Chip Material Research Articles

Organ-on-Chip Technology for Aerobic Intestinal Host – Anaerobic Microbiota Research

The Aerobic intestinal Host – Anaerobic Microbiota (AHAM) interface is an important tissue barrier in our intestine where the microbiota resides in close proximity and in symbiosis with ourselves: the host. A disturbance in this delicate balance between our cells and the commensal microorganisms is associated with effects on the host's health and/or the microbiota. These host-microbiota interactions are believed to be influenced by several factors, which hampers the study of the effect of a single element exclusively. Organ-on-chips (OoCs), microengineered in vitro cell culture models, aim to mimic the physiologically relevant microenvironment of organs. These OoCs can be used to mimic the AHAM interface and study the host-microbiota interactions in a well-controlled environment. In this review, we summarize existing models for (components of) the AHAM interface and provide an overview of four different AHAM-on-chip systems. Furthermore, we defined challenges that need to be taken in consideration when designing or using an AHAM-on-chip, such as the importance of oxygen modulation, sensors and choice of chip material. It is essential to achieve a balance between the accuracy of representing the in vivo interface and the (technical) attainability of the in vitro AHAM-on-chip. The technological and biological aspects make an AHAM-on-chip extremely complex, which emphasizes the need for a multi-disciplinary team. We believe that standardization and higher throughput systems are crucial to accelerate the development of OoC technology. • Intestinal host-microbiota interactions are complex. • In vitro models allow to study interactions under a well-controlled environment. • To sustain both the aerobic host and anaerobic microbiota, oxygen control is required. • A multi-disciplinary team is crucial to cover technological and biological aspects. • More modular systems will be beneficial to accelerate Organ-on-chip technology.

Vertical green system for gray water treatment: Analysis of the VertiKKA-module in a field test

This work presents a modular Vertical Green System (VGS) for gray water treatment, developed at the Bauhaus-Universität Weimar. The concept was transformed into a field study with four modules built and tested with synthetic gray water. Each module set contains a small and larger module with the same treatment substrate and was fed hourly. A combination of lightweight structural material and biochar of agricultural residues and wood chips was used as the treatment substrate. In this article, we present the first 18 weeks of operation. Regarding the treatment efficiency, the parameters chemical oxygen demand (COD), total phosphorous (TP), ortho-phosphate (ortho-P), total bound nitrogen (TNb), ammonium nitrogen (NH4-N), and nitrate nitrogen (NO3-N) were analyzed and are presented in this work. The results of the modules with agricultural residues are promising. Up to 92% COD reduction is stated in the data. The phosphate and nitrogen fractions are reduced significantly in these modules. By contrast, the modules with wood chips reduce only 67% of the incoming COD and respectively less regarding phosphates and the nitrogen fraction.

Determination of acrylamide by a quartz crystal microbalance sensor based on nitrogen-doped ordered mesoporous carbon composite and molecularly imprinted poly (3-thiophene acetic acid) with gold nanoparticles

In this study, a quartz crystal microbalance (QCM) sensor based on nitrogen-doped ordered mesoporous carbon modified-AuNPs (NOMC-Au) modified layer and cross-linked 3-thiopheneacetic acid functionalized AuNPs ([email protected]) imprinted layer was developed for the detection of acrylamide as a hazardous substance in thermal processing. The composite modification layer formed by NOMC-Au was used as support material for QCM gold chips (AuE), and [email protected] were then introduced to the highly selective imprinting modification layer by electropolymerization using propionamide as a template. The use of [email protected] based molecularly imprinted polymer (MIP) on QCM was also evaluated and optimized, and the data were compared with non-imprinted polymer (NIP) and MIP/AuE chip layers. Results showed that a highly crosslinked three-dimensional reticular imprinted layer improved the acrylamide signals in the range of 0.08 ng/mL −100.0 ng/mL, and the sensor was suitable for food samples analysis at concentrations as low as 5.1 pg/mL. The proposed QCM sensor is very useful for future selective and sensitive detection of acrylamide in food samples.

