Coalescence-induced Droplet Jumping Research Articles

Nanoscale particle-droplet coalescence-induced jumping on superhydrophobic surfaces: Insights from molecular dynamics simulations

The removal of solid particles from superhydrophobic surfaces via coalescence-induced droplet jumping has gained increasing attention. However, the underlying mechanisms, especially the nanoscale dynamics of particle-droplet coalescence, remain largely underexplored. In our research, we employ molecular dynamics simulations to investigate the influences of the radius, wettability, and arrangement of solid particles on the particle-droplet jumping velocity and energy conversion efficiency. We observe notable rotational motions during the jumping events. Our findings reveal that the arc length of the wetted area on spherical particles and the spreading time of droplets exhibit a power-law relationship. As the particle-to-droplet radius ratio increases, the jumping velocity and energy conversion efficiency initially increase but subsequently decrease. Moreover, enhanced particle wettability leads to an increase in jumping velocity while a slight decrease in translational energy conversion efficiency. The velocities of coalescence-induced particle-droplet jumping at the nanoscale are consistent with predictions from the momentum model. Significantly, our results show that the rotationally symmetric multi-particle arrangements can effectively enhance the jumping velocity and energy conversion efficiency, thus improving particle removal efficiency. Our study not only deepens the understanding of coalescence-induced particle-droplet jumping behaviors, but also provides a foundation for developing more effective particle removal strategies on superhydrophobic surfaces.

Enhancement and Predictable Guidance of Coalescence-Induced Droplet Jumping on V-Shaped Superhydrophobic Surfaces with a Ridge.

Coalescence-induced droplet jumping has attracted significant attention in recent years. However, achieving a high jumping velocity while predictably regulating the jumping direction of the merged droplets by simple superhydrophobic structures remains a challenge. In this work, a novel V-shaped superhydrophobic surface with a ridge is conceived for enhanced and predictably guided coalescence-induced droplet jumping. By conducting experiments and lattice Boltzmann simulations, it is found that the presence of a ridge in the V-shaped superhydrophobic surface can modify the fluid dynamics during the droplet coalescence process, resulting in a much higher droplet jumping velocity than that achieved by the V-shaped superhydrophobic surface without a ridge. The enhancement of the droplet jumping velocity is mainly attributed to the combined effect of the earlier and more sufficient impingement between the liquid bridge and the ridge, as well as the accelerated droplet contraction by redirecting the internal liquid flow toward the jumping direction. A high normalized jumping velocity of is achieved by the newly designed surface, with a 930% increase in the energy conversion efficiency in comparison with that on a flat surface. Moreover, adjusting the opening direction of the V-groove at different groove angles is found to be an effective method to regulate the droplet jumping direction and expand the range of the jumping angle. Particularly, the droplet jumping angle can be well predicted based on the rotational angle (ω) and the groove angle (α), i.e., θj,p ≈ 90° - 0.5α - ω.

Fabrication of non-wetting surface on zinc substrate with coalescence-induced droplet jumping behavior for atmospheric corrosion protection

In this study, a superhydrophobic surface was constructed on the zinc substrate through a two-step process. The research first examined the correlations between the microstructure and coalescence-induced droplet jumping behavior (CIDJB). Then a droplet jumping phase map was created by considering energy principles. Finally, the performance and mechanism CIDJB in enhancing anticondensation effectiveness and salt spray experiments against atmospheric corrosion were revealed. This study provides insights into designing superhydrophobic surfaces with CIDJB for atmospheric corrosion protection. Further verification of the impact mechanism of environmental factors and stability and durability of CIDJB in practical applications will be investigated.

Effect of initial droplet position on coalescence-induced jumping on superhydrophobic surfaces with micropillar arrays

Coalescence-induced droplet jumping holds great potential for applications such as water harvesting, self-cleaning, and the thermal management of electronic devices. This study investigates the impact of the droplet's initial position on coalescence-induced jumping on superhydrophobic surfaces with micropillar arrays. Numerical simulations are conducted to examine the differences in droplet jumping at various initial positions with uniform and nonuniform micropillar distributions, and the effects of the droplet's initial position on its velocity and pressure distribution are analyzed. The findings indicate that altering the initial position produces an asymmetric distribution of the high-pressure region at the droplet's base and the pressure at the solid–liquid contact surface during the contraction of the liquid bridge. This asymmetry allows the droplet to jump away from the surface with both vertical and horizontal components of velocity, and to be transported in the horizontal direction. Furthermore, numerical simulations with various initial droplet positions and radii demonstrate that the direction of the horizontal jumping velocity is influenced by both the offset distance and the direction of the initial droplet position, and that the impact of the initial position decreases as the relative size of the droplet with respect to the micropillars increases. The droplet jumping velocity, direction, and horizontal transport distance can be controlled by adjusting the initial droplet position and size. This work reveals the mechanism of coalescence-induced droplet jumping on superhydrophobic surfaces with micropillar arrays and provides an important reference for practical applications.

