Miniatured dual-field microscope for intelligent Marine algae detection, sizing and counting in a microfluidic chip.

On-site and accurately detecting, sizing and counting living algae are greatly needed under International Ballast Water Convention, yet still challenging due to the lack of miniatured device. In this paper, a miniatured microscope that has both blue view field and fluorescence field was developed. Dual-view-field with one exciting light is achieved by using a beam splitter to direct the light into two mini cameras.

Polymer solution flow transitions and scaling laws for changing contraction ratios in planar constriction microchannels.

Pores scale flows through contractions and expansions are relevant in geoengineering, microfluidics and material processing These flows experience shearing and extensional kinematics near constrictions, where polymer solutions may demonstrate instabilities that arise from the fluid's nonlinear rheological characteristics even in creeping flows. The relative effect of shearing and extension can be controlled by the flow geometry. Following our earlier reports on the constriction length (M.

Predictively designing a linear solid-liquid triboelectric nanogenerator for underwater tactile sensing.

A conventional "design-and-then-test" methodology is employed for the design of a solid-liquid triboelectric nanogenerator (SL-TENG)-based sensor. The problem, however, is that the output is nonlinear with unknown sensitivity before it has been tested. To address this problem, predictively designing an SL-TENG sensor with linear output for underwater application is presented.

Compressive Sponge Electrodes Enabled Highly Sensitive Hybrid-Iontronic Pressure Sensor.

Most iontronic pressure sensors with planar metallic electrodes exhibit significant performance degradation in the medium to high-pressure range. To achieve high sensitivity in a broad sensing range, compressive porous electrodes (CPE) were employed to fabricate an ultrasensitive hybrid-iontronic pressure sensor. The sensor demonstrates an ultrahigh sensitivity of 198,160 kPa, a pressure resolution of 4.

A composite optical filter greenly fabricated for living algae detection.

The integration of optical filtration functionality into a lens and a microfluidic chip represents a promising approach for reducing the size of a microfluidic device. Greenly fabricating a composite polydimethylsiloxane (PDMS) filter (C-filter) with optical amplification function for chlorophyll fluorescence detection was proposed in this work. The core idea is to make the PDMS microfluidic chip as one sub-filter (S-filter) and enable another sub-filter amplification function (F-lens).

Optimization and Comprehensive Characterization of the Microencapsulation Process for Taro Essence.

This study investigated the microencapsulation process of natural taro essence and characterized its physicochemical properties. The effects of core-to-wall ratio, T-20/β-CD mass ratio, and ultrasonic time on encapsulation efficiency were systematically investigated. Optimal conditions, identified through orthogonal experiments, included a core-to-wall ratio of 1:10, a T-20/β-CD mass ratio of 1.

Double-Angling-Subspace Enabled Laser-Induced Fluorescence Method for Determining the Types and Mass Ratio of Marine Microplastics.

Currently, the laser-induced fluorescence method faces challenges in reliably determining the types and mass ratios of marine microplastics due to overlapped fluorescence spectra of different microplastics. To address this issue, this paper proposes a double-angling-subspace (DAS) method to differentiate the overlapped fluorescence spectra. The key idea is to span subspaces with vectors converted by known fluorescence spectra, followed by calculating the angle between vectors and subspaces.

Identification of marine microplastics by a combined method of principal component analysis and random forest for fluorescence spectrum processing.

The severely overlapped laser-induced fluorescence spectra between different microplastics pose significant challenges on fluorescence-based particle identification and quantification. To address this problem, this paper proposes a combined method of principal component analysis (PCA) and random forest (RF) for fluorescence spectrum processing. The key idea is to identify the overlapped PCA scores of the first three principal components of fluorescence spectra by the random forest method.

Microfluidic chip systems for color-based antimicrobial susceptibility test a review.

