This paper presents a microfluidic chip, equipped with a backflow prevention channel, for both cell culture and the detection of lactate. Realizing the upstream and downstream separation of the culture chamber and detection zone, the system effectively avoids potential contamination of cells from backflowing reagents and buffers. With this separation in place, it is possible to ascertain the lactate concentration in the flowing material, unhindered by cellular contamination. Given the residence time distribution characteristics of the microchannel networks, and the corresponding time-dependent signal detected within the detection chamber, one can determine the lactate concentration as a function of time, leveraging the deconvolution approach. We further examined the suitability of this detection method by observing lactate production in human umbilical vein endothelial cells (HUVEC). In terms of stability, the microfluidic chip shown here performs very well in the quick detection of metabolites and provides continuous function for more than a few days. This work unveils fresh insights into pollution-free, high-sensitivity cell metabolism detection, promising broad applicability in cellular analysis, drug screening, and disease diagnosis.
Piezoelectric print heads, with their diverse applications, are employed to manipulate a wide range of specialized fluids. Therefore, the fluid's volumetric flow rate at the nozzle dictates the mechanism of droplet formation. This knowledge is used to design the PPH's drive waveform, to control the volume flow rate at the nozzle, and to ultimately improve droplet deposition quality. Through the iterative learning process and the equivalent circuit model for PPHs, we devised a waveform design method for controlling the flow rate volume at the nozzle. microwave medical applications The experimental results validate the ability of the proposed method to accurately control the volumetric flow rate of the fluid exiting the nozzle. To ascertain the practical implementation value of the methodology, we developed two drive waveforms aimed at suppressing residual vibration and producing droplets of reduced size. The proposed method boasts excellent practical applicability, as evidenced by the exceptional results.
Due to its ability to exhibit magnetostriction within a magnetic field, magnetorheological elastomer (MRE) has substantial potential for application in sensor device development. Many existing works, unfortunately, have focused on the investigation of MRE materials possessing a low modulus (below 100 kPa), potentially hindering their use in sensors due to their reduced lifespan and durability. This research endeavors to produce MRE materials with a storage modulus surpassing 300 kPa, increasing both the magnitude of magnetostriction and the resultant normal force. In order to reach this target, MREs are crafted from diverse compositions of carbonyl iron particles (CIPs), in particular, those containing 60, 70, and 80 wt.% CIP. As the concentration of CIPs escalates, a corresponding increase in magnetostriction percentage and normal force increment is observed. Employing 80 weight percent CIP yielded a magnetostriction of 0.75%, a superior result compared to the magnetostriction achieved in previously reported moderate-stiffness MRE materials. As a result, the midrange range modulus MRE, developed in this work, is able to abundantly produce the required magnetostriction value and might be integrated into the design of innovative sensor technologies.
Nanofabrication often employs lift-off processing as a standard method for pattern transfer. Electron beam lithography now has a broader range of possibilities for pattern definition, thanks to the emergence of chemically amplified and semi-amplified resist systems. A reliable and easy-to-implement lift-off method for dense nanostructured designs is reported within the CSAR62 system. The pattern of gold nanostructures, fabricated on silicon, is determined by a single layer of CSAR62 resist. The process streamlines the pathway for defining patterns in dense nanostructures, encompassing varied feature sizes and a gold layer up to a thickness of 10 nm. Successful implementation of the patterns created by this process has been observed in metal-assisted chemical etching.
Third-generation semiconductors, particularly gallium nitride (GaN) on silicon (Si), are the subject of this paper's exploration of their rapid development. The architecture's potential for high-volume production is underpinned by its low cost, large size, and its compatibility with CMOS fabrication processes. Therefore, a number of enhancements have been recommended for the epitaxy structure and high electron mobility transistor (HEMT) process, in particular pertaining to the enhancement mode (E-mode). The 200 mm 8-inch Qromis Substrate Technology (QST) substrate was instrumental in IMEC's 2020 advancements in breakdown voltage, reaching a notable 650 V. Subsequently, incorporating superlattice and carbon doping techniques, IMEC elevated the breakdown voltage to 1200 V in 2022. In 2016, IMEC's strategic choice to utilize VEECO's metal-organic chemical vapor deposition (MOCVD) for GaN on Si HEMT epitaxy, with a three-layer field plate, led to an improvement in dynamic on-resistance (RON). In 2019, Panasonic's HD-GITs plus field version played a key role in the effective enhancement of dynamic RON. These enhancements have improved both the reliability and the dynamic RON.
