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Metallic biomaterials are widely used for clinical applications because of their excellent mechanical properties and good durability. In order to provide essential biofunctionalities, surface functionalization is of particular interest and requirement in the development of high-performance metallic implants. Inspired by the functional surface of natural biological systems, many new designs and conceptions have recently emerged to create multifunctional surfaces with great potential for biomedical applications. This review firstly introduces the metallic biomaterials, important surface properties, and then elaborates some strategies on achieving the bioinspired surface functionalization for metallic biomaterials. [ABSTRACT FROM AUTHOR]

An Mn-steel matrix composite locally reinforced with in situ TiC-TiB2ceramic particulates was successfully fabricated via a self-propagating high-temperature synthesis (SHS) casting route in a Cu-Ti-B4C system with various Cu contents. The effect of the Cu content on wear behavior, wear surface, and wear mechanism of the composite was investigated against an AISI H13 mating disc in similar testing conditions at various applied loads and sliding velocities. Moreover, the phase identification and microstructure of the composite were examined. With the increase in Cu content, the wear resistance of the Mn-steel matrix composite decreases first and then increases. Impressively, the composite with 30 wt% Cu content has the highest wear resistance. The enhanced wear resistance can be attributed to the combination of size of ceramic particulates, number of pores, and strength of the interfacial bonding. The dominant wear mechanisms of the TiC-TiB2ceramic particulate–reinforced Mn-steel matrix are ploughing grooves and delamination wear associated with more abrasion and adhesion. [ABSTRACT FROM AUTHOR]

Abstract: The austenite manganese steel–matrix composites locally reinforced with in situ TiC/TiB2 particulates were successfully fabricated using self-propagating high-temperature synthesis (SHS) reactions in a Cu–Ti–B4C system and the effect of the Cu content during casting has been investigated. The local reinforcing regions in the steel matrix composites mainly consist of TiC, TiB2, Cu and austenite, without any intermediate phases. With the increase in the Cu content, the size of the ceramic particulates in the local reinforcing regions decreases, the interface bonding between reinforcing region and matrix becomes poor and the macro-pores and blowholes in the local reinforcing regions become fewer. Moreover, with the increase in the Cu content, the hardness value decreases monotonically, while the wear resistance of the reinforced region increases first then decreases. [Copyright &y& Elsevier]

Dung beetle leg joints exhibit a remarkable capacity to support substantial loads, which is a capability significantly influenced by their surface microstructure. The exploration of biomimetic designs inspired by the surface microstructure of these joints holds potential for the development of efficient self-locking structures. However, there is a notable absence of research focused on the surface microstructure of dung beetle leg joints. In this study, we investigated the structural characteristics of the surface microstructures present in dung beetle leg joints, identifying the presence of fish-scale-like, brush-like, and spike-like microstructures on the tibia and femur. Utilizing these surface microstructural characteristics, we designed a self-locking structure that successfully demonstrated functionality in both the rotational direction of the structure and self-locking in the reverse direction. At a temperature of 20 °C, the biomimetic closure featuring a self-locking mechanism was capable of generating a self-locking force of 18 N. The bionic intelligent joint, characterized by its unique surface microstructure, presents significant potential applications in aerospace and various engineering domains, particularly as a critical component in folding mechanisms. This research offers innovative design concepts for folding mechanisms, such as those utilized in satellite solar panels and solar panels for asteroid probes. [ABSTRACT FROM AUTHOR]