Clinical bacteria pose a significant public health threat, underscoring the need for reliable and rapid diagnostic methods for early disease detection, which can facilitate patient recovery. Current diagnostic methods for rapid pathogen detection often take hours to days and require numerous reagents and lengthy protocols. Microfluidic chip system offers a promising solution for clinical microbiology detection by reducing detection time with minimal setup and providing a point-of-care solution for patients.

Elasto-inertial instabilities in the merging flow of viscoelastic fluids.

Many engineering and natural phenomena involve the merging of two fluid streams through a T-junction. Previous studies of such merging flows have been focused primarily upon Newtonian fluids. We observed in our recent experiment with five different polymer solutions a direct change from an undisturbed to either a steady vortical or unsteady three-dimensional flow at the T-junction with increasing inertia.

Self-Assembly of Strain-Adaptable Surface-Enhanced Raman Scattering Substrate on Polydimethylsiloxane Nanowrinkles.

Flexible surface-enhanced Raman scattering (SERS) substrates adaptable to strains enable effective sampling from irregular surfaces, but the preparation of highly stable and sensitive flexible SERS substrates is still challenging. This paper reports a method to fabricate a high-performance strain-adaptable SERS substrate by self-assembly of Au nanoparticles (AuNPs) on polydimethylsiloxane (PDMS) nanowrinkles. Nanowrinkles are created on prestrained PDMS slabs by plasma-induced oxidation followed by the release of the prestrain, and self-assembled AuNPs are transferred onto the nanowrinkles to construct the high-performance SERS substrate.

Modification of the electrokinetic motion of microalgae through light illumination for viability assessment.

The viability detection of microalgae with the electrokinetic (EK) technique shows vast applications in the biology and maritime industry. However, due to the slight variations in the EK properties between alive and dead microalgae cells, the accuracy and practicability of this technique is limited. In this paper, the light illumination pretreatment was conducted to modify the EK velocity of microalgae for enhancing the EK difference.

Identification of marine microplastics based on laser-induced fluorescence and principal component analysis.

Although the laser-induced fluorescence method shows great potential for microplastic particle detection, overlapping fluorescence signals make accurate type and proportion identification difficult. This paper presents the identification of marine microplastics based on laser-induced fluorescence and principal component analysis. This method works by measuring the fluorescence spectra of water-containing microplastic samples irradiated with a 405-nm laser, which are then analyzed using the principal component analysis (PCA) method.

Recent Development and Applications of Stretchable SERS Substrates.

Surface-enhanced Raman scattering (SERS) is a cutting-edge technique for highly sensitive analysis of chemicals and molecules. Traditional SERS-active nanostructures are constructed on rigid substrates where the nanogaps providing hot-spots of Raman signals are fixed, and sample loading is unsatisfactory due to the unconformable attachment of substrates on irregular sample surfaces. A flexible SERS substrate enables conformable sample loading and, thus, highly sensitive Raman detection but still with limited detection capabilities.

Electrokinetic Effect of a Two-Liquid Interface within a Slit Microchannel.

This paper presents an investigation of the electrokinetic effect at a two-liquid (immiscible liquid-aqueous solution) interface within a slit microchannel using a three-dimensional (3D) numerical model, with a particular focus on the impact of the surface ζ-potential and liquid phase height on the interface electrokinetic velocity. The findings indicate that the direction of the interface movement depends on the ζ-potentials at the two-liquid interface and the microchannel wall. When the absolute value of the negative ζ-potential at the interface is smaller than that at the wall, the interface moves toward the negative pole of the applied direct current (DC) electric field; conversely, it moves in the opposite direction.

Surface charging and electrophoretic behavior of conductive polymer micro-droplets in conductive polymer liquid solutions.

This study investigates the surface charging and electrophoretic motion of polyethylene glycol-rich (PEG-rich) micro-droplets in dextran-rich solutions or dextran-rich micro-droplets in PEG-rich solutions. The electrophoretic velocities of the droplets were measured in a centimeter-sized chamber under an optical microscope. It was found that the direction of electrophoretic motion of both the PEG-rich droplets and dextran-rich droplets is opposite to the applied electric field, meaning that both the PEG-rich droplets and dextran-rich droplets are negatively charged.

