Change In Contact Angle Research Articles

The effect of repetitive frying on physicochemical properties of refined, bleached and deodorized Malaysian tenera palm olein during deep-fat frying

Refined, bleached and deodorized tenera palm olein is widely used for domestic and commercial food frying. However, repeated heating and frying might lead to oil spoilage. This study focuses on the effect of deep-frying on physicochemical properties of repeatedly heated palm olein. Recycled palm olein was prepared by frying potato strips up to 5 cycles with potato-to-oil (g/ml) ratio of 3:20 prior to colour, density, viscosity, moisture content, contact angle, peroxide value and iodine value analyses. The fluctuation in the temperature of the oil was insignificant for every cycle (p > 0.05). The increase in red colour of the oil was significant (p < 0.05) after two cycles of frying from 3.6 to 5.0 Lovibond unit. After 5 frying cycles, there was no change in the density of RBDPO-2 and RBDPO-3. The viscosity of the oil after 5 frying cycles was higher as compared to after 5 heating cycles (67.7 ± 0.6 and 58.2 ± 0.9 cP respectively). Besides, the viscosity of RBDPO-3 was lower than RBDPO-2 only. The moisture content of the oil increased from 3.7 ± 0.1% to 30.4% (w/w) for RBDPO-2, whereas for RBDPO-3, the viscosity increased from 3.7 ± 0.1% to 30.4 ± 0.1% (w/w) due to the presence of the moisture from the potato. The change in the contact angle of the RBDPO-1 (control) was significant (p < 0.05) between the 1st cycle and the 5th cycle from 19.16 ± 0.45° to 12.03 ± 0.45° respectively. Besides, there was a significant change (p < 0.05) of contact angle for RBDPO-2 between the 1st cycle and the 5th cycle from 32.53 ± 0.5° to 18.06 ± 0.15° respectively. The peroxide value of the fresh oil was 2.8 ± 0.2 meq/kg and the value after the 1st cycle for all RBDPO(s) treatment increased, indicating that primary oxidation had occurred after the 1st cycle of heating and frying. A decreasing trend was observed from the 2nd until the 5th frying cycle because the instability of peroxide at a high temperature, causes rapid degradation and produced a dimer and volatile compound. Frying also decreased the unsaturated value of the oil as indicated by a decrease in the iodine value. Based on Pearson’s correlation test, there was a positive correlation between the colour, density and viscosity of the oil. The higher the peroxide value, the higher the density of the oil. There was also a positive correlation between the contact angle, moisture content and peroxide value of the oil. Whereas, a negative correlation was found between the iodine values, colour, density and viscosity of the oil. In conclusion, the potato repetitive deep-frying darkened the colour of the oil, increased its density, viscosity, contact angle, and peroxide value and decreased the degree of unsaturation of the oil as it shows a prominent sign of oxidative rancidity.

Apparent Contact Angle around the Periphery of a Liquid Drop on Roughened Surfaces

The wetting of roughened surfaces is complicated since not all of the surface of the irregular surface is wetted and thus, the three-phase contact line for the liquid drop is a complex, three-dimensional line that varies according to the dimensions of the roughness and its spatial heterogeneity. This can cause the contact line to not sit within a constant height horizontal plane especially when air is trapped underneath the liquid layer. Here, we explore the effect of roughness on the effective contact angle of a water droplet on a roughened hydrophobic surface. The results show that the apparent contact angle varies around the periphery of the droplet due to the roughness of the surface on first contact. Also, repeated wetting of the droplet on the surface reveals that the apparent contact angle changes due to residual liquid remaining on the roughened surface. The results also show that the Wenzel and Cassie-Baxter models tend to overestimate the apparent contact angle on the roughened surfaces.

Oxidation effect of copper on the downward-facing flow boiling CHF under atmospheric condition

In the present study, experiments of downward-facing flow boiling were conducted to investigate oxidation effects of copper under atmospheric conditions. The copper surface was polished and then put into a drying oven for a period of 1 h, 3 h and 6 h under 300°C. Compared with a bare surface, a deterioration in the heat transfer coefficient and an enhancement in critical heat flux (CHF) was found in the oxidized case for three mass flux conditions. With the mass flux increasing, the CHF enhancement ratio decreased. After oxidation, the contact angle decreased. Although many previous studies tried to explain the CHF enhancement by the change of contact angle, it was difficult to be applied in the downward-facing flow boiling. The enhancement of CHF was associated with nucleation site density (NSD) change caused by the surface morphology change during oxidation. Fewer bubbles generated on the copper surface after oxidation. The number of bubbles generated on the surface was calculated by a python code and it showed an inverse relationship with CHF, which was explained by a model. Under higher heat flux, the vapor cover area decreased, which was a result of the reduction in NSD after oxidation. Microscope images showed the decrease of the number of cavities on the surface, which was likely to be the reason for the decreasing of NSD.