Beetle femur–tibial joints can bear large loads, and the joint structure plays a crucial role. Differences in living habits will lead to differences in femur–tibial joint structure, resulting in different mechanical properties. Here, we determined the structural characteristics of the femur–tibial joints of three species of beetles with different living habits. The tibia of Scarabaeidae Protaetia brevitarsis and Cetoniidae Torynorrhina fulvopilosa slide through cashew-shaped bumps on both sides of the femur in a guide rail consisting of a ring and a cone bump. The femur–tibial joint of Buprestidae Chrysodema radians is composed of a conical convex tibia and a circular concave femur. A bionic structure design was developed out based on the characteristics of the structure of the femur–tibial joints. Differences in the failure of different joint models were obtained through experiments and finite element analysis. The experimental results show that although the spherical connection model can bear low loads, it can maintain partial integrity of the structure and avoid complete failure. The cuboid connection model shows a higher load-bearing capacity, but its failure mode is irreversible deformation. As key parts of rotatable mechanisms, the bionic models have the potential for wide application in the high-load engineering field. [ABSTRACT FROM AUTHOR]

As promising candidates in the field of artificial muscles, ionic‐polymer–metal composites (IPMCs) still cannot simultaneously provide large deformations and fast responses, which has limited their practical applications. In this study, to overcome this issue, a Nafion‐based IPMC with high‐quality metal electrodes is fabricated via novel isopropanol‐assisted electroless plating. The IPMC exhibits a large tip displacement (35.3 mm, 102.3°) under a low direct‐current driving voltage and ultrafast response (>10 Hz) under an alternating‐current (AC) voltage. Furthermore, the simultaneous integration of a large deformation and fast response can be achieved by the IPMC under a high‐frequency (19 Hz) AC voltage, where the largest bending amplitude is 5.9 mm and the highest bending speed reaches 224.2 mm s−1 (596.2° s−1). Additionally, the lightweight IPMC exhibits a decent load capacity and can lift objects 20 times heavier. The outstanding performances of the Nafion IPMC are demonstrated by mimicking biological motions such as petal opening/closing, tendril coiling/uncoiling, and high‐frequency wing flapping. This study paves the way for the fabrication of lightweight actuators with simultaneous large displacements and fast responses for promising applications in biomedical devices and bioinspired robotics. [ABSTRACT FROM AUTHOR]

• High water content ionic-polymer-metal composites (IPMCs) actuators are fabricated. • The IPMC actuators can realize great and stable deformation driven by DC voltage. • Guide-grapple robots and microarchitectures of robotic metamaterials are developed. • A finite element simulation approach to model 3D structures with IPMC actuators. Ionic-polymer metal composites (IPMCs) actuators show great potential for soft robots due to their large deformations and fast responses at low voltage. However, realizing large and stable deformation remains a challenge since the existence of back relaxation phenomena. Herein, we report high-performance IPMCs actuators fabricated via solution-casting and isopropanol-assisted electroless plating methods. The actuator exhibits extremely large bending deformation (125°) and ultrafast initial response speed (1.09 % s−1 bending strain rate) within one second of the start time under the DC voltage of 3 V. Furthermore, the actuator exhibits no significant back relaxation, even when it lifts objects 11 times heavier and holds up for more than 695 s. The outstanding properties of the actuator are demonstrated by various soft robots, including a guide-grapple robot and a microarchitecture for robotic metamaterials, and a finite element simulation approach is proposed to model the robotic metamaterials. This study offers a viable means for developing high-performance artificial muscles without back relaxation for promising applications in biomedical devices, robotic metamaterials, and soft robotics. [ABSTRACT FROM AUTHOR]

Utilizing surface micropillar arrays to elevate Leidenfrost temperature (T LT) is an effective alternative for optimizing the spray cooling efficiency. However, the intricate nonlinear relationship between micropillar structure parameters and multi-phase heat transfer behavior of Leidenfrost effects remains poorly understood. This study uses an efficient and robust CFD-aided method for evaporation modelling and heat transfer optimization, mechanistically elucidated that the surface micro/nanostructures affected on interfacial heat flux and boiling transition at the high-temperature surfaces (above and below T LT). The method is verified experimentally, and contributed to develop a functional relationship between droplet impact velocity v and micropillar arrays height H with T LT. The interfacial mechanism manifests that vapors generated by droplet evaporation persistently accumulate to regulate Leidenfrost effect, compromising the shape and dynamic spreading behavior of impacting droplets. Irrespective of the proximity to Leidenfrost point, an increase in micropillar height significantly enhances heat transfer, with more pronounced effects observed at higher surface temperatures. Simultaneously, the synergy of micropillar height and surface temperature also directly inhibits Leidenfrost effect and thereby facilitating the contacting heat transfer. Notably, the heat transfer optimizations exhibiting the favorable heat transfer increased the heat transfer by 44.89% at a surface temperature of 413.15 K, and by 92.22% at 573.15 K. [ABSTRACT FROM AUTHOR]