CO laser combined with low-temperature plasma radiofrequency ablation promotes recovery of swallowing function in elderly patients with early glottic carcinoma.

Objective: This study was designed to determine the effect of CO laser combined with low-temperature plasma radiofrequency ablation (LPRA) on swallowing function and prognosis in elderly patients with early glottic laryngeal cancer (GLC).

Methods: The clinical data of 115 elderly patients with early GLC treated in General Hospital of Daqing Oil Field from May 2013 to September 2015 were retrospectively analyzed. These patients were assigned to a research group or control group according to different therapeutic regimen.

In-depth understanding of boosting salinity gradient power generation by ionic diode.

Ionic diodes constructed with asymmetric channel geometry and/or charge layout have shown outstanding performance in ion transport manipulation and reverse electrodialysis (RED) energy collection, but the working mechanism is still indistinct. Herein, we systematically investigated RED energy conversion of straight nanochannel-based bipolar ionic diode by coupling the Poisson-Nernst-Planck and Navier-Strokes equations. The effects of nanochannel structure, charging polarity, and symmetricity as well as properties of working fluids on the output voltage and output power were investigated.

Electrokinetic motion and viability assessment of algae with a polyethylene glycol-dextran interface.

At present, there is still limited report on the electrokinetic (EK) behavior of bioparticles at the interface of an aqueous two-phase system. In this paper, the EK motion and viability assessment of live algae mixed with the NaClO treated dead algae were carried out at the interface formed by polyethylene glycol (PEG)-rich phase and dextran (DEX)-rich phase in a straight microchannel. The experimental results show that both the live and dead algae at the PEG-DEX interface migrate from the negative electrode to the positive electrode, and the EK velocity of live algae at the interface is slightly larger than that of the dead ones with similar diameters.

Electrokinetic transport phenomena in nanofluidics and their applications.

Much progress has been made in the electrokinetic phenomena inside nanochannels in the last decades. As the dimensions of the nanochannels are compatible to that of the electric double layer (EDL), the electrokinetics inside nanochannels indicate many unexpected behaviors, which show great potential in the fields of material science, biology, and chemistry. This review summarizes the recent development of nanofluidic electrokinetics in both fundamental and applied research.

Recent advances in multimode microfluidic separation of particles and cells.

Microfluidic separation of particles and cells is crucial to lab-on-a-chip applications in the fields of science, engineering, and industry. The continuous-flow separation methods can be classified as active or passive depending on whether the force involved in the process is externally imposed or internally induced. The majority of current separations have been realized using only one of the active or passive methods.

Marine Structural Health Monitoring with Optical Fiber Sensors: A Review.

Real-time monitoring of large marine structures' health, including drilling platforms, submarine pipelines, dams, and ship hulls, is greatly needed. Among the various kinds of monitoring methods, optical fiber sensors (OFS) have gained a lot of concerns and showed several distinct advantages, such as small size, high flexibility and durability, anti-electromagnetic interference, and high transmission rate. In this paper, three types of OFS used for marine structural health monitoring (SHM), including point sensing, quasi-distributed sensing, and distributed sensing, are reviewed.

A Fiber Bragg Grating Sensor Based on Cladding Mode Resonance for Label-Free Biosensing.

A fiber-optic biosensing platform based on ultra-narrowband cladding mode resonances was developed on a high-reflectivity fiber Bragg grating (FBG) for targeting biomolecular detection. The multiple cladding modes with a high sensitivity to the refractive index (RI) were excited in the FBG by coupling between the forward-propagating guided core mode of the multimode fiber and the backward-propagating guided cladding mode of the FBG without any damage to the fiber structure or any change to the standard FBG manufacturing process. The full width at half maximum and the Q-factor of the typical cladding mode resonance operation of the proposed sensor are 80 pm and 19,270, respectively, which are better than those of most fiber-optic biosensors reported to date.