Change in wetting characteristic of heated refrigerant in falling film evaporation

Abstract The wetting area plays a critical role in falling film evaporation. In the falling film evaporation process, the refrigerant is observed to shrink to a narrow rivulet when heated at a low temperature difference. In this study, a new model based on the stable rivulet and micro-layer evaporation theories was built to explain this phenomenon. A falling film evaporation experiment was conducted with R134a to examine the accuracy of the model. The calculation of the rivulet's width has good agreement but a little smaller than the experiments. Moreover, the theoretical analysis shows that the thermal-capillary effect will intensify the shrinkage of the rivulet, but the apparent contact angle change in the heated refrigerant is mainly caused by the evaporation of the micro-film. The decreased cross section of the rivulet will also attribute to the shrinkage. In conclusion, although the changed contact angle is small, the reduction of the wettability of refrigerant in falling film evaporation process cannot be neglected.

Laser-Induced Periodic Surface Structuring of Poly(trimethylene terephthalate) Films Containing Tungsten Disulfide Nanotubes.

We report the study of the formation of Laser Induced Periodic Surface Structures (LIPSS), with UV femtosecond laser pulses (λ = 265 nm), in free-standing films of both Poly(trimethylene terephthalate) (PTT) and the composite PTT/tungsten disulfide inorganic nanotubes (PTT-WS2). We characterized the range of fluences and number of pulses necessary to induce LIPSS formation and measured the topography of the samples by Atomic Force Microscopy, the change in surface energy and contact angle using the sessile drop technique, and the modification in both Young’s modulus and adhesion force values with Peak Force-Quantitative Nanomechanical Mapping. LIPSS appeared parallel to the laser polarization with a period close to its wavelength in a narrow fluence and number of pulses regime, with PTT-WS2 needing slightly larger fluence than raw PTT due to its higher crystallinity and heat diffusion. Little change was found in the total surface energy of the samples, but there was a radical increase in the negative polar component (γ−). Besides, we measured small variations in the samples Young’s modulus after LIPSS formation whereas adhesion is reduced by a factor of four. This reduction, as well as the increase in γ−, is a result of the modification of the surface chemistry, in particular a slight oxidation, during irradiation.

Biodegradation of Polystyrene by Pseudomonas sp. Isolated from the Gut of Superworms (Larvae of Zophobas atratus).

Recently, various attempts have been made to solve plastic waste problems, such as development of biodegradation without producing pollution. Polystyrene (PS) is the fifth most used plastic in many industries; therefore, degrading PS becomes a critical global issue. Here, we reported Pseudomonas aeruginosa strain DSM 50071, initially isolated from the gut of the superworms, Zophobas atratus, and the PS degradation by Pseudomonas sp. DSM 50071. We examined PS degradation using electronic microscopy and measured changes in atomic composition and contact angles with water droplets on the PS surface that represents a chemical change from hydrophobicity to hydrophilicity. We have further examined chemical structural changes using X-ray photoelectron spectroscopy, Fourier-transform-infrared spectroscopy, and nuclear magnetic resonance (NMR) to confirm the formation of carbonyl groups (C═O) in the oxidation pathway during PS biodegradation. In reverse transcription quantitative polymerase chain reaction analysis, the gene expression level of serine hydrolase (SH) in Pseudomonas sp. DSM 50071 was highly increased during PS degradation, and the enzyme-mediated biodegradation of PS was further confirmed by the SH inhibitor treatment test. Thus, the significance of these findings goes beyond the discovery of a novel function of Pseudomonas sp. DSM 50071 in the gut of superworms, highlighting a potential solution for PS biodegradation.

Influence of lead-manganese naphthenate on changes in the dynamic edge wetting angle upon spreading of styrene-acrylic dispersion

The effect of lead-manganese naphthenate on the change in the dynamic contact angle during spreading of a styrene-acrylic dispersion is studied. The dependences of the change in the dynamic contact angle in time are obtained for various concentrations of lead-manganese naphthenate in solution. As a result of the analysis of the experimental data, a concentration region was revealed in which the dynamic wetting angle varies in the widest range with the lowest speed compared to solutions of other concentrations. The results of the research will be used to optimize the composition of the polymer-mineral composite material and will make it possible to obtain a polymer matrix that most wetts the mineral fillers, and the resulting composite will have the greatest mobility and vitality.

