Complex Manufacturing Procedures Research Articles

High-performance flexible thermoelectric generator based on silicone rubber and cover with graphite sheet

Harvesting thermal energy through a flexible thermoelectric generator (FTEG) offers an excellent micro-power solution for energizing node sensors in the realm of Internet of Things (IoT) and wearable electronics. Nonetheless, current FTEG suffer from drawbacks including low efficiency, significant thermal resistance, and complex manufacturing procedures. In this study, a high-performance FTEG using silicone rubber was designed and fabricated using a straightforward process. The finite-element method was used to optimize the copper electrode thickness, and the bendable substrate layers with various thermal conductivity were studied for the first time. The copper electrode thickness of 0.1 mm was selected because it offers high flexibility and bendability while still providing a relatively high-power output. The 5 × 5 cm2 FTEG device was fabricated and covered with a bendable substrate. Silicon rubber (0.08 Wm−1K−1), silicon rubber added 5% graphene (0.14 Wm−1K−1), and graphite sheets (15 Wm−1K−1) were used as bendable substrates. The FTEG cover with graphite sheets has a maximum output voltage of 1.1 V under a temperature difference (ΔT) at 65 °C. Its maximum output power is 162.4 mW, corresponding to a power density of 6499.1 µW/cm2 under the same above ΔT. The experimental findings indicated that integrating a bendable substrate with high thermal conductivity and electrical insulation properties enhances the performance of the FTEG.

Solution‐Processable Three‐Dimensional Metamaterials with Ultrahigh Broadband Absorption for Photothermal Electronic Conversion

AbstractMetamaterials are promising candidates for broadband light absorbers, but complex manufacturing procedures with expensive instruments have limited their practical applications. Herein, this work develops an all‐solution‐processed three‐dimensional (3D) metamaterial—based on a gold nanocage (GNC)/silk fibroin (SF) nanocomposite thin film—that achieves near‐unity (>94%) and broadband (350–2000 nm) light absorption. At a low particle density, the film exhibits a typical signal for localized surface plasmon resonance (LSPR) absorption at 856 nm, originating from its hollow geometrical shape of GNCs. In contrast, at high particle densities the films display ultrahigh broadband absorption, even in the non‐LSPR regions. This work attributes this behavior to the highly dense GNCs dispersed uniformly in the SF matrix acting optically as extremely fragmented metallic films, thereby retaining the highly absorptive nature of the metal while strongly suppressing its highly reflective properties. Moreover, the metamaterial absorber displays a desirable broadband‐light‐induced photothermal effect when illuminated with a halogen lamp. Finally, investigations into the photothermal electronic properties of this metamaterial combined with an Al/Si Schottky diode reveal an excellent photoresponse and photostability. The as‐designed systems can function at telecommunication wavelengths longer than the typical operation wavelengths of Si‐based devices. Such 3D metamaterial absorbers can be efficient platforms for various photothermal applications.

Optimized Design and Preparation of Ag Nanoparticle Multilayer SERS Substrates with Excellent Sensing Performance.

Nanoparticle multilayer substrates usually exhibit excellent SERS activity due to multi-dimensional plasmon coupling. However, simply increasing the layers will lead to several problems, such as complex manufacturing procedures, reduced uniformity and poor reproducibility. In this paper, the local electric field (LEF) characteristics of a Ag nanoparticle (AgNP) multilayer were systematically studied through finite element simulations. We found that, on the glass support, the LEF intensity improved with the increase in the layers of AgNPs. However, the maximum LEF could be obtained with only two layers of AgNPs on the Au film support, and it was much stronger than the optimal value of the former. To verify the simulation results, we have successfully prepared one to four layers of AgNPs on both supports with a liquid-liquid interface self-assembly method, and carried out a series of SERS measurements. The experimental results were in good agreement with the simulations. Finally, the optimized SERS substrate, the 2-AgNP@Au film, showed an ultra-high SERS sensitivity, along with an excellent signal uniformity, which had a detection ability of 1 × 10-15 M for the Rhodamine 6G (R6G) and a relative standard deviation (RSD) of 11% for the signal intensity. Our study provides important theoretical guidance and a technical basis for the optimized design and application of high-performance SERS substrates.

