Intramuscular versus intradermal botulinum toxin for forehead wrinkles: a review of side effects and efficacy.

Botulinum toxin type A (BTA) is a neurotoxin used for both cosmetic and non-cosmetic purposes. BTA is commonly administered as an intramuscular injection to treat wrinkles. However, when it comes to treating forehead wrinkles, intramuscular injection is associated with a greater rate of ptosis. Intradermal injection is currently thought to be a better alternative. We searched PubMed and Google Scholar for research articles published between 1989 and 2023 using the following keywords: "intradermal," "intramuscular," "botulinum toxin," and "forehead wrinkle." The search yielded three randomized controlled trials and a double-blind, split-face case report on 58 patients. We found that although intradermal and intramuscular injections have symmetrical anti-wrinkle effects, the former results in a lower rate of ptosis and a greater degree of pain.

Photochemical Design for Diverse Controllable Patterns in Self-Wrinkling Films.

Harnessing the spontaneous surface instability of pliable substances to create intricate, well-ordered, and on-demand controlled surface patterns holds great potential for advancing applications in optical, electrical, and biological processes. However, the current limitations stem from challenges in modulating multidirectional stress fields and diverse boundary environments. Herein, this work proposes a universal strategy to achieve arbitrarily controllable wrinkle patterns via the spatiotemporal photochemical boundaries. Utilizing constraints and inductive effects of the photochemical boundaries, the multiple coupling relationship is accomplished among the light fields, stress fields, and morphology of wrinkles in photosensitive polyurethane (PSPU) film. Moreover, employing sequential light-irradiation with photomask enables the attainment of a diverse array of controllable patterns, ranging from highly ordered 2D patterns to periodic or intricate designs. The fundamental mechanics of underlying buckling and the formation of surface features are comprehensively elucidated through theoretical stimulation and finite element analysis. The results reveal the evolution laws of wrinkles under photochemical boundaries and represent a new effective toolkit for fabricating intricate and captivating patterns in single-layer films.

Hollow UiO-66-NH2 encapsulated Pd catalysts for highly selective hydrogenation of furfural to furfuryl alcohol.

The selective hydrogenation of furfural (FFA) to furfuryl alcohol (FA) is regarded as attractive transformation to achieve the sustainable synthesis of value-added chemicals from biomass resources. However, the conventional supported catalysts are significantly restricted by their narrow pore size, ununiform dispersion and easy leaching or aggregation of catalytic sites. Herein, we designed hollow UiO-66-NH2 as the support to encapsulate Pd nanoparticles (Pd@H-UiO-66-NH2) to achieve the highly active and selective conversion of FFA to FA. Benefiting from the void-confinement effect and substrate enrichment of hollow structure, as well as the surface wrinkles, the as-prepared catalyst Pd@H-UiO-66-NH2 exhibited 96.8 % conversion of FFA with satisfactory selectivity reaching up to 92.4 % at 80 °C, 0.5 MPa H2 in isopropanol solvent within 6 h. More importantly, as-prepared Pd@H-UiO-66-NH2 catalyst exhibited excellent long-term stability, as well as good universality toward a series of hydrogenation of unsaturated hydrocarbons.

Efficacy and Safety of Skin Radiance Collagen on Skin and Hair Matrix: A Placebo-Controlled Clinical Trial in Healthy Human Subjects.