• A double-sided microplate array (DMPA) with bio-inspired Janus surfaces to fulfill droplet multi-dimensional manipulation. • Leveraging variation in superhydrophobicity and low adhesion of convex hull for droplet directional transport in plane. • The adhesion switchable transition of surface striped structure to realize droplet capture/release for long-distance multi-dimensional transport. • Developing a magnetic-responsive droplet switch. Achieving precise and rapid droplets manipulation in versatile directions transport remains a considerable challenge, however adhesion switchable transitions deemed to be rather serviceable. Here, a double-sided microplate array (DMPA) with bio-inspired Janus surfaces, is proposed to fulfill adjustable adhesion through surface wettability switching and microplate dynamic deformation, thereby executing the droplet multi-dimensional manipulation in response to dynamic magnetic field. The triple-coupled bio-inspired Janus surfaces are newly designed with a convex hull and striped structure respectively, inspired by the respiratory ciliary motion and surface properties of lotus and rice leaves. Leveraging variation in superhydrophobicity and low adhesion of convex hull side on Janus surface, diverse droplet directional transports are achieved in plane, such as high-speed horizontal transport (120 mm/s and 500 µL), anti-gravitational climbing (inclined by 15°), and selective droplet orientation. The adhesion switchable transition of surface striped structure on other side is predominated by solid–liquid contact lines evolution resulting from microplate bending deformation, realizing droplet capture/release for long-distance multi-dimensional transport. Concurrently, a magnetic-responsive droplet switch is developed based on multi-directional droplet manipulation, demonstrating enormous potential for practical application. [ABSTRACT FROM AUTHOR]

• A humidity-driven monolayer film actuator based on agarose are fabricated. • The film actuator can rapidly deform and roll under humidity-driven conditions. • Surface patterning of films can enhance rolling speed and alter the rolling mechanism. • Application potentials in smart bionic devices and soft crawling robots. The widespread availability and easy accessibility of humidity make it essential to explore simple and low-cost methods to prepare structurally and materially efficient humidity-driven actuators with spontaneous and continuous locomotion to facilitate the application of bionic devices, intelligent sensors, and soft robots. Herein, this paper reports a humidity-driven monolayer film actuator. It is self-assembled from agarose (AG) and graphene oxide (GO) modified with polyvinylpyrrolidone (PVP), referred to as PGO, using a simple casting method. The PGO/AG composite film actuator exhibits an ultra-fast humidity response time (124.58° s−1) and recovery time (18.87° s−1), enabling rapid rolling locomotion driven by water evaporation. Notably, the programmable surface patterning of the PGO/AG composite film actuator with graphite results in a shorter single rolling time (0.43 s) and a faster rolling speed (28.73 mm s−1). Based on these advantages, the PGO/AG film actuator can mimic the opening and closing of flowers, mimosas, and fast-crawling robot driven by periodic water vapor (9.9 body length min−1). This finding provides new insights into the design of multifunctional actuators based on humidity-driven films. [ABSTRACT FROM AUTHOR]