Lossless enrichment of trace analytes in levitating droplets for multiphase and multiplex detection

Concentrating a trace amount of molecules from liquids, solid objects, or the gas phase and delivering them to a localized area are crucial for almost any trace analyte detection device. Analytes within a liquid droplet resting on micro/nanostructured surfaces with liquid-repellent coatings can be concentrated during solvent evaporation. However, these coatings suffer from complex manufacturing procedures, poor versatility, and limited analyte enrichment efficiency. Here, we report on the use of an acoustic levitation platform to losslessly concentrate the analyte molecules dissolved in any volatile liquid, attached to solid objects, or spread in air. Gold nanoparticles can be simultaneously concentrated with the analytes in different phases, realizing sensitive, surface-enhanced Raman scattering detection even at attomolar (10−18 mol/L) concentration levels. The acoustic levitation platform-enabled, lossless analyte enrichment can significantly increase the analytical performance of many conventional microsensing techniques.

Engineering hypertrophic cartilage grafts from lipoaspirate for critical-sized calvarial bone defect reconstruction: An adipose tissue-based developmental engineering approach.

Developmental engineering of living implants from different cell sources capable of stimulating bone regeneration by recapitulating endochondral ossification (ECO) is a promising strategy for large bone defect reconstruction. However, the clinical translation of these cell‐based approaches is hampered by complex manufacturing procedures, poor cell differentiation potential, and limited predictive in vivo performance. We developed an adipose tissue‐based developmental engineering approach to overcome these hurdles using hypertrophic cartilaginous (HyC) constructs engineered from lipoaspirate to repair large bone defects. The engineered HyC constructs were implanted into 4‐mm calvarial defects in nude rats and compared with decellularized bone matrix (DBM) grafts. The DBM grafts induced neo‐bone formation via the recruitment of host cells, while the HyC pellets supported bone regeneration via ECO, as evidenced by the presence of remaining cartilage analog and human NuMA‐positive cells within the newly formed bone. However, the HyC pellets clearly showed superior regenerative capacity compared with that of the DBM grafts, yielding more new bone formation, higher blood vessel density, and better integration with adjacent native bone. We speculate that this effect arises from vascular endothelial growth factor and bone morphogenetic protein‐2 secretion and mineral deposition in the HyC pellets before implantation, promoting increased vascularization and bone formation upon implantation. The results of this study demonstrate that adipose‐derived HyC constructs can effectively heal large bone defects and present a translatable therapeutic option for bone defect repair.

Complete System to Generate Clean Water from a Contaminated Water Body by a Handmade Flower-like Light Absorber.

The utilization of solar energy to make human lives better has been one of the primary and green approaches adopted by ordinary people and researchers for decades. This approach has recently gained a lot of attention as a way to tackle clean water scarcity in remote areas. Costly components, complex manufacturing procedures with rarely available equipment, and a surface to condense water vapors are challenges in the way of its application in the required areas. Here, we propose a complete system to solve this problem with a handmade light absorber and a superhydrophilic surface (antifogging) to get vapors back to collect clean water. Our handmade flower-like light absorber stitched by crochet work, the single stitch method, was able to get a decent evaporation rate of 1.75 kg/m2·h in pure water and slightly lower rates of 1.62 and 1.65 kg/m2·h with brine and pond water, respectively. Still, our proposed superhydrophilic coated surface can collect ∼37% more water than the pristine surface. This system has a huge potential for use in rural areas because of multiple key advantages, such as simple technology, readily available low-cost raw materials, and easy fabrication.

Ochre-Based Pigments in the Tablinum of the House of the Bicentenary (Herculaneum, Italy) between Decorative Technology and Natural Disasters

Ochre-based pigments have been employed since the first artistic expressions of mankind, with widespread diffusion during the Roman civilization. Such prominent use influenced their technological development, focused on functional and aesthetic optimization through complex manufacturing procedures. Furthermore, their appearance is also influenced by degradation processes, sometimes driven by natural disasters such as the eruption of Mount Vesuvius in 79 AD, in which yellow ochres of Vesuvian sites were sometimes converted to red by thermal alteration. In this contribution, a multi-analytical approach was adopted based on preliminary non-invasive investigations complemented by laboratory analyses to characterize the painted surfaces of the tablinum of the House of the Bicentenary (Herculaneum) with a particular focus on the ochre-based monochrome backgrounds. The study was aimed at (a) reconstructing the original color scheme of the walls and (b) deciphering the complex decorative techniques adopted by Roman craftsmen. The analytical results allowed testing and defining analytical procedures for the discrimination between the original and converted red pigments. Furthermore, these studies indicated that specific decorative technologies were adopted according to aesthetic, functional, and economic purposes, including the utilization of various qualities of ochre with different compositional and textural properties, and the mixture of ochre pigments with other compounds.