Purpose: Collagen supplements are rising in the market as collagen has been demonstrated to be an important protein in the human aging process. Also, it is safe and easily absorbed in the body. Hence the aim of this study was to examine the effectiveness and safety of a collagen and antioxidant-rich treatment compared to a placebo in relation to various skin and hair indicators in healthy adult human subjects. Patients and Methods: Forty healthy adult non-pregnant/non-lactating women (aged 38-50 years) provided their informed consent in writing before their participation. Skin Radiance Collagen (SRC) treatment and a placebo were assessed for efficacy before application on Day 1, and post-application on Days 28 and 56, to measure changes in skin elasticity, hydration, brightness, pigmentation; texture, wrinkles, dryness, smoothness, fine lines, changes in the crow's feet region; as well as hair strength and hair fall. Results: It was observed after 56 days that therapy with SRC, compared to placebo, produced a substantial effect on reduction of wrinkle depth and fine lines by 48.11% and 39%, respectively, with p-value <0.01 in the test group. There was a 15.69% improvement in skin hydration observed and 28% reduction in hair fall with p-value <0.01. Conclusion: SRC, a combination of collagen with hyaluronic acid (HA), biotin, and vitamins C and E, showed a significant improvement in skin and hair health, including improvements in skin elasticity, skin hydration, reduction in crow's feet area wrinkles and fine lines, hair fall, and decrease in roughness, leading to improved skin texture. Vitamin C in the formulation also acts as a collagen builder for the body and helps in preventing oxidative stress in the body. The test treatment SRC was found to be efficacious and safe in healthy human adult subjects.

Biomimetic design of micro- and nano-wrinkle wood surface via coating reinforced with hyperbranched polymer grafted cellulose nanofibers for skin-tactile performance.

Inspired from human skin, micro- and nano-wrinkled wood surface with skin-tactile performance was designed and developed using a waterborne UV-curable polyurethane acrylate coating and cellulose nofibers (CNF). To further improve the properties, the CNF was diacetylated to D-CNF and further grafted with a hyperbranched polymer containing rich end amino groups (HB-CNF). The surface structure and chemical reactions were characterized, and the skin-tactile performance of the coating was comprehensively investigated. The HB-CNF exhibited excellent dispersion in the coating, and extensive reactions occurred between the two through the -NH2 and terminal -NCO groups, resulting in much improved mechanical properties and durability. Micro-wrinkles with a width of approximately 12-15 µm and a height of 8-14 µm were created, and nano-protrusions of wrinkles ranging from to 50-100 nm were obtained. The coated surface was hydrophobic and exhibited high resilience after compression, with a gloss of 3.3 GU at an incident angle of 60° and a static friction coefficient of 0.26, both of which were similar to those of human skin. The results presented an effective strategy for high-performance wood products with a good feeling, which is helpful to improve the market competitiveness and meet the people's pursuit of a better life.

Oral consumption of Bonito fish-derived elastin peptide (VGPG Elastin® ) improves biophysical properties in aging skin: A randomized, double-blinded, placebo-controlled study.

BACKGROUND: Recent in vitro and in vivo studies have suggested that the elastin peptide improves the skin's biophysical properties, enhancing the proliferation of fibroblasts and elastin synthesis, resulting in anti-aging properties. Therefore, we conducted a randomized, double-blinded, placebo-controlled study to clinically evaluate the effect of elastin peptide intake on human skin. MATERIALS AND METHODS: Healthy adult participants (N = 100) were randomly assigned to receive a test product containing 100 mg of Bonito elastin peptide (VGPG Elastin® ) or placebo. In this study, all participants were Asian from Korea. The parameters of skin wrinkles, hydration, and brightening (melanin index) were measured at baseline and 4, 8, and 12 weeks after intervention. RESULTS: The average skin roughness, maximum peak-to-valley values, maximum peak height of the wrinkle, maximum valley depth of the wrinkle, average maximum height of the wrinkle, and eye wrinkle volume improved considerably in the test group compared with the placebo after 12 weeks of intervention. Skin hydration was enhanced, and the melanin index was significantly lower in the test group than in the placebo group. No participant experienced adverse events related to the test product. CONCLUSION: Oral consumption of Bonito elastin peptide (VGPG Elastin®) reduced fine wrinkles, enhanced skin moisture, and decreased melanin index without significant adverse effects and may be a promising anti-wrinkle, anti-dryness, and anti-pigmentation treatment.

Strain Engineering: Perfecting Freestanding Perovskite Oxide Fabrication.

