Microfluidic technology permits the miniaturization of chemical analytical methods that are traditionally undertaken using benchtop equipment in laboratory environment. When applied to environmental monitoring, these "lab-on-chip" systems could allow high-performance analysis be performed situ over distributed sensor networks with large numbers measurement nodes. Here we present first a new generation microfluidic sufficient performance and robustness for deployment natural waters. The...

A rapid and low-cost technique is presented for the fabrication of optical quality microfluidic devices in poly(methyl methacrylate) (PMMA) or cyclic olefin copolymer (COC). When polymer are manufactured by prototyping techniques, such as micromilling, surface roughness typically region hundreds nanometres reducing overall efficiency many microfluidic-based systems. Here we demonstrate a novel solvent vapour treatment that used to irreversibly bond chips while simultaneously channel...

We have designed, built, tested, and deployed an autonomous in situ analyzer for seawater total alkalinity. Such analyzers are required to understand the ocean carbon cycle, including anthropogenic dioxide (CO2) uptake mitigation efforts via monitoring, reporting, verification of removal through alkalinity enhancement. The microfluidic nature our instrument makes it relatively lightweight, reagent efficient, amenable use on platforms that would carry long-term deployments. Our performs a...

Abstract Using environmental DNA (eDNA) to monitor biodiversity in aquatic environments is becoming an efficient and cost-effective alternative other methods such as visual acoustic identification. Until recently, eDNA sampling was accomplished primarily through manual methods; however, with technological advances, automated samplers are being developed make easier more accessible. This paper describes a new sampler capable of self-cleaning multi-sample capture preservation, all within...

The design, fabrication, analysis and characterisation of a continuous flow, microfluidic absorption cell detection system is described. A low cost optical illumination method integrated with simple system. Nitrite detected at nM concentration using the Griess reaction. device based on novel scheme channels made from tinted PMMA. An absorbance path length 25 mm enables nitrite to be 50 10 μM limit 14 nM. was used characterise reaction kinetics maximum sample resolution. In this report detect...

We present a microfluidic apparatus and method for the measurement of asphaltene content in crude-oil samples. The is based on an optical absorption technique, where it was established that coloration correlated linearly with weight content. initial absorbance oil measured, asphaltenes are removed from by addition n-alkane, leading to flocculation subsequent filtration. deasphalted (maltenes) then revealed change absorbance. densities conventional results (e.g., ASTM D6560) 38 samples around...

Interphase fluorescence in situ hybridisation (FISH) is a sensitive diagnostic tool used for the detection of alterations genome on cell-by-cell basis. However, cost-per-test and technical complexity current FISH protocols have slowed its widespread utilisation clinical settings. For many cancers, lack cost-effective informative method has compromised quality life patients. We present first demonstration microchip-based protocol, coupled with novel to immobilise peripheral blood mononuclear...

We present a reliable technique for irreversibly bonding chemically inert Viton® membranes to PMMA and COC substrates produce microfluidic devices with integrated elastomeric structures. is widely used in commercially available valves has several advantages when compared other currently utilised (e.g. PDMS), such as high solvent resistance, low porosity temperature tolerance. The bond strength was sufficient withstand fluid pressure of 400 kPa (PMMA/Viton®) 310 (COC/Viton®) before leakage or...

Fluorescence in situ hybridization (FISH) is a powerful technique for probing the genetic content of individual cells at chromosomal scale. Conventional FISH techniques provide sensitive diagnostic tool detection alterations on cell-by-cell basis; however, cost-per-test terms reagent and highly qualified labour has prevented its wide-spread utilization clinical settings. Here, we address inefficient use with first integrated automated on-chip implementation, one that requires only minutes...

This paper presents a fully integrated RF-powered temperature sensor with non-intermittent operation. The is powered up wirelessly from 915-MHz incident signal using power-efficient RF energy harvester, uses subthreshold ring oscillator that produces highly temperature-dependent oscillation frequency acting as temperature-to-frequency converter, and finally transfers the frequency-modulated to an external reader back scattering. power management circuits are eliminated in designed arrive at...

We describe a novel apparatus and method for rapidly separating measuring four subfractions of crude oil: saturates, aromatics, resins, asphaltenes (SARA). This work is an extension our previous on the microfluidic measurement asphaltene content, where technique was used to separate from oil indirect optical measurement. Here, we extend by adding column chromatography fractionate deasphalted into saturate, aromatic, resin fractions. Saturates are measured refractive index, whereas...

We describe a microfluidic apparatus and method for performing asphaltene yield measurements on crude oil samples.

In this paper, we describe a microfluidic approach for measuring the solubility of asphaltenes in sample crude oil. The parameter is an important property assessing stability oils and mixtures, particularly when blending different or adding diluents. A range solvent–precipitant mixtures are added to oil, which modifies native properties, degree asphaltene precipitation monitored by change optical absorbance each chosen solvent volume fraction. profiles acquired hours compared conventional...

We present two microfluidic architectures (continuous flow and multiplexed stop flow) for miniaturized colorimetric nutrient sensors. These systems are compared with respect to the temporal response (for optimization of sampling rate) reduction reagent consumption. The continuous-flow system is capable a rate 60 samples·h–1, limited by Taylor dispersion. novel stop-flow (MSF) microsystem architecture not A demonstration MSF consisting channels presented. This requires 12.6 s load each sample...

Abstract A novel type of microfluidic absorbance cell is presented here that inlays black poly(methyl methacrylate) (PMMA) into a clear PMMA substrate to realize an isolated optical channel with microlitre volumes. Optical measurements are frequently performed on devices, offering effective, quick, and robust chemical analysis capabilities small amounts sample. Many lab-on-chip systems utilize micrometer-sized channels analyze liquid samples via light-absorbance measurements, but this...

The conversion of solar energy to chemical useful for maintaining cellular function in photosynthetic algae and cyanobacteria relies critically on light delivery the microorganisms. Conventional direct irradiation a bulk suspension leads non-uniform distribution within strongly absorbing culture, related inefficiencies. study small colonies cells controlled microenvironments would benefit from control over wavelength, intensity, location scale microorganism. Here we demonstrate that...

In situ sensors are needed to further our understanding of phosphate flux dynamics in marine environments during short term events such as tidal cycles, algae blooms and runoff periods. Here, we present a fully automated analyzer based on an inlaid microfluidic absorbance cell technology. The device employs colorimetric spectrophotometry, using the phosphomolybdenum blue (PMB) assay modified by addition polyvinylpyrrolidone (PVP), measure concentrations seawater. Bench top calibrations were...

A continuous flow with reagent injection method on a novel inlaid microfluidic platform for nitrite determination has been successfully developed. The significance of the high-frequency monitoring nutrient fluctuations in marine environments is crucial understanding our impacts ecosystem. Many in-situ systems face limitations data collection and have restricted deployment times due to high consumption. proposed device employs automatic colorimetric absorbance spectrophotometry, using Griess...

When performing genetic analysis on microfluidic systems, labeling the sample DNA for detection is a critical preparation step. Labeling procedures often involve fluorescently tagged primers and PCRs, which lengthen experimental run times introduce higher levels of complexity, increasing overall cost per analysis. Alternatively, on-chip techniques based intercalating dyes permit rapid fragments. However, as noted in literature, stochastic nature dye-DNA complex formation hinders native...