Experimental Validation on the Industrial Panel-Level Process for Producing Solid-State EGFET Sensor Chips

This article presents the experimental validations on an industrial panel-level produced solid-state multisensor for simultaneously pH, electrical conductivity (EC), and temperature detection of solution. Indium tin oxide (ITO) is adopted as the sensing material of the sensor chip due to its good ion selectivity, EC, and linear temperature coefficient of resistance (TCR) characteristics. Meanwhile, thin film deposited Ag/AgCl reference electrode is produced surrounding the sensing electrode to enhance the sensing performance. The sensing chip is produced in the glass substrate and is directly connected to the integrated circuit via a commercial USB-C flexible wire. The experimental results prove that the developed integrated sensor exhibits a high acidity response of 0.1 V/pH ranging from pH 2 to 13. The measured sensitivity is 0.9/°C for temperature detection with a high linearity of 0.9999 and 0.07 V/mS for solution conductivity with the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}$ </tex-math></inline-formula> -squared value of 0.9993. The sensing performance of the developed chips is also evaluated by measuring the urine samples of the five volunteers after drinking water, coffee, and beer, respectively. The measured results are also compared with commercial sensors. The developed integrated sensor has shown its potential for rapid and high performance for detecting the pH, ionic strength, and temperature in solution samples.

Self-loading microfluidic platform with ultra-thin nanoporous membrane for organ-on-chip by wafer-level processing

Embedded porous membranes are a key element of various organ-on-chip systems. The widely used commercial polymer membranes impose limits with regard to chip integration and thinness. We report a microfluidic chip platform with the key element of a monolithically integrated, ultra-thin (700 nm) nanoporous membrane made of ultra-low-stress (&lt;35 MPa) SixNy for culturing and testing reconstructed tissue. The membrane is designed to support various in vitro tissues including co-cultures and to allow passage of molecules but not of cells. A digital laser write method was used to produce nanopores with deterministic but highly flexible positioning within the membrane. A thin layer of photoresist was exposed by accumulation of femtosecond pulses for local two-photon polymerization, which allowed nanopores as small as 350 nm in diameter to be generated through the membranes in a subsequent plasma etch process. The fabricated membranes were used to separate a microfluidic chip into two compartments, which are connected to the outside by microchannel structures. With unique side inlets for fluids, all cells are exposed to identical flow velocities and shear stresses. With the hydrophilic nature of chip materials the self-loading seeding is controlled bottom-up by capillary forces, which makes the seeding procedure homogeneous and less dependent on the operator. The chip is designed to allow fabrication by wafer-level MEMS manufacturing technologies without critical assembly steps, thereby promoting reproducibility and scale-up of fabrication. In order to establish a fully functional test system to be used in a lab incubator, a holder for the bare chip was designed and 3D-printed with additional elements for gravity driven pumping. In order to mimic physiological conditions, the holder was designed to provide not only media delivery but also appropriate shear stress to the tissue. To prove usability, murine microvascular endothelial cells (muMEC) were seeded on the membrane within the chip. Cell compatibility was confirmed after 3 days of dynamic cultivation using fluorescence live/dead assays. Cultivation proved to be reproducible and led to confluent layers with cells preferentially grown on nanoporous areas. The system can in future be cost effectively manufactured in larger quantities in MEMS foundries and can be used for a wide variety of in vitro tissues and test scenarios including pumpless operation within cell incubator cabinets.

Influence of the Geometrical Features of the Cutting Edges of Abrasive Grains on the Removal Efficiency of the Ti6Al4V Titanium Alloy.

The shape of the cutting blades of the abrasive grains has an influence on the material separation process in the machining zone. The paper analyzes the influence of the geometrical parameters of the abrasive grains (rake angle γ, apex angle ε, opening angle α), as well as width bz and length bb of the cutting zone on the material removal efficiency. The material removal efficiency was determined taking into account the volume of the removed material VG and the volume of lateral piles-up VR. The analyses were carried out on the basis of the results of experimental and simulations using the finite element method. The relationship between the selected geometric parameters characterizing the cutting zone and the coefficient characterizing the efficiency of the material removal process was determined. A strong influence of the opening angle α as well as the width bz and length bb of the cutting zone on the material removal process by abrasive grain was demonstrated. It was observed that the wide cutting edge, and thus the large opening angle α of the grain, reduced the size of the pile-ups and more effectively removed the chip material.

