cell adhesion, orientation, migration, proliferation, and differentiation. Stem cell-based therapy has been known as a promising approach in regenerative medicine; however, limitations arise from the uncontrollable proliferation, migration, and differentiation of the stem cells and fortunately could be improved after stem cells were encapsulated in the hydrogel. In this review, our focus was centered on the characterization and application of stem cell-laden hydrogel-based 3D bioprinting for bone and cartilage tissue engineering. We not only highlighted the effect of various kinds of hydrogels, stem cells, inorganic particles, and growth factors on chondrogenesis and osteogenesis but also outlined the relationship between biophysical properties like biocompatibility, biodegradability, osteoinductivity, and the regeneration of bone and cartilage. This study was invented to discuss the challenge we have been encountering, the recent progress we have achieved, and the future perspective we have proposed for in this field.

786 Electrical Injury Resulting In Bilateral Upper Extremity Amputation: Improving Independence And Quality Of Life

IntroductionFifty seven year old male who sustained an electrical burn injury that resulted in bilateral below elbow amputation began inpatient rehabilitation program. Patient was motivated to increase independence to return home prior to prosthetic fitting and training being completed. Quality options for adaptive equipment required to increase independence were not sufficient to meet patients needs, thus innovative specialty fabrication of adaptive equipment were required to meet patient’s goals of independence.MethodsOccupational therapist to use thermoplastic material to fabricate various adaptive equipment in order to address patient's goals to increase independence with self care tasks. Occupational therapist and patient to have one time consult with hospital maintenance employee to create pant hook to use for ease of donning/doffing over hips. Patient participated in daily Occupational therapy sessions focused on trialing adaptive equipment and to provide feedback for any desired changes of equipment to maximize patient progress and success with reaching independence with self cares and return to life roles.ResultsPatient met all goals to become independent with self care tasks including: toileting, dressing and showering as a result of using fabricated adaptive equipment and techniques addressed during therapy sessions. Patient able to return home independently following discharge from inpatient rehabilitation stay.ConclusionsUse of easily accessible ezeform thermoplastic material can result in fabrication of adaptive equipment to increase patient's independence. It is important to maintain a creative outlook as a clinician and to continue to collaborate with our patient's to identify barriers to success and explore options to increase patient's desired independence.

A Review of Natural Fibers Reinforced Composites for Railroad Applications

Composite materials are abundantly present in applications related to transportation industries, mainly due to their lightweight, good mechanical performance, and viable production costs. In this sector, weight reduction represents a two-fold advantage as fuel consumption can be reduced, as well as passenger (or load) capacity can be enhanced. The use of natural fiber composites is an excellent option considering weight reduction and source renewability, already being done in many automotive and aerospace utilities, but specifically in railroad applications, their choice seems to be eclipsed by synthetic fibers, such as glass and carbon fibers. The objective of this work is to analyze the current situation on composite applications in the railroad industry, deriving a discussion that includes the aspects that hinder the use of natural fibers and also indicates the current status of greener composites even if not including natural fibers. The production costs of these natural fiberreinforced composites, when observed under a scalability scenario, associated with some specific properties of natural fibers (as flammability performance, for example) seem to be the reason for their rather infrequent consideration. Nevertheless, technology advancements related to production processes and innovative additives fabrication present an interesting prospect for future development in agreement with sustainability concerns.

Fog Harvesting Devices Inspired from Single to Multiple Creatures: Current Progress and Future Perspective

AbstractThe increasing demand for clean water driven by the rapid growth of the population and the pollution of water necessitates the development of direct and rapid water harvesting methods. Fog harvesting is proven as a highly efficient water capture method in dry but foggy areas. Herein, the state‐of‐the‐art developments on the multiple biomimetic fog harvesting devices (FHDs) are presented. First, the fundamental and specific mechanisms of fog harvesting involving the Namib Desert beetle, spider silk, cactus, and Nepenthes alata are described in detail, respectively. Second, an in‐depth discussion on the mechanisms of fog harvesting including fog capture and water transport is proposed. Third, a detailed account of the innovative design strategies and fabrication technologies of FHDs is proposed, from single to multiple biomimetic FHDs with typical examples and the merits and demerits are compared. Finally, a critical analysis of current challenges and future development is presented, aiming to promote next‐generation FHDs from scientific research to practical application.

Microstructure and mechanical performance of zirconium, manufactured by selective laser melting

Additive manufacturing as an innovative material fabrication technique has been attracting increasing attention from academia and industry in recent years. However, intensive studies on additive manufacturing of zirconium and its alloy are very scarce due to the challenge of fabrication technology. Herein, commercially pure zirconium (CP–Zr) components with high mechanical properties in terms of strength and plasticity were successfully manufactured by selective laser melting (SLM) under an argon atmosphere. The microscopic characteristics and mechanical properties of as-processed CP-Zr were comprehensively investigated by the means of optical microscope (OM), transmission electron microscope (TEM) and universal tensile testing machine. The characterization experiments indicated that the as-built microstructure of CP-Zr was composed of a large amount of ultra-fine α' martensite locating inside the columnar prior β grains, and massive dislocations and twins distributing in martensite or matrix. Based on the tensile testing, the as-built samples achieved a great ultimate tensile strength of 746.3 MPa and a high elongation of 27.1%. Due to the formation of ultra-fine microstructure and the synergistic effect of dislocations and twins, the strength and plasticity of as-built objects are 96% and 69% higher than the wrought CP-Zr cubes required in ASTM-523, respectively. In this work, a near-net shape method was innovatively proposed for fabricating zirconium and its alloy components. As well, a perspective insight was provided for investigating the strengthening and deformation mechanism of SLM-manufactured CP-Zr.