Prediction of shape distortions during forming and welding of a double-curved strip geometry in alloy 718

The finite element method (FEM) has considerably contributed to the development of advanced manufacturing methods for metal structures. The prediction of the final shape of a component is of great interest to the manufacturing industry. The level of demand may increase due to multistage processes. Therefore, including all steps of the manufacturing chain in the simulations is a key to being successful. This has been done for a long time in the stamping industry, which involves sequences of forming, trimming, and springback. However, more complex manufacturing procedures that include assembling of formed parts with forgings and castings via welding have been modelled with simplifications, resulting in a reduced prediction accuracy. In the present study, a double-curved part manufactured from alloy 718 is formed at 20 °C and laser-welded using the bead-on-plate procedure. The coupling of different manufacturing analyses, including cold forming, trimming, result mapping, welding, cooling, and springback, is achieved using LS-DYNA. Additionally, the effect of adding a damage and failure model in the forming simulation is studied. The results of the forming analysis are used as inputs for the material model *MAT_CWM in the welding simulation. The anisotropic thermomechanical properties of alloy 718 are determined at temperatures up to 1000 °C. Encouraging agreement is found between the model predictions and the results of forming and welding tests. The findings underscore the importance of including the material history and accurate process conditions along the manufacturing chain to both the prediction accuracy of shape distortions, and to the potential of the industry.

Laser-induced fragmentation of carbonyl iron as a clean method to enhance magnetorheological effect

Magnetic nanoparticles (NPs) are widely used as additives in magnetorheological (MR) suspensions to enhance their magnetic performance and kinetic stability. The synthesis of NPs is often resolved via chemical routes or complex manufacturing procedures, which require hazardous chemicals and generate waste products. In this study, a clean, laser-mediated strategy known as laser fragmentation in liquids (LFL) is proposed that enables the synthesis of NP-based additives directly from the given MR suspension, with the added advantage of limiting the production of waste during the fabrication process. The carbonyl iron (CI) microparticles dispersed in ethylene glycol were used as both the MR suspension and precursor agent in the production of the nanoscale additive. The size and crystalline structure of the NPs were investigated via TEM and XRD, respectively. The mixture of the MR suspension and laser-synthesized additive notably facilitated the magnetisation of the CI particles, incrementing the MR characteristics and dynamic yield stress values by up to 31% in a low-to-moderate field region, which are important aspects in various field-controlled robotic, damping and torque systems. The concept presented appears to be an effective and clean alternative for fabricating bidispersed MR suspensions through the nanoscale additive approach.

Use of cellulose fibers from wheat straw for sustainable cement mortars

In the present research, an environmentally sustainable material as wheat straw deriving from Apulia region, Southern Italy, was added to cement mortars and characterized by thermal, acoustic, mechanical, and microstructural measurements. The straw and the matrix composition were not modified and the mixture preparation did not require complex manufacturing or expensive procedures. The aim was to obtain a lightweight product for indoor applications using a renewable material from the agro-food industry and adopting a safe and cheap process. The samples with high straw content showed very low thermal conductivities exceeding 0.16 W/mK and good acoustic absorptions in the 500–1000 Hz range. The results were strongly dependent on the porosity of the composites, ascribed to the straw features and to the voids at the cellulose fibers/cement matrix interface. Moreover, preliminary observations of the material stability (microstructural analysis) demonstrated that the conglomerate components did not show detectable effects of degradation.

Facile Fabrication of High-Performance Humidity Sensors by Flash Reduction of GO

Graphene is a promising sensing material that has been widely used for high-performance sensors. However, the development of graphene-based sensing device is limited by complex manufacturing procedures. Here, we report a facile fabrication of humidity sensors by flash reduction of graphene oxides (GO) with the help of a photographic camera flash. The flash treatment triggers a drastic deoxygenation of oxygen functional groups (OCGs) from the GO sheets, which not only restores its conductivity partly but also induces the formation of a highly porous structure. The reduced GO sensor shows high sensitivity at the relative humidity atmosphere of 11%–95%, small hysteresis, rapid response, and enhanced durability. The sensitive mechanism was discussed through the investigation of complex impedance plots. This facile flash reduction strategy holds great promise for chemical-free production of graphene-based sensing devices.

Optofluidic in-fiber interferometer based on hollow optical fiber with two cores.