Freestanding oxide membranes provide a promising path for integrating devices on silicon and flexible platforms. To ensure optimal device performance, these membranes must be of high crystal quality, stoichiometric, and their morphology free from cracks and wrinkles. Often, layers transferred on substrates show wrinkles and cracks due to a lattice relaxation from an epitaxial mismatch. Doping the sacrificial layer of Sr3 Al2 O6 (SAO) with Ca or Ba offers a promising solution to overcome these challenges, yet its effects remain critically underexplored. A systematic study of doping Ca into SAO is presented, optimizing the pulsed laser deposition (PLD) conditions, and adjusting the supporting polymer type and thickness, demonstrating that strain engineering can effectively eliminate these imperfections. Using SrTiO3 as a case study, it is found that Ca1.5 Sr1.5 Al2 O6 offers a near-perfect match and a defect-free freestanding membrane. This approach, using the water-soluble Bax /Cax Sr3-x Al2 O6 family, paves the way for producing high-quality, large freestanding membranes for functional oxide devices.

Dietary Isoeugenol Supplementation Attenuates Chronic UVB-Induced Skin Photoaging and Modulates Gut Microbiota in Mice.

Photoaging, the primary cause of skin aging damage, results from chronic ultraviolet (UV) exposure, leading to dryness and wrinkle formation. Nutritional intervention has emerged as a practical approach for preventing and addressing the effect of skin photoaging. The primary aromatic compound isolated from clove oil, isoeugenol (IE), has antibacterial, anti-inflammatory, and antioxidant qualities that work to effectively restrict skin cancer cell proliferation. This investigation delved into the advantages of IE in alleviating skin photoaging using UVB-irradiated skin fibroblasts and female SKH-1 hairless mouse models. IE alleviated UVB-induced photodamage in Hs68 dermal fibroblasts by inhibiting matrix metalloproteinase secretion and promoting extracellular matrix synthesis. In photoaged mice, dietary IE reduced wrinkles, relieved skin dryness, inhibited epidermal thickening, and prevented collagen loss. Additionally, the intestinal dysbiosis caused by prolonged UVB exposure was reduced with an IE intervention. The results of Spearman's analysis showed a strong correlation between skin photoaging and gut microbiota. Given the almost unavoidable UVB exposure in contemporary living, this research demonstrated the efficacy of dietary IE in reversing skin photoaging, presenting a promising approach to tackle concerns related to extrinsic skin aging.

Optimizing Botulinum Toxin A Administration for Forehead Wrinkles: Introducing the Lines and Dots (LADs) Technique and a Predictive Dosage Model.

This study introduces the Lines and Dots (LADs) technique, a new approach for administering botulinum toxin type A (BoNT-A) in treating forehead wrinkles. (1) Background: BoNT-A application patterns in the forehead often rely solely on the anatomy of the frontalis muscle. The LADs technique proposes a combination of anatomical features with nerve pathways. (2) Methods: The technique employed a grid system aligned with the supraorbital and supratrochlear nerve pathways and used an electronic acupuncture pen for validation. This study analyzed treatment outcomes for efficacy and safety and proposed a predictive model for BoNT-A dosage. (3) Results: LADs was associated with a high satisfaction rate and low side effect incidence. The predictive model followed BoNT-A Units=0.322×Muscle Pattern Code+1.282×Line Type Code+2.905×Severity Pre-Treatment+3.947. (4) Conclusions: The LADs technique offers an alternative approach to treating forehead wrinkles, optimizing efficacy while minimizing the BoNT-A dose required.

Annurca Apple Oleolite as Functional Ingredient for the Formulation of Cosmetics with Skin-Antiaging Activity.