In this paper, experimental and numerical methods are presented to describe the hydrodynamic process of the vibration-induced detachment of a droplet from a superhydrophobic surface. We conduct the investigation of the droplet dynamics under various vibration and impact parameters, from an energy conversion perspective. In particular, the energy dissipation that occurs following the droplet impact is analyzed quantitatively. We identify three viewpoints on vibration-induced droplets. Firstly, the phase angle is the dominant factor in characterizing the droplet morphology evolution and energy dissipation on a vibrating surface. The law governing the initial phase angle is affected by the vibration frequency, while the intensity is affected by the vibration amplitude. Secondly, the energy dissipation is positively correlated with the maximum spreading diameter and impact velocity. A larger initial diameter tends to produce a longer contact time. Finally, the central jet formation depends heavily on the upward velocity of the concave liquid, under the peculiar morphology of a vibration-induced droplet. For all these effects, up to 60% of the total energy is squandered during impact, while the surface energy remains almost constant. Much of the droplet's kinetic energy is lost in resisting the viscous force of the substrate. • The droplet dynamics under various vibration and impact parameters are examined. • The phase angle is dominant in characterizing morphology and energy dissipation. • The central jet phenomenon depends on the upward velocity of the concave liquid. • Much of the kinetic energy is lost in resisting the viscous force of the substrate. [ABSTRACT FROM AUTHOR]

Kingfishers during rain remain dry even standing still on a branch, because of converting normally vertical impacting to horizontal droplets transport, and bioinspired applications with the mixed-wettability surface exhibit the maximum horizontal transport distance by up to 6.2 D 0. [Display omitted] Kingfishers stand on a branch, and raindrops tumble translationally from feathers during raining, enlightening functional surfaces design and liquid transport control. Far-ranging studies on oriented transportation are confined to vertical impacting, which is, to date, in-depth philosophy of horizontal droplets transport on motionless surface deems to be rather serviceable. This study, employed mixed-wettability surface inspired by kingfishers' feather, occurs on directional transportation issues, such as the synergies of wettability-controlled, driving force and transportation capability. Here we conduct both experimental testing and CFD-aided numerical modelling to reproduce the asymmetric bouncing and directional transport phenomena. We found that the anisotropic surface manipulates to convert normally vertical impacting to horizontal droplets transport. Law of the thrown droplet, on the other hand, is predominated by the wettability-controlled surface, while the coexistence of contact angle difference and surface offset location cooperatively dictates the intensity and patterns of the thrown droplet. Of all these factors, the post-optimized surfaces are designed first and then the regime map of transportation pattern is elaborated. Results manifest that the elements induce the maximum horizontal transport distance by up to 6.2 D 0 , and first desorption time is only 7.8 ms. The findings shed light on engineering design principles that can pave the way for novel applications in anti-icing, lubrication, and spray cooling. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D print antichiral structures with auxetic effects and varied Poisson's ratios. • Shape memory in metamaterials allows adjustable mechanics for form adaptation. • Auxetic metamaterials with electrodes ensure fit, breathability, and signal quality in wearables. Research on creating special structures with a negative Poisson's ratio, known as auxetic metamaterials, is widely conducted for potential applications in flexible electronics, aerospace, biomedicine, and other fields. Auxiticity is the phenomenon of transverse expansion that occurs when stretched longitudinally. However, conventional metamaterial tunable properties have certain limitations, mainly in the form of limited Poisson's ratio tuning range and transverse deformation. In this work, a series of symmetric antichiral auxetic structures with significant auxetic effect and low Poisson's ratio of −5 are designed and fabricated by 3D printing. Based on the manipulating of unit parameters and the use of shape memory polymers, the auxetic metamaterials exhibit tunable mechanical properties and programmable shape memory behaviors. Owing to these features, the auxetic metamaterials are demonstrated to achieve excellent shape-fitting and size-fitting capabilities, which are followed by expanding in a full range to contact any objects (due to auxiticity) and then contract to conform their shapes (due to shape memory). By integrating flexible electromyography(EMG) electrodes, the shape memory auxetic metamaterials can be used as self-adaptive wearable devices to fit with human limbs, which can ensure the good attachment, high signal to Noise Ratio (SNR), and breathability when collect EMG signals. [ABSTRACT FROM AUTHOR]