Enhanced coalescence-induced droplet jumping on superhydrophobic surfaces with stepped structures

The coalescence-induced droplet jumping is a self-propelled water removal phenomenon on superhydrophobic surfaces, which has attracted considerable attention due to its potential in a wide range of applications such as self-cleaning and anti-icing/frosting. Improving the energy conversion efficiency, from the excessive surface energy to the kinetic energy, is pivotal to facilitate droplet jumping. In this study, we numerically investigated the dynamics of droplet coalescence on superhydrophobic surfaces with macro-stepped structures, with particular interest in understanding the role of the stepped structure on the droplet jumping process. Three-dimensional simulations were performed by using the lattice Boltzmann method, with the pseudopotential multiphase model and the multiple-relaxation-time collision operator being adopted to achieve high liquid–gas density/viscosity ratios. A wide range of nondimensional height difference of the stepped structure (0–1.5) and droplet radius ratio (0.5–2) was covered. Results show that adding macro-stepped structures can significantly enhance the droplet-wall interaction, thus yielding increased droplet velocity. The enhancement of droplet jumping is more remarkable for droplets of similar sizes, and the dimensionless height difference of the stepped structure is required to exceed a threshold of approximately 0.5. Among the present simulations, the maximum dimensionless droplet jumping velocity reaches 0.66, corresponding to an energy conversion efficiency of 35%. The present findings are helpful for the development of novel superhydrophobic surfaces that pursue efficient droplet removal.

Single Condensation Droplet Self-Ejection from Divergent Structures with Uniform Wettability.

Coalescence-induced condensation droplet jumping has been extensively studied for anti-icing, condensation heat transfer, water harvesting, and self-cleaning. Another phenomenon that is gaining attention for potential enhancements is the self-ejection of individual droplets. However, the mechanism underlying this process remains elusive due to cases in which the abrupt detachment of an interface establishes an initial Laplace pressure difference. In this study, we investigate the self-ejection of individual droplets from uniformly hydrophobic microstructures with divergent geometries. We design, fabricate, and test arrays of truncated, nanostructured, and hydrophobic microcones arranged in a square pattern. High-speed microscopy reveals the dynamics of a single condensation droplet between four cones: after cycles of growth and stopped self-propulsion, the suspended droplet self-ejects without abrupt detachments. Through analytical modeling of the droplet in a conical pore as an approximation, we describe the slow isopressure growth phases and the rapid transients driven by surface energy release once a dynamic configuration is reached. Microcones with uniform wettability, in addition to being easier to fabricate, have the potential to enable the self-ejection of all nucleated droplets with a designed size, promising significant improvements in the aforementioned applications and others.

Coalescence-Induced Droplet Jumping on Superhydrophobic Surfaces with Annular Wedge-Shaped Micropillar Arrays.

The coalescence-induced droplet jumping on superhydrophobic surfaces has extensive application potential in water harvesting, thermal management of electronic devices, and microfluidics. The rational design of the surface structure can influence the interaction between the droplet and the surface, thereby controlling the velocity and direction of the droplet's jumping. In this study, we fabricate the superhydrophobic surface with annular wedge-shaped micropillar arrays, examine the dynamic behavior of condensate droplets on the surface, and measure the temporal and spatial variations of droplet density, average radius, and surface coverage with wedge-shaped micropillars of varying sizes. In addition, the energy analysis of the coalescence-induced droplet jumping reveals that the two primary factors influencing the jumping are the relative size and position of the droplets and micropillars. Further numerical simulations find that the wedge-shaped micropillars cause an asymmetric distribution of pressure within the droplet and at the solid-liquid contact surface, which generates an unbalanced force driving the droplet in the gradient direction of the wedge-shaped micropillar, causing the droplet to jump off the surface with both vertical and gradient-direction velocities. The capacity of the wedge-shaped micropillar surface to transport droplets in the gradient direction increases and then decreases as the relative size of the droplets and micropillars increases. The relative position of the droplet center-of-mass line perpendicular to the bottom edge of the wedge micropillars' trapezoidal shape is more favorable for droplet transport. This work reveals the influence mechanism of surface structure on the velocity and direction of droplet jumping, and the results can guide the microstructure design of superhydrophobic surfaces, which has significant implications for the application of droplet jumping.