The identification of natural remedies for the management of the skin aging process is an increasingly growing issue. In this context, ursolic acid (UA), a ubiquitous molecule, mainly contained in Annurca apple (AA) fruit, has demonstrated valuable cosmetic potential. To this end, in the current study, the AA oleolite (AAO, extract in sunflower oil containing 784.40 ± 7.579 µg/mL of UA) was evaluated to inhibit porcine elastase enzymatic reactions through a validated spectrophotometric method. AAO has shown a valuable capacity to contrast the elastase enzyme with a calculated IC50 of 212.76 mg/mL, in comparison to UA (IC50 of 135.24 µg/mL) pure molecules and quercetin (IC50 of 72.47 µg/mL) which are used as positive controls. In this context and in view of the valuable antioxidant potential of AAO, its topical formulation with 2.5% (w/w) AAO was tested in a placebo-controlled, double-blind, two-arm clinical study on 40 volunteers. Our results indicated that after 28 days of treatment, a significant reduction of the nasolabial fold (-7.2 vs. baseline T0, p < 0.001) and forehead wrinkles (-5.3 vs. baseline T0, p < 0.001) were registered in combination with a valuable improvement of the viscoelastic skin parameters, where skin pliability/firmness (R0) and gross elasticity (R2) were significantly ameliorated (-13% vs. baseline T0, p < 0.001 for R0 and +12% vs. baseline T0, p < 0.001 for R2). Finally, considering the positive correlation between skin elasticity and hydration, the skin moisture was evaluated through the estimation of Trans epidermal water loss (TEWL) and skin conductance.

Potential Role of Dietary Salmon Nasal Cartilage Proteoglycan on UVB-Induced Photoaged Skin.

New supplements with preventive effects against skin photodamage are receiving increasing attention. This study evaluated the anti-photoaging effects of salmon nasal cartilage proteoglycan (SPG), acting as a functional material for skin health. We administered SPG to in vitro and in vivo models exposed to ultraviolet B (UVB) radiation and assessed its moisturizing and anti-wrinkle effects on dorsal mouse skin and keratinocytes and dermal fibroblasts cell lines. These results showed that SPG restored the levels of filaggrin, involucrin, and AQP3 in the epidermis of UVB-irradiated dorsal skin and keratinocytes, thereby enhancing the keratinization process and water flow. Additionally, SPG treatment increased the levels of hyaluronan and skin ceramide, the major components of intercellular lipids in the epidermis. Furthermore, SPG treatment significantly increased the levels of collagen and procollagen type 1 by down-regulating matrix metalloproteinase 1, which play a crucial role in skin fibroblasts, in both in vitro and in vivo models. In addition, SPG strongly inhibited mitogen-activated protein kinase (MAPKs) signaling, the including extracellular signal-regulated kinase, c-Jun N-terminal kinase (JNK), and p38. These findings suggest that dietary SPG may be an attractive functional food for preventing UVB-induced photoaging. And this SPG product may provide its best benefit when treating several signs of skin photoaging.

Double-blind, vehicle-controlled clinical investigation of peptide OS-01 for skin rejuvenation.

INTRODUCTION: Senescent cells contribute to age-related tissue deterioration, including the skin, which plays important roles in overall health and social interactions. This study aimed to assess the effects of the senotherapeutic peptide, OS-01 (a.k.a. Pep 14), on skin. METHODS: A 12-week split-face, double-blinded, vehicle-controlled study involving 22 participants was conducted. The OS-01-containing formulation was applied to one side of the face, while the other side received an identical control formulation lacking the peptide. Skin characteristics were assessed using instrumental measurements, expert clinical grading, and subjective questionnaires. RESULTS: Results showed that the OS-01 formulation significantly improved one aspect of skin barrier function, as evidenced by reduced trans-epidermal water loss compared to both baseline and vehicle control. Expert grading and Antera 3D image analysis revealed a reduction in wrinkle appearance and indentation in the periorbital area, and improved skin texture and radiance on both sides of the face, with the OS-01-containing formulation demonstrating superior results. Participants also perceived improvements in skin hydration, smoothness, radiance, and overall appearance. CONCLUSION: The findings suggest that the OS-01 formulation promotes skin health by strengthening the skin barrier, protecting against dehydration, reducing the appearance of wrinkles, and improving skin texture and radiance. These effects are likely attributed to the senotherapeutic properties of OS-01 in reducing cellular senescence and its associated detrimental effects.