Scalable batch fabrication of ultrathin flexible neural probes using a bioresorbable silk layer

Flexible intracerebral probes for neural recording and electrical stimulation have been the focus of many research works to achieve better compliance with the surrounding tissue while minimizing rejection. Strategies have been explored to find the best way to insert flexible probes into the brain while maintaining their flexibility once positioned. Here, we present a novel and versatile scalable batch fabrication approach to deliver ultrathin and flexible probes consisting of a silk-parylene bilayer. The biodegradable silk layer, whose degradation time is programmable, provides a temporary and programmable stiffener to allow the insertion of ultrathin parylene-based flexible devices. Our innovative and robust batch fabrication technology allows complete freedom over probe design in terms of materials, size, shape, and thickness. We demonstrate successful ex vivo insertion of the probe with acute high-fidelity recordings of epileptic seizures in field potentials as well as single-unit action potentials in mouse brain slices. Our novel technological solution for implanting ultraflexible devices in the brain while minimizing rejection risks shows high potential for use in both brain research and clinical therapies.

Chemical Vapor Deposition for Advanced Polymer Electrolyte Fuel Cell Membranes

AbstractFuel cells will play a critical role in a renewable energy powered society, whether in mobility or stationary applications. Certain challenges remain to be addressed if performance and cost dynamics of these systems is to achieve large scale, high unit number roll out. This review deals with polymer electrolyte membrane‐based fuel cells with a specific focus on membrane materials and their innovative fabrication based on chemical vapor deposition (CVD) approaches. These deposition techniques are introduced, as are the potential improvements relating to cell performance, namely proton conductivity and stability. The potential benefits of applying CVD‐based synthesis in the fabrication of polymer electrolytes is also discussed with respect to future fuel cell development.

Innovative Fabrication of Pd/Pd4S Based Highly Active Electrocatalysts for ORR in a Primary Zn-Air Battery

On account of their high theoretical energy density and minimal cost, Zn-air batteries have gotten a lot of interest as a viable energy storage technology. However, the problem of a high overpotential at the cathode because of the slow oxygen reduction reaction (ORR) kinetics persists. Developing an efficient cathode ORR catalyst and exceeding in performance in comparison to the existing and widely utilized Pt-based catalysts is still a formidable challenge. Herein, this study focuses on the design of a Pt-free catalyst, precisely, Pd/Pd4S based electrocatalysts to enhance ORR performance of cathode. The simple encapsulated structure containing nitrogen-doped carbon (N-doped C) coated Pd/Pd4S and CeO2 nanoparticles (Pd-Pd4S/CeO2/N-C) fabricated by a practical and trouble-free approach has a powerful electrochemical ability. Pd-Pd4S/CeO2/N-C displays a virtually identical limited current density to the commercial 20% Pt/C catalysts and better durability under alkaline conditions. Moreover, this work involves the subsequent utilization of Pd-Pd4S/CeO2/N-C in a primary Zn-air battery as the air electrode, where it manifested comparable current density and power density at 0.6 V as furnished by the Pt/C catalyst. Along with this, the primary Zn-air battery system comprising Pd-Pd4S/CeO2/N-C exhibited constant discharge comprising several hours, a specific capacity of 748 mAh gZn −1, and stability at 10 mA cm−2.

Phytochemically Derived Zingerone Nanoparticles Inhibit Cell Proliferation, Invasion and Metastasis in Human Oral Squamous Cell Carcinoma.

Due to its aggressiveness and high mortality rate, oral cancer still represents a tough challenge for current cancer therapeutics. Similar to other carcinomas, cancerous invasion and metastasis are the most important prognostic factors and the main obstacles to therapy for human oral squamous cell carcinoma (OSCC). Fortunately, with the rise of the nanotechnical era and innovative nanomaterial fabrication, nanomaterials are widely used in biomedicine, cancer therapeutics, and chemoprevention. Recently, phytochemical substances have attracted increasing interest as adjuvants to conventional cancer therapy. The ginger phenolic compound zingerone, a multitarget pharmacological and bioactive phytochemical, possesses potent anti-inflammatory, antioxidant, and anticancer activities. In our previous study, we generated phytochemically derived zingerone nanoparticles (NPs), and documented their superior antitumorigenic effect on human hepatoma cells. In the present study, we further investigated the effects of zingerone NPs on inhibiting the invasiveness and metastasis of human OSCC cell lines. Zingerone NPs elicited significant cytotoxicity in three OSCC cell lines compared to zingerone. Moreover, the lower dose of zingerone NPs (25 µM) markedly inhibited colony formation and colony survival by at least five-fold compared to zingerone treatment. Additionally, zingerone NPs significantly attenuated cell motility and invasiveness. In terms of the signaling mechanism, we determined that the zingerone NP-mediated downregulation of Akt signaling played an important role in the inhibition of cell viability and cell motility. Zingerone NPs inhibited matrix metalloproteinase (MMP) activity, which was highly correlated with the attenuation of cell migration and cell invasion. By further detecting the roles of zingerone NPs in epithelial–mesenchymal transition (EMT), we observed that zingerone NPs substantially altered the levels of EMT-related markers by decreasing the levels of the mesenchymal markers, N-cadherin and vimentin, rather than the epithelial proteins, ZO-1 and E-cadherin, compared with zingerone. In conclusion, as novel and efficient phytochemically derived nanoparticles, zingerone NPs may serve as a potent adjuvant to protect against cell invasion and metastasis, which will provide a beneficial strategy for future applications in chemoprevention and conventional therapeutics in OSCC treatment.