Optofluidic and droplet microfluidic applications employing laser-induced fluorescence (LIF) have spurred the demand for improved understanding of the heating effects produced by pump laser excitation and refined temperature monitoring within these confined microsystems. A broadband, highly sensitive optofluidic detection system enabled the first observation of Rhodamine-B dye molecules displaying both standard photoluminescence and a blue-shifted emission. 3-Methyladenine cost We establish that the pump laser beam interacting with dye molecules embedded within the low thermal conductivity fluorocarbon oil, a prevalent carrier medium in droplet microfluidics, is the origin of this observed phenomenon. The temperature-dependent fluorescence intensities of Stokes and anti-Stokes exhibit a constant value up to a critical temperature, after which they decrease linearly. The thermal sensitivity is -0.4%/°C for Stokes and -0.2%/°C for anti-Stokes emission. Experimental results showed that a 35 mW excitation power corresponded to a temperature transition of approximately 25 degrees Celsius. Conversely, a smaller excitation power of 5 mW resulted in a transition temperature of roughly 36 degrees Celsius.
Recent years have seen a rising emphasis on droplet-based microfluidics as a microparticle fabrication tool, attributed to its proficiency in exploiting fluid mechanics for generating materials with a narrow size spectrum. This procedure, additionally, presents a controllable method for shaping the composition of the synthesized micro/nanomaterials. Several polymerization techniques have been utilized to produce molecularly imprinted polymers (MIPs) in particle form, with numerous applications across the disciplines of biology and chemistry. Nevertheless, the conventional method, namely the creation of microparticles via grinding and sieving, typically results in limited precision regarding particle size and distribution. For the production of molecularly imprinted microparticles, droplet-based microfluidics serves as an attractive and viable alternative approach. This mini-review focuses on recent examples demonstrating how droplet-based microfluidics can be utilized to create molecularly imprinted polymeric particles for applications within chemical and biomedical sciences.
By combining textile-based Joule heaters with advanced multifunctional materials, meticulously optimized designs, and novel fabrication methods, a new paradigm for futuristic intelligent clothing systems has been established, particularly in the automotive domain. The application of 3D-printed conductive coatings in car seat heating systems is expected to yield further advantages over traditional rigid electrical components, specifically in providing tailored shapes, increased comfort, enhanced feasibility, greater stretchability, and improved compactness. extrahepatic abscesses In connection with this, we report a novel heating method for vehicle seat fabrics that leverages the application of smart conductive coatings. Multi-layered thin films are coated onto fabric substrates with the aid of an extrusion 3D printer, thereby optimizing integration and facilitating processes. A key component of the developed heater unit is the two main copper electrodes, often called power buses, and the three identical carbon composite heating resistors. Electrode subdivision is used to create the connections between the copper power bus and carbon resistors, which is vital for electrical-thermal coupling. To forecast the thermal response of the examined substrates under varying designs, finite element models (FEM) are constructed. It has been observed that the optimal design effectively addresses the critical shortcomings of the initial design, specifically regarding temperature regulation and overheating. Different coated samples are subject to a thorough examination which includes SEM analysis of morphology and complete characterizations of thermal and electrical properties. This approach allows for the identification of significant material parameters, and ensures confirmation of print quality. Printed coating designs are found to have a substantial impact on energy conversion and heating, as established by a combination of finite element modeling and experimental evaluation. Our initial prototype, having undergone significant design improvements, achieves complete compliance with the automotive industry's standards. Smart textiles, employing multifunctional materials and printing technology, can offer an efficient heating solution that substantially improves the comfort levels of both designers and end-users.
Non-clinical drug screening is being revolutionized by the emergence of microphysiological systems (MPS) technology for the next generation.