Fluid Handling Research Articles

Interrelationships between cotton fiber quality traits and fluid handling and moisture management properties of nonwoven textiles

Cotton fibers represent a sustainable and environmentally responsible raw material for the production of nonwoven textiles which are currently dominated by synthetic fibers derived from petrochemicals. Natural variation in quality parameters such as fineness, length, and strength present a challenge for cotton fiber conversion to yarns and in weaving and knitting for conventional textiles. The grading process for cotton fibers addresses this issue by allowing converters to select fibers suitable for specific woven textile applications. However, there has been little attempt to correlate cotton fiber quality traits with nonwoven textiles performance. This study examined the relationship of cotton fiber quality and fluid handling and moisture management performance properties of nonwoven textiles for personal hygiene and disposable applications. This includes potential end-use in diapers and incontinence products as well as disposable textiles for use in clinical settings. Ten recombinant inbred lines of cotton with a broad distribution of fiber quality traits were selected from a multiparent advanced generation intercross population. Fibers were harvested, converted into nonwoven textiles, and subjected to a series of standardized testing protocols. The results indicated that inferior quality coarse cotton fibers subjected to discount market pricing can be selectively utilized for nonwoven applications that benefit from improved moisture management and fluid handling performance.

Nectar feeding beyond the tongue: hummingbirds drink using phase-shifted bill opening, flexible tongue flaps and wringing at the tips.

Hummingbirds are the most speciose group of vertebrate nectarivores and exhibit striking bill variation in association with their floral food sources. To explicitly link comparative feeding biomechanics to hummingbird ecology, deciphering how they move nectar from the tongue to the throat is as important as understanding how this liquid is collected. We employed synced, orthogonally positioned, high-speed cameras to describe the bill movements, and backlight filming to track tongue and nectar displacements intraorally. We reveal that the tongue base plays a central role in fluid handling, and that the bill is neither just a passive vehicle taking the tongue inside the flower nor a static tube for the nectar to flow into the throat. Instead, we show that the bill is actually a dynamic device with an unexpected pattern of opening and closing of its tip and base. We describe three complementary mechanisms: (1) distal wringing: the tongue is wrung out as soon as it is retracted and upon protrusion, near the bill tip where the intraoral capacity is decreased when the bill tips are closed; (2) tongue raking: the nectar filling the intraoral cavity is moved mouthwards by the tongue base, leveraging flexible flaps, upon retraction; (3) basal expansion: as more nectar is released into the oral cavity, the bill base is open (phase-shifted from the tip opening), increasing the intraoral capacity to facilitate nectar flow towards the throat.

453 Rapid SARS-CoV-2 testing with duplexed recombinase polymerase amplification and a bacteriophage internal control

OBJECTIVES/GOALS: Current COVID-19 rapid molecular tests require cartridge-reader detection, expensive circuitry, and complex microfluidics making the most accurate tests unavailable to the masses. Here we present a rapid molecular diagnostic leveraging isothermal amplification and paper-based microfluidics for a low-cost ultra-sensitive COVID-19 assay. METHODS/STUDY POPULATION: We designed a reverse transcription recombinase polymerase amplification (RT-RPA) assay for the detection of SARS-CoV-2 and bacteriophage MS2 RNA. RT-RPA is a sequence specific, ultrasensitive, rapid isothermal DNA amplification technique that is well suited to home based testing due to its rapid assay time, robustness, ease of use, and readout options. RT-RPA reagents are added to a tube and incubated at 39°C in a fluorometer. Realtime fluorometer data gives results in under 15 minutes. This assay also provides visual detection via lateral flow readout with results in 23 minutes. RESULTS/ANTICIPATED RESULTS: We have developed a rapid multiplexed nucleic acid amplification assay with an internal process control for SARS-CoV-2 using single-pot RT-RPA. We screened 21 primer combinations to select primers that demonstrated excellent performance and target specificity against common respiratory viruses. We demonstrate the ability to multiplex SARS-CoV-2 and MS2 detection, utilizing MS2 as an internal process control for lysis, reverse transcription, amplification, and readout. We show duplexed detection using both fluorescence readout and visual readout using lateral flow strips. Duplexed fluorescence detection shows a limit of detection of 25 copies per reaction. Duplexed lateral flow readout shows a limit of detection of 50 copies per reaction DISCUSSION/SIGNIFICANCE: We developed a duplexed RT-RPA assay for SARS-CoV-2 with fluorescence or lateral flow readout. Our assay does not re-quire expensive reader, circuity, or fluid handling. The low material cost, temperature, and robustness make it ideal for a more accurate home-based COVID-19 diagnostic.