Epoxy resin (EP) as common polymers have attracted much attention in the field of shape memory materials due to their excellent properties. However, epoxy-based shape memory polymers suffer from a trade-off between strength, toughness, variable stiffness capability and shape memory properties, and thus are subject to significant limitations in their applications. In this paper, we propose a method to prepare epoxy composites with high strength and toughness and high shape memory properties by introducing a lot of hydrogen bonds. Hydrogen bonding is generated through polycaprolactone (PCL) induced EP phase separation. A low melting point alloy (L) was also added to enhance the shape memory properties of the composites. The synthesis mechanism of EP and the formation mechanism of hydrogen bonding were revealed. The effects of the introduction of hydrogen bonding on the mechanical properties, stiffness and shape memory properties of the composites were investigated. New ideas and design directions are provided for the optimisation of modification of high-performance shape memory epoxy resins. [Display omitted] • Enhanced mechanical properties of resins achieved by induced phase separation. • Efficient dispersion of low melting point alloys in resins. • The mechanism of the effect of hydrogen bonding on resin properties is revealed. [ABSTRACT FROM AUTHOR]

• A 3D CFD numerical simulation coupled VOF model with an amended evaporation model, combined with high-speed video experimental testing, is conducted. • The law of the dynamic Leidenfrost point (T DLT) is predominated by vapor layer thickness and shape changes. • The empirical correlation of T DLT with Weber number (We) was as follows: T D L T = 376.65 + 84.45 × W e 0.22 . • The higher T w promoted the formation of the vapor layer, resulting in a decline in heat transfer efficiency. • The larger v inhibited the formation of the vapor layer and enhance interfacial heat transfer. This study, a novel three-dimensional (3D) method is developed to address the Leidenfrost effect issues with a focus on the synergies of droplet velocity (v) and surface temperature (T w). Here, we proposed a 3D computational fluid dynamics numerical simulation that combines a VOF model and an amended evaporation model and performed high-speed video testing for capturing vapor dynamics details and distinguish anisotropic heat transfer on a high-temperature surface near the Leidenfrost point. The results revealed that the law of the dynamic Leidenfrost point (T DLT) was predominated by changes in the thickness and shape of the vapor layer. Additionally, coexistence of v and T w produced a vapor layer, instantly disentangling the boiling state and initiating a gradual change from contact boiling to film boiling, with v affecting the boiling state transition and delaying buildup of the vapor layer aggregation. We determined the empirical correlation of T DLT with the Weber number (We) as follows: T D L T = 376.65 + 84.45 × W e 0.22 . Moreover, the high T w promoted vapor layer formation, thereby decreasing the heat transfer efficiency, whereas the large v inhibited vapor layer formation and enhanced interfacial heat transfer. These findings contribute to a better understanding of the theoretical basis for inhibiting the Leidenfrost effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • PVA-LS hydrogels with various path structures were low-temperature 3D printed. • Silver layer on hydrogel surface realized high conductivity and sensitivity. • Electrical sensing mechanisms were disclosed. Flexible strain sensors are core components of wearable strain sensors, and they have attracted much attention because of their applications for electronic skin and monitors of human activity. However, hydrogel-based strain sensors are greatly limited by the trade-offs between mechanical performance, electrical sensing properties and diverse structures. In this paper, we present a facile approach for preparing conductive hydrogels with good mechanical properties, outstanding electrical sensing properties and complex structures. First, a low-temperature 3D printer was designed and fabricated in this laboratory to prepare lignosulfonate/poly(vinyl alcohol) hydrogels with complex structures. The hydrogels with a 30° angle between adjacent layers showed the best optimal tensile properties. Then, extremely thin and dense silver layers were prepared by reducing silver on their surfaces using a two-step immersion process to obtain electrical sensing functionality. The process of preparing layers of reduced silver was carefully analyzed according to the Lamer model, and the resulting silver layers showed relatively high conductivity of 8571 S/cm. By changing the print path angles of the upper surface, hydrogels were prepared with different sensitivities and strain ranges. The maximum sensitivity and widest strain range were 177.65 and 0–55%, respectively. The corresponding hydrogels showed durable sensing performances in various tensile strain and long-term cyclic loading and relaxation tests. The sensing mechanisms of the hydrogels were the opening and closing of microcracks in the silver layers located in the print paths and the gaps between adjacent print paths. The sensors composed of conductive hydrogels successfully detected subtle vibrations in strains and various human activities, indicating their great potential for applications in monitors for human health and soft robotics. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronics have good gas permeability, stretchability, and flexibility. • The combination with AgNWs is by a self-assembled method. • The electronics have good conformal ability and excellent fatigue resistance. • The electronics device can accomplish high-quality biopotential measurement. On-skin electronics offers a noninvasive method for continuous and stable signal monitoring, which has played a significant role in healthcare and rehabilitation engineering. However, most present on-skin electronicses are highly restricted by their gas permeability and stretchability due to the materials, fabrication process, and cost. This study develops gas-permeable and stretchable on-skin electronics fabricated via a gradient porous elastomer and self-assembled silver nanowires. The introduction of a gradient porous structure offers the elastomer substrate a good water vapor permeability of 3073.3 g day−1 m−2, which is much higher than the average evaporation rate of water vapor on human skin (432 g day−1 m−2). Additionally, the examined electronic device has no adverse effects on the skin and possesses good stretchability and flexibility (110%, 0.07778 MPa). In addition, it offers excellent fatigue resistance (0.70% electrical resistance change within 1000 stretch cycles). The electronic device achieves conformal and comfortable contact with human skin for a long period of wearing and accomplishes high-quality biopotential measurement with a high signal-to-noise ratio (SNR) during electromyography (EMG) signal detection. The proposed simple fabrication process may supply inspiration for new on-skin electronics used in biological signal detection and rehabilitation engineering. [ABSTRACT FROM AUTHOR]

