Label-free DNA analysis system based on Lab-On-Glass technology

Fast and effective diagnostics play an important role in controlling infectious disease by enabling effective patient management and treatment. Here, we present an integrated microfluidic thermoplastic chip with the ability to amplify influenza A virus in patient nasopharyngeal (NP) swabs and aspirates. Upon loading the patient sample, the microfluidic device sequentially carries out on-chip cell lysis, RNA purification and concentration steps within the solid phase extraction (SPE), reverse transcription (RT) and polymerase chain reaction (PCR) in RT-PCR chambers, respectively. End-point detection is performed using an off-chip Bioanalyzer (Agilent Technologies, Santa Clara, CA). For peripherals, we used a single syringe pump to drive reagent and samples, while two thin film heaters were used as the heat sources for the RT and PCR chambers. The chip is designed to be single layer and suitable for high throughput manufacturing to reduce the fabrication time and cost. The microfluidic chip provides a platform to analyze a wide variety of virus and bacteria, limited only by changes in reagent design needed to detect new pathogens of interest.

A point-of-care, diagnostic system incorporating a portable thermal cycler and a compact fluorescent detector for real-time, polymerase chain reaction (PCR) on disposable, plastic microfluidic reactors with relatively large reaction volume (ranging from 10 µL to 100 µL) is described. To maintain temperature uniformity and a relatively fast temperature ramping rate, the system utilizes double-sided heater that features a master, thermoelectric element and a thermal waveguide connected to a second thermoelectric element. The waveguide has an aperture for optical coupling between a miniature, fluorescent reader and the PCR reaction chamber. The temperature control is accomplished with a modified, feedforward, variable structural proportional-integral-derivative controller. The temperature of the liquid in the reaction chamber tracks the set-point temperature with an accuracy of ± 0.1 °C. The transition times from one temperature to another are minimized with controllable overshoots (< 2 °C) and undershoots (< 5 °C). The disposable, single-use PCR chip can be quickly inserted into a thermal cycler/reader unit for point-of-care diagnostics applications. The large reaction chamber allows convenient pre-storing of dried, paraffin-encapsulated PCR reagents (polymerase, primers, dNTPs, dyes, and buffers) in the PCR chamber. The reagents are reconstituted "just in time" by heating during the PCR process. The system was tested with viral and bacterial nucleic acid targets.

Thin and thick film materials are widely used in modern electronic circuits due to their ability to provide miniaturization, high performance, and cost-effective production. Thin film technology involves depositing layers of conductive, resistive, and dielectric materials onto a substrate, typically using methods like vacuum deposition or sputtering. Thick film technology, on the other hand, uses a screen-printing process to deposit paste-like materials onto substrates and is known for its durability and adaptability to harsh environments. Both technologies play crucial roles in designing analog and digital circuits, especially in fields like telecommunications, automotive electronics, and medical devices. The increasing demand for smaller, faster, and more efficient electronic devices has put pressure on the development of high-performance circuits using thin and thick film technologies. A key challenge is optimizing material properties to balance electrical performance, thermal management, and mechanical reliability in both analog and digital circuits. This study explores the design and performance evaluation of analog and digital circuits using thin and thick film materials. Thin film circuits were fabricated using sputtering techniques to deposit layers of resistive and conductive materials with precise thickness control. Thick film circuits were created by screen-printing conductive, resistive, and dielectric pastes onto ceramic substrates. Electrical performance was tested for both types of circuits, focusing on parameters such as resistance, capacitance, and inductance. The thin film circuits demonstrated superior electrical performance with lower parasitic inductance and capacitance, achieving a resistance tolerance of ±1% and a thermal coefficient of resistance (TCR) of ±50 ppm/°C. The thick film circuits, while having slightly higher parasitic values, offered robustness and mechanical stability in high-temperature environments, with TCR values ranging from ±100 to ±250 ppm/°C. Both technologies showed significant promise, with the choice of material depending on the specific application requirements for analog and digital systems.

This paper presents a new self-compensated thermocycler for polymerase chain reaction (PCR), especially used in DNA amplification process requiring precise thermal control. A new design of micro- heaters to improve the thermal uniformity of the PCR chamber using array-type heaters and a self- compensated mechanism is reported. The feature of this design is that structure change or active thermal compensation is not required. Experimental data show that the spatial variation of temperature distribution is less than ldegC in the PCR chamber at annealing temperature. Besides, the area with thermal variation less than 0.5degC is close to 90 % of the working area.