Evaluation of a chitosan dressing in the management of hard-to-heal wounds

Following Isle of Wight NHS Foundation Trust guidelines and with patient consent, 11 patients with chronic wounds of various aetiologies and wound durations were enrolled in a multicentre, clinical 4-week evaluation. Over a 4-week evaluation period, all patients showed a significant improvement in wound healing parameters including average tissue type, condition of periwound skin, patient comfort, exudate levels. The assessments demonstrated a significant decrease in necrotic and sloughy tissue (from >75% at the start of treatment), replaced with healthy granulation and epithelial tissue (>80% by week 4). Significant reduction in pain score was also reported in all patients, with average pain score at the start of the evaluation reducing from 5.8 ± 2.7 to a score of 2.5 ± 1.9 within 3 weeks. The complicated wounds seen in this study were previously non-healing and MaxioCel, with BMG technology, demonstrated both significant clinical improvement and a positive impact on patient quality of life within just 4 weeks, resulting in its addition to the team's woundcare formulary.

Loss of Adgra3 causes obstructive azoospermia with high penetrance in male mice.

The adhesion receptor ADGRA3 (GPR125) is a known spermatogonial stem cell marker, but its impact on male reproduction and fertility has not been examined. Using a mouse model lacking Adgra3 (Adgra3-/- ), we show that 55% of the male mice are infertile from puberty despite having normal spermatogenesis and epididymal sperm count. Instead, male mice lacking Adgra3 exhibited decreased estrogen receptor alpha expression and transient dilation of the epididymis. Combined with an increased estradiol production, this indicates a post-pubertal hormonal imbalance and fluid retention. Dye injection revealed a blockage between the ejaculatory duct and the urethra, which is rare in mice suffering from infertility, thereby mimicking the etiologies of obstructive azoospermia found in human male infertility. To summarize, male reproductive tract development is dependent on ADGRA3 function that in concert with estrogen signaling may influence fluid handling during sperm maturation and storage.

Daphnia-inspired dynamic slippery chemically bonded liquid surface for the active prevention of covalently attached foulant adhesion.

Engineering anti-adhesion coatings always focuses on a specific hierarchy and surface free energy, which passively endures water scouring to wash away the loosely attached foulants. Certain foulants, however, especially those that are highly adhesive or covalently attached on the coatings, cannot be removed off the designed surfaces easily. Inspired by the active self-hunting behavior of the filter-feeding animal Daphnia, herein, we propose a universal antifouling strategy with both passive and active adhesion repellency capabilities. The premise for this protocol is that the as-fabricated liquid-like surface is able to repel the settlement of general foulants upon static conditions. Under steady thermal stimuli, the dynamic liquid-like surface behaves like a boxer with an active prevention ability against highly adhesive foulant adhesion, e.g., proteins, crude oils, and even covalently adhered mussel species. The enhanced biocide-free anti-adhesion performance is attributed to the reversible non-covalent interactions of pollutants in the initial contact with the surface, which was innovatively proved by AFM tapping tests to elucidate the physicochemical interactions between the foulants and coating surfaces. We envision that such an active anti-covalent adhesion surface may have great potential in diverse fields, including marine antifouling, fluid handling and transportation, and energy-harvesting devices.

Acoustofluidics - changing paradigm in tissue engineering, therapeutics development, and biosensing.

For more than 70 years, acoustic waves have been used to screen, diagnose, and treat patients in hundreds of medical devices. The biocompatible nature of acoustic waves, their non-invasive and contactless operation, and their compatibility with wide visualization techniques are just a few of the many features that lead to the clinical success of sound-powered devices. The development of microelectromechanical systems and fabrication technologies in the past two decades reignited the spark of acoustics in the discovery of unique microscale bio applications. Acoustofluidics, the combination of acoustic waves and fluid mechanics in the nano and micro-realm, allowed researchers to access high-resolution and controllable manipulation and sensing tools for particle separation, isolation and enrichment, patterning of cells and bioparticles, fluid handling, and point of care biosensing strategies. This versatility and attractiveness of acoustofluidics have led to the rapid expansion of platforms and methods, making it also challenging for users to select the best acoustic technology. Depending on the setup, acoustic devices can offer a diverse level of biocompatibility, throughput, versatility, and sensitivity, where each of these considerations can become the design priority based on the application. In this paper, we aim to overview the recent advancements of acoustofluidics in the multifaceted fields of regenerative medicine, therapeutic development, and diagnosis and provide researchers with the necessary information needed to choose the best-suited acoustic technology for their application. Moreover, the effect of acoustofluidic systems on phenotypic behavior of living organisms are investigated. The review starts with a brief explanation of acoustofluidic principles, the different working mechanisms, and the advantages or challenges of commonly used platforms based on the state-of-the-art design features of acoustofluidic technologies. Finally, we present an outlook of potential trends, the areas to be explored, and the challenges that need to be overcome in developing acoustofluidic platforms that can echo the clinical success of conventional ultrasound-based devices.