Biobased Innovation as a Fashion and Textile Design Must: A European Perspective

Fashion industry investments drive the choice for textile solutions characterized by radical experimentation and a firm commitment to sustainability. In the last five years, textile innovations have been strongly related to biobased textile solutions evolving to become effectively feasible and strategic. The produced qualitative knowledge implementations consider new production patterns, innovative technical and digital know-how, and new consumption scenarios. The directions the industry is tracing may provide new opportunities for future textile development in the circular biobased economy. This paper presents a map of current European practices. It discusses the possible passage through a holistic paradigm that goes beyond the boundaries of the old productive systems to accompany the sector towards a new sustainable and transversal state. It also presents three selected best practices that return the actual context in which the phenomenon occurs. A model is presented to demonstrate how these circular processes of biobased materials production enable more process innovations which are developed through implementing the process itself: companies’ search for rethinking and implementing the traditional practices or designing new ones (as determined by the doctoral research of one of the authors).

Effect of ultrasonic welding process parameters on peel strength of membranes for tents

Ultrasonic welding is a universal, clean, and secure alternative joining method. Alternative joining technologies are used increasingly to fulfill specific functional requirements of the seam, such as fluid impermeability to achieve positive bonding during the assembly of technical textiles. In this research, the effect of important ultrasonic welding parameters on peel strength and weld seam thickness was investigated for flexible and lightweight textile material, which is a valuable innovative hybrid textile for technical applications like architectural, construction, and protective textiles. Three main welding parameters with three different levels were selected based on the preliminary test results of 6 and 12 mm welding widths, and a superimposed type of seam was applied. Light scanning microscopic images were used to examine the effective weld locations and their morphology at the joining interface. The parametric influence of ultrasonic welding technique on-seam quality and their tendencies in the relationship were analyzed. Optimized peel strength yielding parametric levels were also assessed numerically. The result shows that the optimal peel strength value was obtained at a welding speed of 2.318 m/min, power of 119.382 W, and pressure force of 349.729 N for a 12 mm welding width. The weld seam thickness had an inverse relationship with the peel strength, and a higher amount of thickness was reduced to 12 mm welding width than 6 mm. Microscopic cross-sectional image of weld seam indicated that a compressed yarn between the coating material at higher welding power and pressure force in lower welding speed. A nonlinear quadratic numerical model was developed to predict the peel strength, and their results were close to the regressed diagonal line against the actual points. The statistical analysis was carried out to show the significant effect of process parameters on peel strength, whereby the obtained results were statistically significant.

Recent approaches towards bone tissue engineering.

Bone tissue engineering approaches have evolved towards addressing the challenges of tissue mimetic requirements over the years. Different strategies have been combining scaffolds, cells, and biologically active cues using a wide range of fabrication techniques, envisioning the mimicry of bone tissue. On the one hand, biomimetic scaffold-based strategies have been pursuing different biomaterials to produce scaffolds, combining with diverse and innovative fabrication strategies to mimic bone tissue better, surpassing bone grafts. On the other hand, biomimetic scaffold-free approaches mainly foresee replicating endochondral ossification, replacing hyaline cartilage with new bone. Finally, since bone tissue is highly vascularized, new strategies focused on developing pre-vascularized scaffolds or pre-vascularized cellular aggregates have been a motif of study. The recent biomimetic scaffold-based and scaffold-free approaches in bone tissue engineering, focusing on materials and fabrication methods used, are overviewed herein. The biomimetic vascularized approaches are also discussed, namely the development of pre-vascularized scaffolds and pre-vascularized cellular aggregates.

Two-photon polymerization lithography enabling the fabrication of PEDOT:PSS 3D structures for bioelectronic applications.

Conductive 3D platforms have gained increasing attention in bioelectronics thanks to the improvement in the cell-chip coupling. PEDOT:PSS is nowadays widely employed in bioelectronic applications thanks to its electrical and mechanical properties. In this work, an innovative fabrication method for the realization of PEDOT:PSS-based conductive micropillars and 3D cage-like structures is presented, combining two-photon lithography and electrodeposition techniques.