The hydrogel could exhibit fast antibacterial activity before biodegradation, and then the infected wound could be angiogenesis and healed after the hydrogel biodegradation. [Display omitted] • The halogen-free imidazolium poly(ionic liquids) were synthesized as antibacterial agents. • The hydrogel dressings contained halogen-free imidazolium poly(ionic liquids) and deferoxamine. • The hydrogel dressings exhibited fast antibacterial activity and angiogenesis. • The hydrogel dressings could programable repairing full-thickness skin defect wound. Full-thickness skin defect wound infection seriously threatens the life and health of patients. Highly efficient antibacterial activity and angiogenesis after injury are critical for the wound healing process. In this work, we first designed various of halogen-free imidazolium poly(ionic liquids) (PILs) as the antibacterial agents, and selected the highest efficient antibacterial PIL. Then, we fabricated hyaluronic acid/poly(ethylene glycol)/PILs semi interpenetrating polymer network (semi-IPN) wound dressings by Diels-Alder (DA) click reaction, and deferoxamine (DFO) which promoted angiogenesis was grafted into the hydrogel wound dressings. In vitro and in vivo assays respectively evaluated the fast antibacterial property of the hydrogels against Escherichia coli and Staphylococcus aureus at skin infected wound areas. With the hydrogels enzymatic degradation by hyaluronidase, the degradation solution could reduce inflammation, promote angiogenesis and wound healing due to the continuous releasing of DFO and PIL. The programable hydrogel degradation protocol provided a new strategy for rapid full-thickness skin defect wound healing in the clinic application. [ABSTRACT FROM AUTHOR]