Dynamic characteristics and reliability analysis of ball screw feed system on a lathe

For ball screw feed system on a lathe, the randomness of geometric parameters deriving from the inevitable manufacturing and assembly errors significantly affected the system dynamic characteristics and turning accuracy. In this study, a novel lumped dynamic model accounting for the analytical piecewise restoring force function involving the overall axial deformation is proposed. The equivalent mechanical model of bearing joints including the change of nominal contact angle is made a reasonable simplification to facilitate acquisition of the system analytical equation of motion. Additionally, the approximate analytical solution of the proposed equation is obtained by the modified Lindstedt–Poincaré method (MLP). The advanced first order second moment method (AFOSM) is employed to evaluate the reliability of dynamic response error. Furthermore, the numerical simulation aims to demonstrate the capabilities of the MLP and AFOSM method in the practical applications. Eventually, the effects of external excitation, sliding platform position, and nominal contact angles on the dynamic response are discussed and the reliability and sensitivity analysis in accordance with actual turning accuracy level is presented.

Wettability of Wood Surface Layer Examined From Chemical Change Perspective

The effect of artificial ageing on spruce (Picea abies), beech (Fagus sylvatica L.), birch (Betula pendula), and sessile oak (Quercus petraea) wood surfaces were investigated using qualitative (total phenolic and total soluble carbohydrate content) chemical examination methods. During ageing (∑240h), the influence of surface chemistry modifications was monitored by contact angle measurements of polar, dispersive (distilled water), and dispersive (diiodomethane) liquids. The results clearly show the relation between the ratio of main chemical components of the wood surface layer and surface wettability during artificial radiation. The identified surface chemistry modifications cause more significant change in the contact angle of polar and dispersive liquid, relative to the change of dispersive liquid contact angle. Chemical changes of the wood surface layer are due to the degradation of the main wood components (cellulose, hemicelluloses, and lignin) which can be properly monitored by total phenolic (TPC) and total soluble carbohydrate content (TSCC) measurements.

Highly biodegradable, ductile all-polylactide blends

All-PLA blends have been fabricated by an easily scalable and green melt-blending of linear-PLLA and 3-armed star-shaped PDLLA at different proportions (100:0, 95:5, 90:10, 80:20, and 50:50, w:w). The fabrication process, carried out in a hot-press, consisted of three steps: an initial heating of the thoroughly blended polymer mixtures at 170 °C for 5 min, a second heating at 170 °C for 5 min with a pressure of 200 Pa, and a final cooling at room temperature during 20 min keeping the same pressure. This methodology resulted in very homogenous amorphous samples, as revealed by XRD and DSC. The incorporation of star-PDLLA toughened the polylactide matrix by a clear ductilization, opening opportunities for the expanded use of the developed blends in different applications, due to their increased processability. DSC analysis revealed indeed that by increasing star-PDLLA content it is possible to gradually reduce the Tg, as well as the capability of crystallization of the linear-PLLA component. Such properties determine a plasticizing effect on the final blends. The increased content of the star component turned the films from transparent to translucent and decreases the thermal decomposition temperatures, which remain in any case very well above room temperature. The water vapor transmission rates varied with the star-PDLLA content between values characteristic for isolating to breathable films, thus allowing the use of these blends in different applications such as food packaging and biomedical devices. Finally, no important changes of water contact angle and water uptake were observed between the different blends. Despite the negligible effect of seawater on the biodegradation of commercial PLA, star-PDLLA-containing blends showed high biodegradation rates at short-times in marine environments, reinforcing the environmentally friendly character of polylactide.