Coalescence-Induced Droplet Jumping for Electro-Thermal Sensing.

Jumping droplet condensation, whereby microdroplets (ca. 1-100 μm) coalescing on suitably designed superhydrophobic surfaces jump away from the surface, has recently been shown to have a 10× heat transfer enhancement compared to filmwise condensing surfaces. However, accurate measurements of the condensation heat flux remain a challenge due to the need for low supersaturations (<1.1) to avoid flooding. The low corresponding heat fluxes (<5 W/cm2) can result in temperature noise that exceeds the resolution of the measurement devices. Furthermore, difficulties in electro-thermal measurements such as droplet and surface electrostatic charge arise in applications where direct access to the condensing surface, such as in isolated chambers and small integrated devices, is not possible. Here, we present an optical technique that can determine the experimental electro-thermal parameters of the jumping droplet condensation process with high fidelity through the analysis of jumping droplet trajectories. To measure the heat flux, we observed the experimental trajectories of condensate droplets on superhydrophobic nanostructures and simultaneously matched them in space and time with simulated trajectories using the droplet dynamic equations of motion. Two independent approaches yielded mean heat fluxes of approximately 0.13 W/cm2 with standard deviations ranging from 0.047 to 0.095 W/cm2, a 79% reduction in error when compared with classical energy balance-based heat flux measurements. In addition, we analyzed the trajectories of electrostatically interacting droplets during flight and fitted the simulated and experimental results to achieve spatial and temporal agreement. The effect of image charges on a jumping droplet as it approaches the surface was analyzed, and the observed acceleration has been numerically quantified. Our work presents a sensing methodology of electro-thermal parameters governing jumping droplet condensation.

Effect of Microstructure on Coalescence-Induced Droplet Jumping Behavior of a Superhydrophobic Surface and Its Application for Marine Atmospheric Corrosion Protection

Coalescence-induced droplet jumping behavior (CIDJB) refers to the spontaneous jumping of droplets on a specific superhydrophobic surface (SS) without any external energy, which offers a new approach to the field of marine atmospheric corrosion protection by isolating corrosive media. In this study, a flower-like micro–nanocomposite structure SS (F-SS) and a sheet-like nanostructure SS (S-SS) were prepared on copper sheets by ammonia immersion and chemical vapor deposition. Firstly, we observed the microstructure characteristics of the samples and secondly analyzed its chemical composition and wettability. Moreover, the CIDJB was studied by simulated condensation experiments, and the influence of the microstructure on CIDJB was revealed. Meanwhile, the atmospheric corrosion resistance of samples was analyzed by electrochemical impedance spectroscopy (EIS) measurements, and the protection mechanism of SS through CIDJB was proposed. The results showed that the S-SS had a smaller solid–liquid contact area and lower interfacial adhesion, which is more conducive to CIDJB. Since a larger solid–liquid contact area requires greater interface adhesion energy for the droplets to overcome, droplet jumping behavior was not observed on the F-SS. Compared with the F-SS, the S-SS exhibited outstanding corrosion resistance due to the wettability transition of droplets by CIDJB, which facilitated the restoration of the air film to insulate the corrosive medium. The present study provides a reference for a marine atmospheric corrosion resistance technique through CIDJB on an SS.

Coalescence-induced droplet jumping on superhydrophobic surfaces with non-uniformly distributed micropillars

The phenomenon of droplet jumping induced by coalescence holds significant potential for application in diverse areas such as water collection, self-cleaning, and thermal management of electronic devices. In comparison to a flat surface, a superhydrophobic surface with structure can affect the interaction between the droplet and the surface, thereby affecting parameters such as the droplet jumping velocity. In this study, numerical simulation was used to examine the similarities and differences of coalescence-induced droplet jumping on superhydrophobic surfaces with uniform and non-uniform micropillars, as well as the effect of micropillar non-uniformity on droplet jumping. The results indicated that the non-uniform distribution of micropillars could lead to asymmetries in the shrinkage of the liquid bridge, the morphology of the droplet when it jumps off the surface, and the distribution of the high-pressure region at the bottom of the droplet. Additionally, it decreased the droplet’s vertical velocity while substantially increasing the horizontal velocity. When the droplet radius was constant, decreasing the micropillar width or increasing the micropillar spacing on the sparse side was advantageous for the droplet jumping on a superhydrophobic surface with non-uniform micropillars. By defining the solid fraction on the micropillar surface with non-uniform distribution, the coupling effect of the width and spacing of the micropillars on the droplet jumping was thoroughly analyzed, and the optimal solid fraction for the best directional transport effect of droplets was determined. This study revealed the mechanism underlying the effect of surface micropillar structure on coalescence-induced droplet jumping, and the findings could guide the design of superhydrophobic surface microstructures, which was of great significance for the advancement of droplet jumping applications.