Towards an active droplet-based microfluidic platform for programmable fluid handling.

Droplet-based microfluidic systems have emerged as powerful alternatives to conventional high throughput screening platforms, due to their operational flexibility, high-throughput nature and ability to efficiently process small fluid volumes. However, the challenges associated with performing bespoke operations on user-defined droplets often limit their utility in screening applications that involve complex workflows. To this end, the marriage of droplet- and valve-based microfluidic technologies offers the prospect of balancing the controllability of droplet manipulations and analytical throughput. In this spirit, we present a microfluidic platform that combines the capabilities of integrated microvalve technology with droplet-based sample compartmentalization to realize a highly adaptable programmable fluid handling functionality. The microfluidic device consists of a programmable formulator linked to an automated droplet generation device and storage array. The formulator leverages multiple inputs coupled to a mixing ring to produce combinatorial solution mixtures, with a peristaltic pump enabling titration of reagents into the ring with picoliter resolution. The platform allows for the execution of user-defined reaction protocols within an array of storage chambers by consecutively merging programmable sequences of pL-volume droplets containing specified reagents. The precision in formulating solutions with small differences in concentration is perfectly suited for the accurate estimation of kinetic parameters. The utility of our platform is showcased through the performance of enzymatic kinetic measurements of beta-galactosidase and horseradish peroxidase with fluorogenic substrates. The presented platform provides for a range of automated manipulations and paves the way for a more diverse range of droplet-based biological experiments.

Polymer-based microfluidic device for on-chip counter-diffusive crystallization and in situ X-ray crystallography at room temperature.

Proteins are long chains of amino acid residues that perform a myriad of functions in living organisms, including enzymatic reactions, signalling, and maintaining structural integrity. Protein function is determined directly by the protein structure. X-ray crystallography is the primary technique for determining the 3D structure of proteins, and facilitates understanding the effects of protein structure on function. The first step towards structure determination is crystallizing the protein of interest. We have developed a centrifugally-actuated microfluidic device that incorporates the fluid handling and metering necessary for protein crystallization. Liquid handling takes advantage of surface forces to control fluid flow and enable metering, without the need for any fluidic or pump connections. Our approach requires only the simple steps of pipetting the crystallization reagents into the device followed by either spinning or shaking to set up counter-diffusive protein crystallization trials. The use of thin, UV-curable polymers with a high level of X-ray transparency allows for in situ X-ray crystallography, eliminating the manual handling of fragile protein crystals and streamlining the process of protein structure analysis. We demonstrate the utility of our device using hen egg white lysozyme as a model system, followed by the crystallization and in situ, room temperature structural analysis of the hub domain of calcium-calmodulin dependent kinase II (CaMKIIβ).

Using Ion Substitution and Fluid Indicators to Monitor Macropinosome Dynamics in Live Cells.

All forms of endocytosis involve the incidental uptake of fluid (pinocytosis). Macropinocytosis is a specialized type of endocytosis that results in the bulk ingestion of extracellular fluid via large (>0.2μm) vacuoles called macropinosomes. The process is a means of immune surveillance, a point of entry for intracellular pathogens, and a source of nutrients for proliferating cancer cells. Macropinocytosis has also recently emerged as a tractable system that can be experimentally exploited to understand fluid handling in the endocytic pathway. In this chapter, we describe how stimulating macropinocytosis in the presence of extracellular fluids of a defined ionic composition can be combined with high-resolution microscopy to understand the role of ion transport in controlling membrane traffic.

Renal fluid and acid/base balance during refeeding in restrictive eating disorders.