Pengaruh Waktu Perendaman dalam Larutan Ca (Oh)2 0,5% terhadap Karakteristik Keripik Singkong

Cassava (Manihot Utilissima Pohl) is one of the food crops that is quite high in production but is easily damaged. Cassava as a raw material for chips has a weakness, namely it contains a bitter or astringent taste, and after being fried, the texture becomes hard. In addition, during the processing before frying there will be a browning reaction due to the reaction between sugar and protein or amino acids. Soaking cassava in a solution of whiting is an effort to reduce the astringent or bitter taste, improve the texture of the cassava chips to make them more crispy, and prevent the browning reaction. This study aims to determine the effect of the immersion period of cassava slices in 0.5% (Ca(OH)2) solution on several characteristics of the cassava chips produced. The design used was a randomized block design (RAK) with 6 treatment periods of immersion (6 hours, 12 hours, 18 hours, 24 hours, 30 hours and 36 hours) with a concentration of 0.5% Ca(OH)2 solution (w/v). ) and repeated 4 times. Organoleptic testing of color, taste, aroma and crispness was carried out by acceptance test (Hedonic). The results showed that soaking cassava in a 0.5% Ca(OH)2 solution for 30 hours produced cassava chips with the best characteristics based on the assessment of taste, aroma, color and crispness.

Numerical modeling of Ti-6Al-4V alloy orthogonal cutting considering microstructure dependent work hardening and energy density-based failure behaviors

Numerical modeling of the cutting process provides an effective method to obtain the micro-scale and instantaneous process information which is difficult to be measured by experiments. A new microstructure (grain size) dependent work hardening plastic (JCM-ms) model was developed to characterize the effect of grain refinement on the cutting process. An energy density-based failure law was applied to control the chip formation and material removal mechanisms ahead of the cutting edge. Orthogonal cutting experiments with different edge radii and uncut chip thickness values for Ti-6Al-4V alloy were carried out to validate the finite element (FE) simulation results. The simulation results were thoroughly validated by the measured principal and thrust forces, segmented chip morphology, and the grain refinement within the machined surface layer. The distribution of grain refinement of the chips and machined surface agreed well with the experimental results. The positions of stagnation points with different edge radii and uncut chip thickness values were measured by the FE simulation results. The variation of surface morphology along the speed direction with larger edge radius is related to the variation of the stagnation points, which will affect the ratio of material being compressed to the machined surface by the tool, during the formation of the adiabatic shear band. The degree of the subsurface shear deformation determines the final distribution of the micro-hardness. Larger shear displacement at the top surface will lead to thicker layer of grain refinement. Residual stresses along the depth from machined surface are mainly related to the displacement normal to the machined surface. The height of the stagnation point is in proportion to the peak compressive stresses induced by the material flow ahead of cutting edge for different conditions. This work provides an effective method to characterize the forces, grain refinement and surface integrity for the orthogonal cutting of Ti-6Al-4V alloy.

Formulation of research and development strategy by analysing patent portfolios of key players the semiconductor industry according to patent strength and technical function

Silicon wafer is the base material of chips and is an important manufacturing technology in semiconductor industry. This research conducts international patent analysis of five major patentees, SUMCO, Shin-Etsu, GlobalWafers, Siltronic, and SK Siltron, also the top five global silicon wafer manufacturers in the world, in order to get research and development strategy.Qualitative and quantitative analysis of technology and means on entire industry as well as individual companies are visualized by technology means matrix, comprehensiveness, and relative patent advantage index. Two categories of indicators of “Patent Portfolio Strength” and “Patented Technology Strength” are calculated, and the patent portfolios of assignees are shown on 2D map.The results demonstrated by taking the GlobalWafers as an example to formulate its R&D strategy, it is lack of patent at manufacturing apparatus, raw material manufacturing, and inspection method, and lack of function objective at melt level, crystallographic, and crucible improvement. These may be the points of breaking through technical barriers. It is good suggestion to increase the average number of independent claims and the ratio of PCT applications to improve the quality of international patent portfolios. The advice from patent technology strength analyses is that it needs to develop more advanced technology.