Numerical study of the coalescence-induced droplet jumping with macrotexture based on single-phase model

The low energy conversion efficiency in coalescence-induced droplet jumping limits its potential for various applications, such as self-cleaning, anti-icing, and energy harvesting. Fortunately, it has been proven that this efficiency can be significantly increased through a sophisticated macrotexture design. In this study, we propose a single-phase model with a moving mesh to simulate the self-jumping process under a ridge. The effect of the ridge is realized by adopting a pointwise constraint on several surface nodes. This effective model is validated by experimental results of droplet velocity. In comparison with volume-of-fluid, a single-phase flow method enhances computational efficiency by at least 33.3%. The kinematics and dynamics of the self-jumping process have been investigated with respect to the influences of ridge height and Ohnesorge number. With the help of the radial distributions of velocity and internal pressure, the self-propelled process can be divided into coalescence-induced and lobe-induced stages. The high ridge brings more symmetry-breaking, accelerating the droplet in the coalescence-induced stage. In the lobe-induced stage, the slingshot effect is weakened under high Ohnesorge number due to the prolate shape caused by viscous dissipation. Moreover, the study's findings demonstrate promising application prospects for other ridge shapes, thereby expanding the potential practical applications of this research.

Study on the Coalescence-Induced Jumping of Droplets with Different Radii on Superhydrophobic Surface

The phenomenon of droplet coalescence and jumping has received increasing attention due to its potential applications in the fields of condensation heat transfer and surface self-cleaning. Basic research on the process and mechanism of coalescence-induced droplet jumping has been carried out, and some universal laws have been established. However, it is found that the focus of these studies is based on two identical droplets, and the coalescence-induced jumping with different radii is rarely investigated, which is commonly encountered in nature. Therefore, it is essential to proceed with the research of coalescence and jumping of droplets with unequal radii. In this paper, molecular dynamics (MD) simulations are performed to reveal the effects of radius ratio and radius of small droplets on jumping velocity. The results show that as the increasing of radius ratio with an unchanged small droplet radius of 8.1 nm, the jumping velocity increases then decreases, which indicates there is an optimal radius ratio to maximize the jumping velocity. Additionally, it is found that if the small droplet radius is changed, the critical radius ratio for characterizing whether the coalesced droplet jumping increases with increasing the small droplet radius. Furthermore, according to energy conservation, the conversion efficiency of energy is discussed. The results show that when the radius ratio is greater than 1.3 with three different small droplet radii, the energy conversion efficiency rapidly decreases to below 1.0%; and the critical radius ratios are consistent with the result obtained from the velocity analysis. This work broadens the understanding of the more general phenomenon of coalescence-induced droplet jumping and can better guide industrial applications.

When coalescing droplets jump: A unified energy conversion model incorporating droplet size and surface adhesion

Jumping-droplet condensation pushes the boundary of condensation heat transfer by enabling microdroplet shedding via coalescence-induced droplet jumping. The latter is empowered by surface-to-kinetic energy conversion. Regardless of extensive studies of droplet jumping on ideally non-wetting surfaces, a quantitative description of droplet jumping from realistic surfaces remains a challenge due to limited insight into the complex energy conversion process that is strongly coupled with droplet–droplet and droplet–substrate interactions. Here, we use a three-dimensional (3D) pseudopotential multiphase multiple-relaxation-time lattice Boltzmann method (MRT-LBM) to simulate binary-droplet coalescence with various droplet sizes and surface wettability. Then, we developed a comprehensive and unified energy conversion model, derived by rigorously analyzing the dynamic droplet–surface interaction and quantifying the roles of droplet size scale, droplet size mismatch, and surface wettability. Our simulations capture coalescence and jumping dynamics of arbitrary-sized droplets on surfaces having various wettability and reveal the effect of droplet size and surface wettability. Validated by experiments, the energy model is then used to define the jumping/non-jumping boundaries for coalescing droplets on nanostructured surfaces. Our work demonstrates the key physics and a universal criterion governing self-propelled droplet shedding, key to the design of surfaces for enhanced condensation heat transfer, anti-frosting/icing, self-cleaning, and water/energy harvesting.