Fluid shifts have been ascribed to central diabetes insipidus in patients with anorexia nervosa hospitalized for refeeding. Recent data, however, suggest that vasopressin production is not dysregulated in this population. Our objective was to describe the trajectory of fluid imbalances in relationship to kidney function, electrolyte disturbances, and acid/base balance during refeeding. A retrospective review of daily fluid balance and biochemical values was performed in 70 sequential unique patients admitted to University of California at Los Angeles Hospital Medical Stabilization Program for Eating Disorders from December 2018 to November 2020. Participants (2 males/68 females) were between 10 and 24 years of age and with a median body mass index of 16.1 (14.3, 18.1) kg/m2 . A severe negative fluid balance (>-900 ml/day) was observed in 80% of patients at some point during hospitalization. Serum sodium concentrations were normal on admission and remained stable during refeeding. Serum bicarbonate concentrations were 25 ± 1mEq/dl on admission and increased above the normal range in 31% of patients. Metabolic alkalosis was inversely associated with the development of a negative fluid balance. Estimated glomerular filtration rate was impaired in 54% of patients, improved with refeeding, and was not associated with the development of a severe negative fluid balance or metabolic alkalosis. Chronic energy deprivation alters the physiology of renal fluid and bicarbonate handling in ways that are independent of vasopressin and glomerular filtration. Further studies are warranted to understand the renal adaptations that occur during energy restriction and subsequent refeeding. Massive urinary fluid losses occur in patients with restrictive eating disorders hospitalized for refeeding. In addition, many patients have impaired renal bicarbonate excretion. These findings suggest that chronic energy deprivation impairs the kidney's ability to handle the shifts in fluid and acid/base balance that occur when appropriate oral nutrition is re-introduced.

Metal ions doping effect on the physicochemical, antimicrobial, and wound healing profiles of alginate-based composite

The alginate (Alg) matrix with immobilized hydroxyapatite (HAp) and zinc oxide (ZnO), cross-linked by chitosan (CS) and metal ions (Men+) Ca2+, Zn2+, and Cu2+ was created as a wound dressing. The effect of Men+ and their concentrations on water vapor transition, fluid handling, dehydration, drug release, and healing are shown. Me-containing samples have a lower sorption capacity, than a commercial Kaltostat, however, a much lower degree of their dehydration provides a longer wound wet. The Men+ presence lowers the environmental pH to slightly acidic values promoting healing. Ca2+, Zn2+, and Cu2+ in complexes with CS increase antimicrobial effect against E. coli and S. aureus, slow down the Anaesthesine release, making it compatible with Fickian diffusion in the Zn2+ and Cu2+ presence, and non-Fickian transport under Ca2+ influence. The material promotes the proliferation of the fibroblasts, an increase of collagen fibres, and new arterial and venous capillaries, indicating the intensity of the healing process.

Novel Biopolymer-Based Composite Wound Healing Wafers Containing Astragalus sarcocolla Gum

The aim of this research was the formulation development, optimisation and characterisation of wafers produced from various combinations of carrageenan  and tragacanth gum as potential carriers for wound healing extracts. Gels composed of one of the following three polymers: carrageenan (CAR), tragacanth gum (TG) and hydroxypropyl methylcellulose (HPMC) were prepared and freeze dried to obtain single polymer blank wafers. The blank wafers were examined for required lyophilisation behaviour and physical elegance of the resulting product. Based on these results, HPMC was eliminated and a combination of CAR:TG at seven different polymer ratios was chosen for further research. These CAR:TG wafers were characterised using scanning electron microscope (SEM), X-ray diffraction(XRD), texture analysis (hardness and mucoadhesion), Fourier transform infraredspectroscopy (FTIR), swelling tests and fluid handling properties. The formulations with the optimal properties were selected for loading with the extract and the drug-loaded wafers were subsequently further characterised as above.

Numerical and experimental investigations of uniform fluid distribution for droplet formation in parallelized microfluidics

Droplet microfluidics, which is the manipulation and handling of fluid in microscale channels, has excellent applications in material science, chemical synthesis, genetic analysis, drug discovery and delivery, organ on chips, and tissue engineering. Consequently, this field has attracted significant attention from both academic institutions and industries. However, one of the major constraints is increasing the droplet production rate from a single generator to thousands of generators in order to move from a laboratory scale to industrial standards. Although the scale-up method (in this case, parallelization) of droplet production using theoretical calculations has been extensively investigated, it has been discovered to be occasionally unreliable during experiments. The use of computational fluid dynamics (CFD) simulation, which has recently been applied to droplet microfluidics, has helped to determine the exact factors and conditions required for uniform droplet formation in flow-focusing devices. Thus far, there has been limited study on the simulation of distribution structures that effectively supply fluids to microfluidic devices in parallel orientation. In this study, CFD is used to provide detailed insights into the conditions required to achieve uniform fluid distribution in the delivery and/or distribution channel of microfluidic devices, and experimental analysis is used to further validate the findings.