Ultra-flexibility, robust waterproof and breathability of polyvinylidene fluoride membrane blended silver nitrate for electronic skin substrate

Flexibility, waterproof and breathability of substrates are the key issues restricting the application of electronic skin. Composite nanofibrous membranes (CNFMs) as substrates of electronic skin are prepared from polyvinylidene fluoride and silver nitrate blended solution by electrospinning technique. The microstructure and performances of the CNFMs are characterized by scanning electron microscopy, x-ray diffraction, capillary pore size analyzer, gravimetric method, water vapor permeability tester, optical contact angle tester, water permeability tester, intelligent electronic strength tester, hand-held electronic thickness meter and seveneasy conductivity meter. The results indicate that with the introduction of silver nitrate, the waterproof and breathability of CNFMs are balanced and optimized. The moisture permeability increases by 22%–69% from 2915.9 g · m−2 · 24 h−1 of pristine nanofibrous membrane (PNFM) to 3801.2–4151.5 g · m−2 · 24 h−1 of CNFMs and the hydraulic pressure decreases from 23.4 kPa to 21.6–16.5 kPa. However, the change of contact angle is irregular, which depends on the presence of like lotus-leaf-papillae morphology on fiber surface. The tensile strength of CNFMs decreases greatly and the elongation increases by 3–8 times from 7.7% of PNFM to 25.1%–63.2% of the CNFMs. The improvement of CNFMs flexibility is attributed to the hierarchical roughness of nanofiber surface, the unlock bonding between fibers and various combination forms of silver particles in CNFMs. Thus it was suitable to be applied as the substrate of electronic skin.

Electrowetting: A Consideration in Electroadhesion.

With the commercialization of haptic devices, understanding behavior under various environmental conditions is crucial for product optimization and cost reduction. Specifically, for surface haptic devices, the dependence of the friction force and the electroadhesion effect on the environmental relative humidity and the finger hydration level can directly impact their design and performance. This article presents the influence of relative humidity on the finger-surface friction force and the electroadhesion performance. Mechanisms including changes to Young's modulus of skin, contact angle change and capillary force were analyzed separately with experimental and numerical methods. Through comparison of the calculated capillary force in this paper and the electroadhesion force calculated in published papers, it was found that electrowetting at high voltage could contribute up to 60% of the total friction force increase in electroadhesion. Therefore, in future design of surface haptic devices, the effect of electrowetting should be considered carefully.

Effect of the primer on barcode quality in ink-jet printing

It has been proposed to modify the surface of offset and coated paper with a special coating (primer) that ensures the high quality of ink-jet printing, specifically barcodes. The application of digital ink-jet printing using aqueous-based inks makes it difficult to achieve the required print quality on conventional paper. Ink-jet printing is widely used in the production of customized packaging and labeling products. Given that this type of products contains the printed barcode, it is necessary to ensure its functionality (readability) after printing.The primer ensures a controlled process of ink absorption at ink-jet printing, thereby improving the print quality. To this end, a composition of the primer was used on the basis of a water solution of the interpolymeric complex of polyvinyl alcohol (PVOH) and polyvinylpyrrolidone (PVP).The influence of the primer that contains different amounts of the interpolymeric complex on a change in the water contact angle of imprinted paper has been investigated.Prints on paper with and without the primer were obtained using an ink-jet printing method; quality of the line and barcode print was assessed. Such quality indicators for the line were defined as a line width on the imprint, a line blurriness at the line-paper interface, a line raggedness, and the optical density. In addition, the primer's effect on the barcode print quality at ink-jet printing was investigated.The study results make it possible to ensure the high quality of barcode printing on conventional print papers by using an ink-jet printing method. Applying the primer improves the line and barcode print quality. The barcode quality grade increases from the lowest (unacceptable) score of 0 (F) on paper without a primer to a score of 2 (C) on paper with the primer, which warrants that it is readable on packaging by a scanner.

Wetting of glass surface using natural surfactants

Background: Surfactant adsorption at the interfaces (solid–liquid, liquid–air, or liquid–liquid) is receiving considerable attention from a long time due to its wide range of practical applications. Objective: Specifically wettability of solid surface by liquids is mainly measured by contact angle and has many practical importances where solid–liquid systems are used. Adsorption of surfactants plays an important role in the wetting process. The wetting behaviours of three plant-based natural surfactants (Reetha, Shikakai, and Acacia) on the glass surface are compared with one widely used nonionic synthetic surfactant (Triton X-100) and reported in this study. Methods: The dynamic contact angle study of three different types of plant surfactants (Reetha, Shikakai and Acacia) and one synthetic surfactant (Triton X 100) on the glass surface has been carried out. The effect of two different types of alcohols such as Methanol and amyl alcohol on wettability of shikakai, as it shows little higher value of contact angle on glass surface has been measured. Results: The contact angle measurements show that there is an increase in contact angle from 47° (pure water) to 67.72°, 65.57°, 68.84°, and 68.79° for Reetha, Acacia, Shikakai, and Triton X-100 respectively with the increase in surfactant concentration and remain constant at CMC. The change in contact angle of Shikakai-Amyl alcohol mixtures are slightly different than that of methanol-Shikakai mixture, mostly there is a gradual increase in contact angle with the increasing in alcohol concentration. Conclusion: There is no linear relationship between cos θ and inverse of surface tension. There was a linear increase in surface free energy results with increase in concentration as more surfactant molecules were adsorbing at the interface enhancing an increase in contact angle.