Optimum substrate stiffness in coalescence-induced droplet jumping.

When droplets are brought into contact and coalesced on a superhydrophobic surface, the kinetic energy converted from the surface energy enables the merged droplet to jump. Current studies mainly focus on the microstructure of surfaces and the properties of droplets that influence the jumping dynamics. Here, by means of molecular dynamics, we investigate the coalescence-induced jumping of nanodroplets on soft substrates. The optimum stiffness of the substrate is suggested and the mechanism involved is demonstrated through the analysis of the interactions between the droplets and the substrates. The momentum of the droplet is evaluated by integrating the forces from the substrate. The optimum stiffness for jumping velocity is provided by the competition between the impact and the adhesion from the substrate during the process, which are both closely related to the stiffness. The results may inspire fundamental research and applications in a broad scope.

How macrostructures enhance droplet coalescence jumping: A mechanism study

Macrostructures exhibit excellent performance in coalescence-induced droplet jumping enhancement. Previous velocity prediction models were mainly established for flat plain surface, which usually set up the balance relationship between excess surface energy, kinetic energy and dissipation. But these models are no longer appropriate in macrostructure cases due to great variation of oscillational kinetic energy and gravitational potential energy caused by textures. In this work, coalescence-induced droplet jumping on macrostructures was investigated numerically on flat, sidewall, string, ridge and egg shape substrates. An energy conversion model based on energy efficiency rather than energy balance was established for departure velocity by proposing three sub-efficiencies to evaluate jumping enhancement. In this model, oscillational kinetic energy was distinguished from dissipation, gravitational potential energy induced by macrostructures were considered, and the real droplet morphology were used to calculate surface energy. By dividing the whole droplet jumping process into merge and contact stage, the influence of macrostructures on duration of each stage was closely connected to the macrostructure effects on dissipation and kinetic energy conversion. Pressure and velocity distributions near the macrostructure were also discussed to further explore the mechanism for droplet jumping enhancement. Further, the significant increase of initial surface energy for egg case points out a possible new approach to enhance jumping velocity. This model helps us understand the determinants of jumping enhancement with macrostructures and it also applies to flat plain.

Numerical Investigation on Coalescence-Induced Jumping of Centripetal Moving Droplets.

Coalescence-induced droplet jumping could promote self-removal of droplets, which has broad potential in related fields such as heat-transfer enhancement, self-cleaning, energy harvesting, electricity generation, radiative cooling, and antifrosting/icing. In practical applications, droplets often have initial velocity under external forces. In this work, the coalescence-induced jumping of centripetal moving droplets on a superhydrophobic plane is experimentally observed using a high-speed photography platform, and the effects of the initial velocity of the moving droplet on jumping velocity, energy conversion, and droplet morphology are numerically investigated. Results show that the jumping velocity decreases and then increases as the We number of the moving droplet increases. The main source of the total kinetic energy of the coalesced droplet switches from the released surface energy to the initial kinetic energy of the moving droplet with the increasing We number, but the proportion of the jumping kinetic energy to the total kinetic energy decreases. Besides, the initial velocity of the moving droplet intensifies the droplet deformation and accelerates the process of coalescence-induced jumping. Through theoretical analysis, it is found that the jumping velocity is affected by two mechanisms: the deformation intensification and the liquid bridge impact enhancement.

Particulate-Droplet Coalescence and Self-Transport on Superhydrophobic Surfaces.

Particulate transport from surfaces governs a variety of phenomena including fungal spore dispersal, bioaerosol transmission, and self-cleaning. Here, we report a previously unidentified mechanism governing passive particulate removal from superhydrophobic surfaces, where a particle coalescing with a water droplet (∼10 to ∼100 μm) spontaneously launches. Compared to previously discovered coalescence-induced binary droplet jumping, the reported mechanism represents a more general capillary-inertial dominated transport mode coupled with particle/droplet properties and is typically mediated by rotation in addition to translation. Through wetting and momentum analyses, we show that transport physics depends on particle/droplet density, size, and wettability. The observed mechanism presents a simple and passive pathway to achieve self-cleaning on both artificial as well as biological materials as confirmed here with experiments conducted on butterfly wings, cicada wings, and clover leaves. Our findings provide insights into particle-droplet interaction and spontaneous particulate transport, which may facilitate the development of functional surfaces for medical, optical, thermal, and energy applications.