Etiology- and region-specific characteristics of transependymal cerebrospinal fluid flow.

Transependymal flow (TEF) of CSF, often delineated as T2-weighted hyperintensity adjacent to the lateral ventricles on MRI, is a known imaging finding, usually in the setting of CSF flow disturbances. Specific radiological features of TEF and their relationships with clinical markers of hydrocephalus and underlying disease pathology are not known. Here, the authors describe the radiological features and clinical associations of TEF with implications for CSF circulation in the setting of intracranial pathology. After obtaining IRB review and approval, the authors reviewed the radiological records of all patients who underwent intracranial imaging with CT or MRI at St. Louis Children's Hospital, St. Louis, Missouri, between 2008 and 2019 to identify individuals with TEF. Then, under direct review of imaging, TEF pattern, degree, and location and underlying pathology and other radiological and clinical features pertaining to CSF circulation and CSF disturbances were noted. TEF of CSF was identified in 219 patients and was most prevalent in the setting of neoplasms (72%). In 69% of the overall cohort, TEF was seen adjacent to the anterior aspect of the frontal horns and the posterior aspect of the occipital horns of the lateral ventricles, and nearly half of these patients also had TEF dorsal to the third ventricle near the splenium of the corpus callosum. This pattern was independently associated with posterior fossa medulloblastoma when compared with pilocytic astrocytoma (OR 4.75, 95% CI 1.43-18.53, p = 0.0157). Patients with congenital or neonatal-onset hydrocephalus accounted for 13% of patients and were more likely to have TEF circumferentially around the ventricles without the fronto-occipital distribution. Patients who ultimately required permanent CSF diversion surgery were more likely to have the circumferential TEF pattern, a smaller degree of TEF, and a lack of papilledema at the time of CSF diversion surgery. CSF transmigration across the ependyma is usually restricted to specific periventricular regions and is etiology specific. Certain radiological TEF characteristics are associated with tumor pathology and may reflect impaired or preserved ependymal fluid handling and global CSF circulation. These findings have implications for TEF as a disease-specific marker and in understanding CSF handling within the brain.

Revisiting the relationship between (Pro)Renin receptor and the intrarenal RAS: focus on the soluble receptor.

The (pro)renin receptor (PRR), also termed as ATPase H+ transporting accessory protein 2 (ATP6AP2), was originally cloned as a specific receptor for prorenin and renin [together called (pro)renin]. Given the wide tissue distribution of PRR, PRR was further postulated to act as a regulator of tissue renin. However, assigning a physiological role of PRR within the renin-angiotensin system (RAS) has been challenging largely due to its pleotropic functions in regulation of embryogenesis, autophagy, and H+ transport. The current review will summarize recent advances in understanding the roles of sPPR within the intrarenal RAS as well as those outside this local system. Site-1 protease (S1P) is a predominant source of sPPR at least in the kidney. So far most of the known physiological functions of PRR including renal handling of electrolytes and fluid and blood pressure are mediated by sPRR. In particular, sPRR serves as a positive regulator of collecting duct renin to activate the intrarenal RAS during water deprivation or angiotensin-II (AngII) infusion. However, PRR/sPRR can act in renin-independent manner under other circumstances. S1P-derived sPRR has emerged as a key regulator of kidney function and blood pressure and its relationship with the intrarenal RAS depends on the physiological context.

How Should Clinical Wound Care and Management Translate to Effective Engineering Standard Testing Requirements from Foam Dressings? Mapping the Existing Gaps and Needs.