The bioinspired superhydrophobic surface (SHS) demonstrates the capability in terms of anti-icing/de-icing, however, the mechanisms of micro−/nanostructure on interfacial heat transfer and phase change are inadequately revealed during freezing. A comprehensive solution method, considers a modified roughness, texture, and thermal properties of SHSs material, is developed in this study. This method, coupled Level Set-Volume of Fluid (CLSVOF) with solidification model and combined freezing experiments, captures the ice-liquid-gas interface change and anisotropic interfacial heat exchange. Numerical and experimental results in frozen nucleation illustrate that the micro−/nanostructure blocks heterogeneous heat transfer via the stored air, extended the freezing time and the freezing delay rate is 194%. Accordingly, the numerical model between freezing time (t) and surface temperature (T surface), is following power function t = 959.42 × (273.15 − T surface)−0.777. Moreover, the moving droplets overcome the freezing adhesion through shortening the contact time then to limit the heat exchange process, allowing their self-removal before freezing. The de-icing analysis confirms that the larger contact angle (CA) and cavitation structure jointly affect the solid-liquid contact area, and the bionic surface in this study reduces the adhesion strength of frozen droplets by 4 times. • A numerical method during freezing, is developed. • The effects of micro−/nanostructure on interfacial heat transfer and phase change are adequately resolved. • The sample surface extended the delay rate and reduced the adhesion strength of frozen droplets. • The larger CA and cavitation structure of SHS jointly affected the anti-icing/de-icing. [ABSTRACT FROM AUTHOR]

[Display omitted] • A superhydrophobic surface that can switch between high-adhesion superhydrophobic and hydrophobic states is fabricated. • The surface can be used as a droplet capturer or reaction platform for droplet manipulation. • The surface also dramatically demonstrates the application potential in friction control. Superhydrophobic surfaces with structure-dependent switchable wettability have recently drawn considerable attention due to their special applications in droplet manipulation, rewritable liquid patterns, friction control, etc. However, it still remains a great challenge for developing tunable superhydrophobic surfaces with multiple functions including friction control through a facile strategy. Here, we apply a templating approach to fabricate switchable superhydrophobic surfaces that can reversibly transit between high-adhesion superhydrophobic and hydrophobic states by dynamically controlling the morphology of the micro/nanostructures. Notably, due to the dynamically controllable micro/nanostructures and wettability, the superhydrophobic surface shows multiple functions. The superhydrophobic surface under different wetting states can serve as a droplet capturer or reaction platform to achieve droplet manipulation. Moreover, the friction coefficient of the superhydrophobic surface can be switched between ∼ 0.4 and ∼ 0.13, demonstrating the application potential in friction control. This work offers a promising multifunctional superhydrophobic platform with dynamically controllable morphology of micro/nanostructures and wetting behaviors for the applications of droplet manipulation and friction control. [ABSTRACT FROM AUTHOR]

Objective: This study prepared vascularized dermal fat flaps and introduced a local split-thickness skin graft from an in situ cutaneous area cutaneous area to manage forearm flap donor sites and evaluated the esthetic and functional outcomes post-operatively. From July 2020 to June 2023, 13 patients with soft tissue defects in Oral and Maxillary Area were repaired with tvascular forearm dermal fat flap. There were 8 males and 5 females, aged from 42-71 years. The flaps ranged from 8 cm×7 cm to 7 cm×5 cm in size. The donor site defects were covered by local split-thickness skin graft from the in situ skins. The color matching degree, surgical scars, ranges of wrist movement and hand sensations in donor forearms were assessed at 6 months after surgery. Results: The tvascular forearm dermal fat flaps for 15 cases all survived. All the local split-thickness skin grafts transplanted with this technique showed primary healing. The follow-up period for 6 months, Donor site exhibited suitabler color matching and there was not severe complications. Conclusion: The vascularized dermal fat flap provides an alternative to conventional forearm flap harvest, which enables primary donor site closure with reduced rates of delayed donor site healing. The vascularized dermal fat flap is a relatively reliable repair method for soft defects in Oral and Maxillary Area., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)