Two kinds of cadmium sulfate (CdS) thin films have been grown at 600 °C onto Si(111) and quartz substrates using femtosecond pulsed laser deposition (PLD). The influence of substrates on the structural and optical properties of the CdS thin films grown by femtosecond pulsed laser deposition have been studied. The CdS thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), photoluminescence (PL) and Raman spectroscopy. Although CdS thin films deposited both on Si(111) and quartz substrates were polycrystalline and hexagonal as shown by the XRD , SEM and AFM results, the crystalline quality and optical properties were found to be different. The size of the grains for the CdS thin film grown on Si(111) substrate were observed to be larger than that of the CdS thin film grown on quartz substrate, and there is more microcrystalline perpendicularity of c-axis for the film deposited on the quartz substrate than that for the films deposited on the Si substrate. In addition, in the PL spectra, the excitonic peak is more intense and resolved for CdS film deposited on quartz than that for the CdS film deposited on Si(111) substrate. The LO and TO Raman peaks in the CdS films grown on Si(111) substrate and quartz substrate are different, which is due to higher stress and bigger grain size in the CdS film grown on Si(111) substrate, than that of the CdS film grown on the amorphous quartz substrate. All this suggests that the substrates have a significant effect on the structural and optical properties of thin CdS films.

Sputtered transparent electrodes for optoelectronic devices: Induced damage and mitigation strategies

Flexible thin film silicon solar modules on heat-resistant transparent flexible substrates are promising to achieve high efficiency by a combination of high-quality silicon thin films and fully monolithic series integration. In this work, performance of superstrate hydrogenated amorphous silicon (a-Si:H) thin film solar cells and modules on flexible glass using boron-doped zinc oxide (BZO) front electrode have been investigated. Compared with conventional glass, BZO thin films on flexible glass exhibited mixed structure of large-sized pyramid and small-sized grain, preferential crystalline orientations of (100) and (110), relatively lower surface roughness and scattering ability. Accordingly, compared with conventional BZO glass, a-Si:H thin film solar cells on flexible BZO glass exhibited a relative increase in open-circuit voltage, fill factor, and efficiency of 2.0, 5.5, and 3.4%, respectively. Finally, ∼50 cm2 flexible a-Si:H thin film solar modules were prepared by fully monolithic series integration using laser scribing, and relatively higher efficiency was achieved by improving thin films uniformity.

This paper reports on the design, fabrication, assembly and testing of amicromachined polymerase chain reaction (PCR) system with pigtailed fibreoptics. Two major designs have been fabricated and tested. The first designuses two optical fibres, one for the projection of light into the chamber andthe other for the collection of the light emitted by a fluorescent dye in thereaction chamber. The second design employs a single optical fibre for thedelivery of light into the PCR chamber, with light now being detected using aphotodiode integrated into the base and walls of the reaction chamber withinthe PCR chip. Tests carried out on both systems have produced promisingresults.

Characterization of thin-film amorphous semiconductors using spectroscopic ellipsometry

TiO2 thin films were prepared on soda lime glass, fused quartz and stainless steel substrates by liquid phase deposition (LPD) method from a (NH4)2TiF6 aqueous solution upon the addition of boric acid (H3BO3), and then calcined at 500oC for 2 h. The prepared films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It was found that the substrates obviously influenced the element composition and microstructure of TiO2 thin films. Except Ti, O and a small amount of F and N elements, which came from the precursor solution, some Si (or Fe) element in the thin films deposited on soda lime glass and quartz substrates (or on stainless steel substrate) was confirmed. The Si (or Fe) element in the thin films could be attributed to two sources. One was from the SiF6 2- ions (or FeF6 2- ions) formed by a reaction between the treatment solution and soda lime glass or quartz (or stainless steel) substrates. The other was attributed to the diffusion of Si (or Fe) from the surface of substrates into the TiO2 thin films after calcination at 500oC. The Si (or Fe) element in the TiO2 thin films could behave as a dopant and resulted in the formation of composite SiO2/TiO2 (or Fe2O3/TiO2) thin films on the substrates.