Coalescence-Induced Droplet Jumping on Honeycomb Bionic Superhydrophobic Surfaces.

Condensation-induced jumping of droplets on superhydrophobic surfaces has received extensive attention because of its great potential for applications in areas such as condensation enhancement and self-cleaning. However, the jumping efficiency of droplets on flat superhydrophobic surfaces is very low, and there is no reliable means of achieving efficient droplet jumping on large scales, which greatly limits its application. To this end, we developed a class of honeycomb bionic superhydrophobic surfaces (HBSS) that enable reliable and efficient droplet jumping on a large scale for the first time and performed experimental and simulation studies on droplet condensation and jumping on this kind of surface. Condensation experiments show that condensate droplets on HBSS can be effectively positioned under the influence of gravity and the uniformity of the droplet diameter is ensured, laying the foundation for achieving efficient jumping. The shape and geometric parameters of HBSS have a significant impact on the droplet jumping efficiency, and the maximum dimensionless jumping velocity of droplet jumping was experimentally measured to be 0.747, corresponding to an efficiency of about 45.25%. Combining with the results of simulation calculations, we found that the surface structure of HBSS can promote more of the excess surface energy to net upward kinetic energy along an extremely efficient and simple pathway (direct conversion), thus achieving an energy conversion efficiency of over 45%.

Exploring the Role of Initial Droplet Position in Coalescence-Induced Droplet Jumping: Lattice Boltzmann Simulations

Coalescence-induced droplet jumping on superhydrophobic surfaces with different initial positions was numerically simulated using the 2D multi-relaxation-time (MRT) Lattice Boltzmann method (LBM). Simulation results show that for coalesced droplets with radii close to the structure length scale, the change of initial droplet positions leads to a significant deviation of jumping velocity and direction. By finely tuning the initial droplet positions on a flat-pillared surface, perpendicular jumping, oblique jumping, and non-jumping are successively observed on the same structured surface. Droplet morphologies and vector diagrams at different moments are considered. It is revealed that the asymmetric droplet detachment from the structured surface leads to the directional transport of liquid mass in the droplet and further results in the oblique jumping of the coalesced droplet. In order to eliminate the influence of initial droplet position on droplet jumping probability, a surface with pointed micropillars is designed. It is demonstrated that compared to flat-topped micropillars, a surface with pointed micropillars can suppress the initial droplet position effects and enhance droplet jumping probability. Furthermore, the effect of droplet/structure scale on droplet jumping is investigated. The influence of initial positions on coalescence-induced droplet jumping from the refined surface can be ignored when the droplet scale is larger than three times the structure scale. This study illustrates the role of initial droplet position in coalescence-induced droplet jumping and provides guidelines for the rational design of structured surfaces with enhanced droplet self-shedding for energy and heat transfer applications.

Laplace Pressure Difference Enhances Droplet Coalescence Jumping on Superhydrophobic Structures.

Coalescence-induced droplet jumping has great prospects in many applications. Nevertheless, the applications are vastly limited by a low jumping velocity. Conventional methods to enhance the droplet coalescence jumping velocity are enabled by protruding structures with superhydrophobic surfaces. However, the jumping velocity improvement is limited by the height of protruding structures. Here, we present rationally designed limitation structures with superhydrophobic surfaces to achieve a dimensionless jumping velocity, Vj* ≈ 0.64. The mechanism of enhancing the jumping velocity is demonstrated through the study of numerical simulations and geometric parameters of limitation structures, providing guidelines for optimized structures. Experimental and numerical results indicate that the mechanism consists of the combined action of the velocity vectors' redirection and the Laplace pressure difference within deformed droplets trapped in limitation structures. On the basis of previous research on the mechanisms of protruding structures and our study, we successfully exploited those mechanisms to further improve the jumping velocity by combining the limitation structure with the protruding structure. Experimentally, we attained a dimensionless jumping velocity of Vj* ≈ 0.74 with an energy conversion efficiency of η ≈ 48%, breaking the jumping velocity limit. This work not only demonstrates a new mechanism for achieving a high jumping velocity and energy conversion efficiency but also sheds lights on the effect of limitation structures on coalescence hydrodynamics and elucidates a method to further enhance the jumping velocity based on protruding structures.