We demonstrate a novel integrated optical fiber interferometer for in-fiber optofluidic detection. It is composed of a specially designed hollow optical fiber with a micro-channel and two cores. One core on the inner surface of the micro-channel is served as sensing arm and the other core in the annular cladding is served as reference arm. Fusion-and-tapering method is employed to couple light from a single mode fiber to the hollow optical fiber in this device. Sampling is realized by side opening a microhole on the surface of the hollow optical fiber. Under differential pressure between the end of the hollow fiber and the microhole, the liquids can form steady microflows in the micro-channel. Simultaneously, the interference spectrum of the interferometer device shifts with the variation of the concentration of the microfluid in the channel. The optofluidic in-fiber interferometer has a sensitivity of refractive index around 2508 nm/RIU for NaCl. For medicine concentration detection, its sensitivity is 0.076 nm/mmolL-1 for ascorbic acid. Significantly, this work presents a compact microfluidic in-fiber interferometer with a micro-channel which can be integrated with chip devices without spatial optical coupling and without complex manufacturing procedure of the waveguide on the chips.

An Update from the United States National Heart, Lung, and Blood Institute‐funded Production Assistance for Cellular Therapies (PACT) Program: A Decade of Cell Therapy

Recognizing the challenges faced by researchers and clinicians working in the field of cellular therapy, the National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, established the Production Assistance for Cellular Therapies (PACT) program in 2003 and expanded it in 2010. The PACT program provides both clinical product manufacturing support that furthers the mission of NHLBI in the areas of cardiac, lung, and blood diseases and broad support of translational development across all disease areas to serve the entire cell therapy community. The program also provides access to expertise in project management, regulatory affairs, and quality assurance and control. Education initiatives include webinars, cell processing facility-hosted workshops, national workshops, and active participation and leadership within the cell therapy community through collaboration with other cell therapy organizations and academia. So far, over 650 PACT-manufactured cell therapy products have been administered in 32 clinical trials for a range of illnesses and diseases such as acute myocardial infarction, sickle cell disease, and graft-versus-host disease.

Simple and inexpensive microfluidic devices for the generation of monodisperse multiple emulsions

Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology. Polydimethylsiloxane soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. Here, we report the design and fabrication of simple and inexpensive microfluidic devices based on microscope glass slides and pulled glass capillaries, for generating monodisperse multiple emulsions. The advantages of our method lie in a simple manufacturing procedure, inexpensive processing equipment and flexibility in the surface modification of the designed microfluidic devices. Different types of devices have been designed and tested and the experimental results demonstrated their robustness for preparing monodisperse single, double, triple and multi-component emulsions.

Polymer dual ring resonators for label-free optical biosensing using microfluidics

We demonstrate a polymer resonator microfluidic biosensor that overcomes the complex manufacturing procedures required to fabricate traditional devices. In this new format, we show that a gapless light coupling photonic configuration, fabricated in SU8 polymer, can achieve high sensitivity, label-free chemical sensing in solution and high sensitivity biological sensing, at visible wavelengths.

Radiolabeled lipid nanoparticles for diagnostic imaging

Nanoparticles are increasingly being incorporated into the design of diagnostic imaging agents. Significant research efforts have been conducted with one class of lipid nanoparticle (liposomes) radiolabeled with gamma-emitting radionuclides as radiopharmaceuticals for scintigraphic imaging of cancer, inflammation/infection and sentinel lymph node detection. This article reviews the current literature with special emphasis on the clinical studies performed with liposome radiopharmaceuticals for detection of tumors, infectious/inflammatory sites or metastatic lymph nodes. Future uses of liposome radiopharmaceuticals are also described. Characteristics required of the radionuclide, liposome formulation and radiolabeling method for an effective radiopharmaceutical are discussed. A description of the procedures and instrumentation for conducting an imaging study with liposome radiopharmaceutical is included. Clinical studies using liposome radiopharmaceuticals are summarized. Future imaging applications of first- and second-generation radiolabeled liposomes for chemodosimetry and the specific targeting of a disease process are also described. The choice of radionuclide, liposome formulation and radiolabeling method must be carefully considered during the design of a liposome radiopharmaceutical for a given application. After-loading and surface chelation methods are the most efficient and practical. Clinical studies with liposome radiopharmaceuticals demonstrated that a wide variety of tumors could be detected with good sensitivity and specificity. Liposome radiopharmaceuticals could also clearly detect various soft tissue and bone inflammatory/infectious lesions, and performed equal to or better than infection imaging agents that are approved at present. Yet, despite these favorable results, no liposome radiopharmaceutical has been approved for any indication. Some of the reasons for this can be attributed to reports of an unexpected infusion-related adverse reaction in two studies, the requirement of more complex liposome manufacturing procedures, and the adoption of other competing imaging procedures. Continued research of liposome radiopharmaceutical design based on a better understanding of liposome biology, improved radiolabeling methodologies and advances in gamma camera technology is warranted.