The Interaction Force between Scheelite and Scheelite/Fluorite/Calcite Measured Using Atomic Force Microscopy

The mechanism of the formation of the hydrophobic agglomerate in fine scheelite flotation was studied using zeta potential measurement, contact angle measurement, optical microscope measurement, and atomic force microscopy (AFM) colloid probe technology. Zeta potential measurement results confirmed the adsorption of sodium oleate on scheelite, fluorite, and calcite surface and surface potential difference at different pH values of ultrapure water. Contact angle measurement results confirmed the surface of nature scheelite, fluorite, and calcite was hydrophilic, and the surface after thread by sodium oleate solution was hydrophobic. The optical microscope measurement results confirmed the agglomerates could really form in ultrapure water of pH 8 or 10 and in 1 mM sodium oleate solution of pH 10. The agglomerations were empty and not tight in ultrapure water. On the contrary, the hydrophobic agglomerations were larger and denser after treated with sodium oleate solution than that of in ultrapure water. According to the AFM experiment results, the interaction forces on hydrophilic scheelite-scheelite and scheelite-fluorite were repulsive at pH 5.6 and attractive at pH 8 or 10. However, the interaction forces on hydrophilic scheelite-calcite were attractive at pH 5.6, 8 or 10. The interaction forces on hydrophobic scheelite-scheelite, scheelite-fluorite, and scheelite-calcite were attractive strongly due to the existence of hydrophobic force. The measurement results of the interaction forces were in good agreement with the changes of zeta potential and contact angle at different conditions. The combined results could be beneficial to understand the interaction force in fine scheelite flotation.

Application of dielectric barrier discharge plasma to hydrophobically modification of gum arabic with enhanced surface properties

The aim of the present study was to evaluate the effect of cold atmospheric-pressure plasma (CAP) on the structural aspects and some physicochemical properties of gum arabic (GA), with emphasis on its surface properties. GA was treated at dielectric barrier discharge (DBD) plasma with ambient air for different times (20, 40, and 60 min). The optical emission spectroscopy (OES) was utilized to scope present active species in the plasma. Upon treatment, the structural, thermal and morphological variations, as well as changes in water contact angle, surface and interfacial tension, molecular weight, solubility, moisture content and color of the treated gums, were studied. Compared with GA, overall significant changes in the spectra of all treated gums were recognized, particularly in the range of 1200–1750 cm−1. Elemental analysis of surface demonstrated that both oxygen and nitrogen content of treated gum increased time-dependently. Plasma had no pronounced effect on the amorphous nature of GA. Water contact angle data showed that plasma treatment was surprisingly capable of transforming GA hydrophilic nature into hydrophobic. The surface roughness of the treated gums powder time-dependently increased. The molecular weight, solubility, and moisture content of treated gum nonlinearly decreased with increasing treatment duration. The surface and interfacial tension significantly decreased after CAP treatment. The thermal properties and color of the treated gums changed after CAP treatment. In total, this study confirmed that the CAP treatment was an efficient approach to improve surface properties of gum arabic.

Predicting inkjet dot spreading and print through from liquid penetration- and picoliter contact angle measurement

AbstractIn this study we have evaluated the suitability of laboratory testing methods to predict inkjet printing results. We have developed and used testing liquids that are spanning the operational window of industrial High Speed Inkjet (HSI) printers while still covering the maximum possible range of viscosity and surface tension. First we correlated liquid penetration measured with ultrasound (ULP) and direct absorption (ASA) to print through from HSI prints. The best correlation (R2≈0.7{R^{2}}\approx 0.7) was found for the sized paper. For papers with increasing liquid penetration speed we found a decreasing ability of both testing methods to predict print through, for the strong absorbing paper the correlation drops toR2≈0.2{R^{2}}\approx 0.2. Second we correlated contact angle and drop diameter to the dot area from HSI prints. Contact angle turned out to be a better predictor for printed dot area than drop diameter. Evaluating the change in contact angle over time we found the highest correlation to the dot area in the print when measuring the contact angle as soon as possible, in our case 1 ms after deposition of the drop on the paper. We also compared contact angle with microliter drops to picoliter drops, which are in the size scale of the actual inkjet droplet. To our great surprise correlations for microliter drops were equal or better than for picoliter drops, particularly for highly absorbing papers. Thus in order to predict dot spreading on paper our results suggest to measure the contact angle with microliter drops. Overall we found that, using laboratory testing methods, print through and dot spreading for HSI printing can be quite well predicted for slow absorbing papers but not very well for fast absorbing papers.