Advances in Organ-on-a-Chip Materials and Devices

The organ-on-a-chip (OoC) paves a way for biomedical applications ranging from preclinical to clinical translational precision. The current trends in the in vitro modeling is to reduce the complexity of human organ anatomy to the fundamental cellular microanatomy as an alternative of recreating the entire cell milieu that allows systematic analysis of medicinal absorption of compounds, metabolism, and mechanistic investigation. The OoC devices accurately represent human physiology in vitro; however, it is vital to choose the correct chip materials. The potential chip materials include inorganic, elastomeric, thermoplastic, natural, and hybrid materials. Despite the fact that polydimethylsiloxane is the most commonly utilized polymer for OoC and microphysiological systems, substitute materials have been continuously developed for its advanced applications. The evaluation of human physiological status can help to demonstrate using noninvasive OoC materials in real-time procedures. Therefore, this Review examines the materials used for fabricating OoC devices, the application-oriented pros and cons, possessions for device fabrication and biocompatibility, as well as their potential for downstream biochemical surface alteration and commercialization. The convergence of emerging approaches, such as advanced materials, artificial intelligence, machine learning, three-dimensional (3D) bioprinting, and genomics, have the potential to perform OoC technology at next generation. Thus, OoC technologies provide easy and precise methodologies in cost-effective clinical monitoring and treatment using standardized protocols, at even personalized levels. Because of the inherent utilization of the integrated materials, employing the OoC with biomedical approaches will be a promising methodology in the healthcare industry.

Generation of Multicue Cellular Microenvironments by UV-Photopatterning of Three-Dimensional Cell Culture Substrates

The extracellular matrix is an important regulator of cell function. Environmental cues existing in the cellular microenvironment, such as ligand distribution and tissue geometry, have been increasingly shown to play critical roles in governing cell phenotype and behavior. However, these environmental cues and their effects on cells are often studied separately using in vitro platforms that isolate individual cues, a strategy that heavily oversimplifies the complex in vivo situation of multiple cues. Engineering approaches can be particularly useful to bridge this gap, by developing experimental setups that capture the complexity of the in vivo microenvironment, yet retain the degree of precision and manipulability of in vitro systems. This study highlights an approach combining ultraviolet (UV)-based protein patterning and lithography-based substrate microfabrication, which together enable high-throughput investigation into cell behaviors in multicue environments. By means of maskless UV-photopatterning, it is possible to create complex, adhesive protein distributions on three-dimensional (3D) cell culture substrates on chips that contain a variety of well-defined geometrical cues. The proposed technique can be employed for culture substrates made from different polymeric materials and combined with adhesive patterned areas of a broad range of proteins. With this approach, single cells, as well as monolayers, can be subjected to combinations of geometrical cues and contact guidance cues presented by the patterned substrates. Systematic research using combinations of chip materials, protein patterns, and cell types can thus provide fundamental insights into cellular responses to multicue environments.

Generation of Multicue Cellular Microenvironments by UV-photopatterning of Three-dimensional Cell Culture Substrates.

The extracellular matrix is an important regulator of cell function. Environmental cues existing in the cellular microenvironment, such as ligand distribution and tissue geometry, have been increasingly shown to play critical roles in governing cell phenotype and behavior. However, these environmental cues and their effects on cells are often studied separately using in vitro platforms that isolate individual cues, a strategy that heavily oversimplifies the complex in vivo situation of multiple cues. Engineering approaches can be particularly useful to bridge this gap, by developing experimental setups that capture the complexity of the in vivo microenvironment, yet retain the degree of precision and manipulability of in vitro systems. This study highlights an approach combining ultraviolet (UV)-based protein patterning and lithography-based substrate microfabrication, which together enable high-throughput investigation into cell behaviors in multicue environments. By means of maskless UV-photopatterning, it is possible to create complex, adhesive protein distributions on three-dimensional (3D) cell culture substrates on chips that contain a variety of well-defined geometrical cues. The proposed technique can be employed for culture substrates made from different polymeric materials and combined with adhesive patterned areas of a broad range of proteins. With this approach, single cells, as well as monolayers, can be subjected to combinations of geometrical cues and contact guidance cues presented by the patterned substrates. Systematic research using combinations of chip materials, protein patterns, and cell types can thus provide fundamental insights into cellular responses to multicue environments.