The PAMELA silicon tracker

The silicon tracker of the PAMELA apparatus has been assembled and it is ready to fly on-board the Russian satellite Resurs DK for a 3-year mission. The experiment will study, mainly, spectra of particles and antiparticles in cosmic rays. The magnetic spectrometer's primary goal is to precisely measure momenta of charged particles, whose trajectories have been bent by a permanent magnet. The detector is composed of 6 planes of double-sided silicon microstrip detectors, inserted between adjacent modules of a permanent magnet which produces an almost uniform magnetic field inside a rectangular cavity that particles cross. The spatial resolution of the detectors is about 3 μm for the bending coordinate. The development of such detectors required a complex manufacturing procedure in order to preserve the physical performance in a device suitable for a space mission. In the construction phase data originating from both beam tests and simulation helped to check the detector's characteristics and to optimize the achievable spatial resolution. The development and the final assembling of these detectors are described in this paper.

Preliminary studies with recombinant chorionic gonadotropin beta-subunit produced in Escherichia coli for use as an antigen in a birth control vaccine.

Prototype human chorionic gonadotropin (hCG) vaccines based on natural sources are unsuitable for widespread applications due to their complex manufacturing procedures, cost, and carrier-mediated immune suppression. Wistar rats were immunized with alum-adsorbed CG beta (recombinant), CG beta-TT, and nCG beta (native CG beta)-TT, whereas Bonnet monkeys were immunized with only CG beta. The anti-hCG antibody titre in the sera obtained at different time points were quantified by radioimmunoassay. The sera of Wistar rats were characterized in terms of their affinity to hCG, bioneutralization capacity (by inhibition of hCG-induced testosterone production in Leydig cells), and cross-reactivity with human luteinizing hormone, human follicle-stimulating hormone, and human thyroid-stimulating hormone (by direct binding assays). Antigen-binding capacities of sera obtained upon immunization with CG beta were 3,080 +/- 943 ng/ml (n = 6) and 3,993 +/- 1,292 ng/ml (n = 4), respectively, in rats and monkeys. The analysis of data revealed that immunization of rats with CG beta produced antibodies comparable to that of CG beta-TT and nCG beta-TT. The study opens up the possibility of producing pure and highly immunogenic CG beta by a recombinant DNA route, as a consistent source of antigen for birth control vaccine.

Foamed epoxy resin-based lung substitutes.

A variety of materials have been introduced over the years to simulate lung tissue, with both foamed and granulated products being used (Edling, 1944; Alderson et al, 1962; Rogers, 1970; Stacey, 1972; McGinley, 1973; White, 1974; Constantinou, 1978). Unfortunately, many available lung substitutes have imprecise or variable elemental compositions. In addition, complex manufacturing procedures are frequently necessary in order to produce the required material. In this note a range of foamed lung substitutes based on an epoxy resin system are discussed. The substitutes have well defined elemental compositions and radiation interaction characteristics for photons and electrons that closely match those of the lungs. By careful addition of a special foaming agent, the mass density of the final material may be at any derived value within the quoted mass density range of the inflated/deflated lung (260–1050 kg m−3) (International Commission on Radiological Protection (ICRP), 1975). It should be noted that the mat...

Leading pharmaceutical and chemical companies have their NEW ORGANIC CHEMICALS

One of the country's major corporations had developed a product with truly exceptional sales potential. Rather than become involved with complex manufacturing procedures, the company arranged to have Trubek produce this new product at an agreed upon price per pound . . . thus eliminating the need for a very substantial investment in manufacturing facilities . . . permitting them to concentrate on research and marketing . . . and to score one of the greatest merchandising triumphs of recent years. Similar case histories . . . involving some of the leading names in the chemical and pharmaceutical industries . . . have proven the advantages of Trubek's services in producing organic chemicals. For Trubek provides a practical, economical method to get a new organic chemical into production quickly . . · without risking capital . . . and without production headaches for the client company. THE TRUBEK METHOD Based on extensive experience, Trubek has ...