Significance: Wounds of all types remain one of the most important, expensive, and common medical problems, for example, up to approximately two-thirds of the work time of community nurses is spent on wound management. Many wounds are treated by means of dressings. The materials used in a dressing, their microarchitecture, and how they are composed and constructed form the basis for the laboratory and clinical performances of any advanced dressing. Recent Advances: The established structure/function principle in material science is reviewed and analyzed in this article in the context of wound dressings. This principle states that the microstructure determines the physical, mechanical, and fluid transport and handling properties, all of which are critically important for, and relevant to the, adequate performances of wound dressings. Critical Issues: According to the above principle, once the clinical requirements for wound care and management are defined for a given wound type and etiology, it should be theoretically possible to translate clinically relevant characteristics of dressings into physical test designs resulting specific metrics of materials, mechanical, and fluid transport and handling properties, all of which should be determined to meet the clinical objectives and be measurable through standardized bench testing. Future Directions: This multidisciplinary review article, written by an International Wound Dressing Technology Expert Panel, discusses the translation of clinical wound care and management into effective, basic engineering standard testing requirements from wound dressings with respect to material types, microarchitecture, and properties, to achieve the desirable performance in supporting healing and improving the quality of life of patients.

Experimental and numerical approach to predict slurry erosion in jet erosion test rig

Surface degradation due to slurry erosion is the common phenomenon encountered in fluid handling and material processing industries. Slurry erosion research initiated at the latter half of the twentieth century. Huge economic losses incurred through slurry erosion, to such an extent that components can't be repaired. Erosion is a complex process, because it operates with many factors and these factors contribute individually and in combined form, they affect severely. To evaluate materials' behavior under erosion environment, slurry erosion test rigs are developed. Numerous jet erosion test rigs are developed, yet standardization of the test method is unattainable due to its intricacy. Jet type slurry erosion test rigs are the preferable choice, as they offer flexibility with the test parameters and it could provide impact characteristics. Erodents' introduction is a tedious task, as particles have to be introduced into the flowing fluid. In the present article, a novel device named modified Venturi device is developed. Performance of the test rig is evaluated by varying the operating test parameters and by evaluating Cast Iron sample as the candidate material. From the results, it is noticed that developed test rig can be successfully employed to evaluate the erosion behavior. Erosion depends on the kinetic energy and the drag force on the particle. Numerical approach through CFD has been adopted and found that the experimental results are in good correlation with Finnie erosion model. SEM Micrographs reveal the material removal mechanism in the test rig.

An Integrated Pulsation-Free, Backflow-Free Micropump Using the Analog Waveform-Driven Braille Actuator.

The widespread adoption of long-term organs-on-a-chip culture necessitates both active perfusions that mimic physiological flow conditions and minimization of the complexity of microfluidic system and fluid handling. In particular, flow in microtissue such as microvascular is free of pulsation and backflow. The refreshable Braille actuator-based integrated microfluidic system can be employed with simple microchannels and setups. However, due to high pulsatile flow and backflow, ordinary Braille-driven micropumps generate non-physiological flow conditions. We have described a simple method for creating steady flow employing Braille actuators driven with a high-voltage analog waveform, called “constant flow waveform”, without incorporating complicated structures into the microchannel or actuator. We determined the constant flow waveform by measuring volume change of microchannel caused by actuated Braille pins using a conventional fluorescent dye and microscope. Using the constant flow waveform, we demonstrated that a Braille-driven pump reduced pulsating flow by 79% and backflow by 63% compared to conventional Braille-driven pump. Furthermore, we demonstrated that a parallel pair of three-stranded pin pumps effectively eliminated backflow by driving two pumps with the constant flow waveform half-cycle shifted to each other. Moreover, by raising the driving frequency, we could increase the average flow rate to ~2× higher than previously reported flow rate of a typical Braille-driven micropump.

Microfluidics and Macrofluidics in Space: ISS-Proven Fluidic Transport and Handling Concepts

Fluid transport and handling in extraterrestrial conditions, i.e. microgravity, require significantly different system engineering than here on Earth. On Earth, a notable part of fluid processing units inherently relies on buoyancy to transport and handle fluids. In space, however, buoyancy effects are negligible due to the strong diminishment of gravity, resulting in the domination of surface tension forces. Surface tension forces are also dominating micro-scale processes in gravity, making microfluidics a promising technology for fluidic transport and handling in microgravity. Recently, three different microfluidics-suitable fluid behavior phenomena have been studied on the ISS that might further facilitate the manipulation of fluids in space: capillary-driven flow, thermocapillary Marangoni forces, and electrolytic gas evolution-driven flow. Furthermore, attention is drawn for strategies to eliminate unwanted bubbles from liquid bodies in space, as they can damage sensitive equipment: Mesh-screen capillarity and open wedge channels have been identified as promising approaches. Finally, the relevance of fluid handling in space is illustrated with everyday activities during space missions, such as drinking, plant watering, and gathering biometric data.