A Temperature-Dependent Cauer Model Simulation of IGBT Module With Analytical Thermal Impedance Characterization

In pursuit of high power density and high reliability of power converters, the junction temperature of power devices becomes an essential indicator for heath condition monitoring and thermal management. Particularly under high-temperature operating conditions, the temperature-dependent thermal properties of the chip and ceramic materials must be incorporated to enhance the prediction accuracy. In this article, an improved temperature-dependent Cauer-type thermal network of insulated-gate bipolar transistor (IGBT) module is established. The temperature dependence of thermal parameters for the chip layer and ceramic layer is meticulously considered. More importantly, finite-element method (FEM) simulation is used to yield the heat flux curve of the power module at the center line in order to better imitate the real heat-spreading scenario. In this way, the effective heat transfer area of each layer can be calculated accurately and analytically. By this analytic method, the temperature-dependent thermal impedance can be efficiently determined. Compared with prior-art fully FEM-based temperature-dependent thermal impedance characterization method, the method proposed in this article reduces the FEM simulation time cost approximately 20 times under the same computing hardware facilities and considerably simplifies the parameter extraction process. Finally, experimental results based on two commercial IGBT modules successfully validate the usefulness, effectiveness, and accuracy of the proposed thermal network model.

Roughness maps to determine the optimum process window parameters in face milling

Some industrial applications require structured surfaces with high roughness values to ensure their functionality (Ra > 1 µm, Rmax < 30 µm). In order to obtain these structured surfaces with high roughness values, face milling operation is commonly used in aluminium components employed in the automotive and aeronautical sectors. Polycrystalline diamond insert tools (PCD) are widely used to obtain those structured surfaces. However, one of the major drawbacks of using face milling is that the roughness presents a high variation across the width of cut. Nevertheless, it is possible to mitigate these variations by (i) modifying the micro-geometry of the inserts, (ii) displacing each tooth by small axial amounts from their nominal positions or (iii) varying the feed rate. Frequently, the definition of those parameters is carried out employing trial-and-error strategies, with consequent cost and time penalties. In this research work, roughness maps have been developed as a novel optimisation tool to define the micro-geometry of the PCD inserts, their axial position in the tool and the feed rate, reducing the time to design new cutting tools for face milling. The roughness maps are determined based on roughness indicators calculated from 3D face milled surfaces that are modelled as a split signal in two components: (i) the kinematic movements of the cutting edge and its geometry, and (ii) a novel approach considering the stochastic roughness, which embraces the chip removal process, material defects or vibrations. The model is validated by experimental face milling tests on A-356 aluminium alloy, showing good agreement with experimental results.

Effect of micro-grooved texture on cutting performance of tool under dry condition

To clarify the anti-adhesive properties of the textured tool, two types of micro-grooved textures were fabricated on the tool rake face. The cutting tests were conducted on aluminum alloys under no lubrication condition. Experimental results showed that the cutting force, tool–chip friction coefficient, and surface wear of the P_1 textured tool decreased. However, noticeable disadvantages were observed in samples with other textures. Detailed research indicated that the chip material (Al alloy) was easy to squeeze into and clog in the micro-grooved texture, due to low hardness and high ductility. In contrast, the cutting force, tool–chip interfacial friction, and wear of steel samples with T_1, T_2, and P_2 textures were all greater than that of the nontextured tool. The difference observed in these various textures signifies the importance of the small geometric size of the surface texture in the P_1 texture. Thus, an improvement of tool anti-adhesion with aluminum alloy material was obtained under dry cutting conditions.

Modeling and simulation of radiation effects in nanometric volumes of silicon and water

Understanding the effects of particle radiation in nanoscale electronic materials and biological materials is particularly important for future long-term space flights, nuclear medicine and nuclear power plants. Heavy charged particles arriving among galactic cosmic rays have powerful damaging actions when they pass through the electronic devices and biological objects. The present study is focused on the Monte Carlo modeling of stochastic energy depositions in charged particle tracks and calculation of absorbed energy within small sample (200 nm) of silicon and liquid water. The silicon is widely used material for memory chips, computer processors, transistors, and all other electronics. The most common biomaterial is liquid water, which accounts for 60-90% of all living organisms. The applied simulation technique is based on the Geant4 Monte Carlo transport code, which shows good agreement with experimental cross sections for dosimetry and nano-dosimetry measurements. The calculations were made for protons and carbon ions with different kinetic energies within a relatively wide range of the Bragg curve and linear energy transfer (LET) values from a few to hundreds of keV/μm. We estimated and compared the distribution of energy deposition events and production of reactive chemical species within nanometric volumes of silicon and water after irradiation. We also performed a microdosimetric calculation to estimate LET distribution and nanodosimetric calculation to analyze cluster distributions of ionizations, excitations, elastic collisions and dissociative attachment for electrons corresponds to an interaction with a nonzero energy deposition.