Coating Topologically Complex Electrospun Fibers with Nanothin Silk Fibroin Enhances Neurite Outgrowth in Vitro.

Electrospun poly-l-lactic acid (PLLA) fibers are commonly used for tissue engineering applications because of their uniform morphology, and their efficacy can be further enhanced via surface modification. In this study, we aimed to increase neurite outgrowth along electrospun fibers by coating with silk fibroin (SF), a bioinert protein derived from Bombyx mori cocoon threads, shown to be neurocompatible. Aligned PLLA fibers were electrospun with smooth, pitted, and divoted surface nanotopographies and coated with SF by immersion in coating solution for either 12 or 24 h. Specifically, thin-film coatings of SF were generated by leveraging the controlled self-assembly of SF in aqueous conditions that promote β-sheet assembly. For both 12- and 24-h coatings, Congo Red staining for β-sheet structures confirmed the presence of SF coatings on PLLA fibers. Confocal imaging of fluorescein-labeled SF further demonstrated a homogeneous coating formation on PLLA fibers. No change in the water contact angle of the surfaces was observed after coating; however, an increase in the isoelectric point (pI) to values comparable with the theoretical pI of SF was seen. Notably, there was a significant trend of increased dorsal root ganglia (DRG) adhesion on scaffolds coated with SF, as well as greater neurite outgrowth on pitted and divoted fibers that had been coated with SF. Ultimately, this work demonstrated that thin-film SF coatings formed by self-assembly uniformly coat electrospun fibers, providing a new strategy to increase the neuroregenerative capacity of electrospun scaffolds. To our knowledge, this is the first instance of biomedical modification of topologically complex substrates using noncovalent methods.

Researches on hydrodynamics of liquid film flow on inclined plate using diffuse-interface method

The liquid film flow can consistently remove heat to reduce the pressure and temperature in the containment when a severe accident occurs in reactors. However, due to the various variable factors of the environment, such as angle of wall inclination and physical properties of liquids, the liquid film flow is complex in practice. In order to investigate the influences of inclined angle of plate, contact angle, surface tension and density on the hydrodynamics of liquid film, numerical simulation of liquid film flow on the inclined plate are studied by using the diffuse-interface method. Good agreements of the maximum liquid film thickness and the wave velocity are observed between experiment and simulation, proving that diffuse-interface method can be available to simulate the hydraulic characteristics of the liquid film flow. And the analysis of the influence of the above factors on liquid film flows show that the solitary wave phenomenon can be observed in the simulation; the wettability of liquid film flow becomes worse when the inclined angle and the contact angle increase; the change of contact angle is related to the surface tension; the wettability of the liquid film can be improved by increasing density of the liquid for the condition that the wettability is not good.

Liquid Lens with Large Focal Length Tunability Fabricated in a Polyvinyl Chloride/Dibutyl Phthalate Gel Tube

Usually, an adaptive liquid lens only has a positive focal length, which severely limits its application in imaging and other fields. Therefore, a liquid lens consisting of polyvinyl chloride/dibutyl phthalate (PVC/DBP) gel, glycerol solution, and a glass substrate is proposed to extend the dynamic focal length range. A spherical tube is formed by the PVC/DBP gel under the effect of hydrostatic and surface tensions, which is used to restrict the glycerol solution. The PVC/DBP gel does not deform under the effect of an electric field, so the tangent line at the three-phase junction changes with the change of contact angle, which leads to an enlargement of the dynamic focal length range. At different voltage values, the proposed lens can be configured to work in three different schemes, namely, converging light, nondeflecting light, and diverging light. Here, the proposed lens has high imaging quality; the resolution is better than 114 lp/mm. A lens with a reconfigurable focal length holds great promise in diverse applications such as fluorescence detection, beam shaping, and adaptive optics.