Amorphous solar cells, the micromorph concept and the role of VHF-GD deposition technique

In order to reveal the influence of substrate on the conductivity change of La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) thin film from the bulk, we prepared LSGM thin films on the sapphire and the quartz substrates by radio frequency magnetron sputtering, and evaluated the crystallinity, the microstructure, and the conductivity. The lattice constant of 0.6 μm thick film was different between the substrates. Compared with the bulk, the lattice constant of the thin film on the sapphire substrate was decreased 1.3%, and that on the quartz substrate was increased 0.7%. The grains in the thin film on the quartz substrate were approximately 0.2 μm in size, and those on the sapphire substrate were approximately 0.1 μm in size. The conductivity was measured at 710 °C by electrochemical impedance spectroscopy. The conductivity of the thin film on the quartz substrate was σ = 2.2 × 10-3 Scm-1 and that on the sapphire substrate was 9.0 × 10-4 Scm-1. The reason why the thin film on the quartz substrate had higher ion conductivity than that on the sapphire substrate can be attributed to the higher density of the grain boundaries which govern the total resistivity of the film on the quartz substrate than that on the sapphire substrate.

This paper presents buckled nitride thin-film encapsulation using anti-adhesion layer assisted transfer technique and BCB/nitride bilayer wrinkling due to elastic property mismatch between the two attached materials. A 900 nm silicon nitride film is deposited on a Si carrier wafer coated with hydrophobic monolayer and then non-patterned nitride film is directly bonded to BCB sealing rings prepared on a target wafer at 250 °C. As bonding and subsequent cooling proceed, shearing force generated by BCB shrinking is applied to the thin nitride film. After bonding, the Si carrier wafer is mechanically separated leaving only nitride membrane inside BCB ring. Thus, self-patterning and self-alignment have been achieved. Interestingly, most of different size nitride membranes are successfully transferred even though large-size ones have partially collapsed or highly deformed. Also, FEM modelings have been carried out to comprehend the formation of the wrinkling of thin elastic film on compliant substrate as well as the debonding of the transfer process of the thin film. It is found that the Young's modulus of compliant substrate is significant to the wavelength of the wrinkle and maximum deflection of the buckled film. The debonding may apply substantial force to the elastic film and thus the nitride membrane needs stabilization time as its shape changes after the debonding.

Analysis of the crystalline characteristics of nc-Si:H thin film using a hyperthermal neutral beam generated by an inclined slot-excited antenna

AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract We have developed a new light-trapping scheme for a thin-film Si stacked module (Si HYBRID PULS module), where a (a-Si:H/transparent interlayer/microcrystalline Si) thin-film was integrated into a large-area solar cell module. An initial aperture efficiency of 13·1% has been achieved for a 910 × 455 mm Si HYBRID PLUS module, which was independently confirmed by AIST. This is the first report of the independently confirmed efficiency of a large-area thin-film Si module with an interlayer. The 19% increase of short-circuit current of this module was obtained by the introduction of a transparent interlayer that caused internal light-trapping. A mini-module was shown to exhibit a stabilized efficiency of 12%. Outdoor performance of a Si HYBRID (a-Si:H / micro-crystalline Si stacked) solar cell module has been investigated for over 4 years with two different kinds of module (top and bottom cell limited, respectively). The HYBRID modules limited by the top cell have exhibited a more efficient performance than the modules limited by the bottom cell, in natural sunlight at noon. Copyright © 2005 John Wiley & Sons, Ltd. REFERENCES 1 Yamamoto K, Suzuki T, Yoshimi M, Nakajima A. Low temperature fabrication of thin film polycrystalline Si solar cell on the glass substrate and its application to the a-Si:H/Polycrystalline Si tandem solar cell. Proceedings of the 25th IEEE Photovoltaic Energy Conversion, Conference, 1996; 661– 664. 2 Yamamoto K, Yoshimi M, Suzuki T, Tawada Y, Okamoto Y, Nakajima A. Very thin film crystalline silicon solar cells on glass substrate fabricated at low temperature. IEEE Transactions Electron Devices 1999; 46: 2041– 2047. 3 Yamamoto K, Yoshimi M, Tawada Y, Okamoto Y, Nakajima A. Cost effective and high-performance thin film Si solar cell towards the 21st century. Solar Energy Materials and Solar Cells 2001; 66: 117– 125. 4 Meier J, et al. On the way towards high-efficiency thin film silicon solar cells by the ‘micromorph’ concept. Proceedings of the Material, Research Society Symposium, Spring Meeting, San Francisco, 1996; 420: 3– 14. 5 Yamamoto K, et al. Novel HYBRID thin film silicon solar cell and module. Proceedings of the 3rd World Conference on Photovoltaic Solar Energy Conversion, 2003; Paper S20B903. 6 Nakajima A, et al. Improvement on actual output power of thin film silicon HYBRID module. Proceedings of the 3rd World Conference on Photovoltaic Solar Energy Conversion, 2003; Paper 60B1104. Citing Literature Volume13, Issue6September 2005Pages 489-494 ReferencesRelatedInformation