The Analysis of Value Added Products of Jengkol into J Chips in Padang Village, Manggeng District, Aceh Barat Daya Regency

Processing dogfruit into dogfruit chips is one of the potential products to be developed. This study aims to analyze the added value of dogfruit chips using the Hayami method. There are three variables used in this method, namely (1) Output input and price; (2) Revenue and profit and (3) Margin. From the results of the analysis of the production of dogfruit chips, using 10 kg of dogfruit as raw material which produces 7 kg of jengkol chips. The input price for raw material for dogfruit chips, namely dogfruit and edible oil, is Rp. 15,000 per production cycle. The added value obtained is Rp.14,000/kg with the production of 7 kg of dogfruit chips in one production process. Value added ratio 60%.

Topologically Protected Polarization Quantum Entanglement on a Photonic Chip

Quantum entanglement, as the strictly non-classical phenomenon, is the kernel of quantum computing and quantum simulation, and has been widely applied ranging from fundamental tests of quantum physics to quantum information processing. Meanwhile, the topological phase is found inherently capable of protecting physical fields from unavoidable fabrication-induced disorder, which inspires the potential application of topological protection to quantum states. Here, we present the experimental demonstration of topologically protected quantum entangled states on a photonic chip. The process tomography shows that quantum entanglement can be well preserved by the topological states even when the chip material introduces disorder and relative polarization rotation in phase space. Our work links the fields of materials, topological science and quantum physics, opening the door to wide applications of topological enhancement in quantum regime.

Time-efficient fabrication method for 3D-printed microfluidic devices

Recent developments in 3D-printing technology have provided a time-efficient and inexpensive alternative to the fabrication of microfluidic devices. At present, 3D-printed microfluidic systems face the challenges of post-processing, non-transparency, and being time consuming, limiting their practical application. In this study, a time-efficient and inexpensive fabrication method was developed for 3D-printed microfluidic devices. The material for 3D-printed microfluidic chips is Dowsil 732, which is used as a sealant or encapsulant in various industries. The curing time and surface hydrophobicity of the materials were evaluated. The results indicated that the surface of Dowsil 732 is hydrophilic. An optimization model of the direct ink writing method is proposed to establish a time-efficient and accurate fabrication method for microfluidic devices. The results indicate that the optimization model can effectively describe the change trend between printing speed, printing pressure, and channel wall accuracy, and the model accuracy rate exceeds 95%. Three examples—a micromixer, concentration gradient generator, and droplet generator—were printed to demonstrate the functionality and feasibility of the fabrication method.

Evaluation of the utility of the Beta Human Liver Emulation System (BHLES) for CFSAN's regulatory toxicology program

Microphysiological systems (MPS), such as organ-on-a-chip platforms, are an emerging alternative model that may be useful for predicting human physiology and/or toxicity. Due to the interest in these platforms, the Center for Food Safety and Applied Nutrition partnered with Emulate to evaluate the utility of the Beta Human Liver Emulation System (BHLES) for its regulatory science program. Using known hepatotoxic compounds (usnic acid, benzbromarone, tamoxifen, and acetaminophen) and compounds that have no reported human cases of liver toxicity (dimethyl sulfoxide, theophylline, and aminohippurate) the platform's performance was evaluated. Chemical toxicity was assessed by albumin secretion, urea and LDH release, nuclei number, mitochondrial membrane potential, and apoptosis. System/platform performance was evaluated in terms of sensitivity and specificity, power, and variability and repeatability. Chemical interactions with the Chip material were also assessed. Preliminary findings suggested that for the model test compounds selected, the BHLES accurately predicted toxicity, demonstrated high sensitivity and specificity, high power, and low variability. However, some compounds interacted with the Chip material indicating variable exposure levels that should be accounted for when planning experimentation. The details of the evaluation are presented herein.