Plasma Jet versus Electrocarbonization in the Treatment of Wrinkles of the Upper Palpebral Region.

Background: The plasma jet is a non-surgical and minimally invasive procedure that acts by heating the superficial region of the skin, providing rejuvenation of the region. Objective: We sought to compare the clinical and histological effects of direct plasma jet versus electrocarbonization without plasma in the treatment of wrinkles in the upper palpebral region. Methods: This is a clinical trial in which 20 volunteers participated and divided into two groups: electrocarbonization (EG) and plasma jet (JPG), which were clinically evaluated before and after treatment through evaluation protocols, photographs, and questionnaires. Three treatment sessions were performed in the upper eyelid region with an interval of 30 days. After the treatment, a surgical procedure of upper blepharoplasty was performed on two volunteers to remove a skin fragment and later histological analysis. Results: The JPG showed better clinical responses in rejuvenation. The EG promoted an increase in the number of fibroblasts, the number of blood vessels and the amount of inflammation. The JPG showed an increase in the number of fibroblasts and blood vessels. It was observed that the JPG generated activation of T lymphocytes (CD3), macrophages (CD68), and plasmocytes (CD138); in addition to reducing the number of positive cells for CD57 (NK cells). The satisfaction analysis shows that 100 percent in the JPG considered themselves satisfied with the treatment. Conclusion: We verified that in comparison with electrocarbonization, the use of a direct plasma jet promoted tissue improvement at the histological level, in addition to fewer adverse reactions.

Efficacy and Safety of Type III Collagen Lyophilized Fibers Using Mid-to-Deep Dermal Facial Injections for the Correction of Dynamic Facial Wrinkles.

BACKGROUND: This study aimed to evaluate the therapeutic efficacy and safety of injecting Type III collagen lyophilized fibers into the mid-to-deep layers of the facial dermis to ameliorate dynamic facial wrinkles. METHODS: In this retrospective analysis, clinical data were collected from patients exhibiting dynamic facial wrinkles (encompassing frown lines, forehead lines, and crow's feet) with a wrinkle severity rating scale (WSRS) score of 3 or higher. In the control group, 75 participants received collagen implant injections into the mid-to-deep facial dermal layers, whereas 76 participants in the experimental group received injections of Type III collagen lyophilized fibers in similar layers. The study analyzed and compared clinical efficacy, WSRS score alterations, patient satisfaction, and safety profiles between the groups over the 30-day and 90-day treatment periods. RESULTS: At the 30-day mark, the therapeutic efficacy was not significantly different between the two groups (P > 0.05). However, at 90 days, the treatment efficacy in the experimental group surpassed that in the control group, showing a statistically significant difference (P < 0.05). After 30 days of treatment, the WSRS score improvement in the experimental group was significantly superior to that in the control group (P < 0.05). Conversely, at the 90-day mark, the results revealed no significant variation in WSRS score improvements between the two groups (P > 0.05). Regarding treatment satisfaction among researchers and participants post-30 and 90-day treatment in both groups, no statistically significant differences were observed (P > 0.05). Similarly, the incidence of adverse reactions between the groups was not statistically significant (P > 0.05). CONCLUSIONS: Injections of lyophilized type III collagen fibers into the mid-to-deep layers of the facial dermis have a definitive therapeutic effect on dynamic facial wrinkles. This treatment not only substantially diminishes wrinkle severity but also has a commendable safety profile. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Platelet-Rich Plasma Versus Platelet-Poor Plasma for Treating Facial Photoaging: a Double-Blind Randomized Controlled Splitting Face Study.

BACKGROUND: As the demand for non-invasive esthetic procedures to maintain a youthful appearance increases, there has been growing interest in the use of autologous platelet-rich plasma (PRP) and platelet-poor plasma (PPP) for the treatment of facial aging. However, there are few studies directly comparing the efficacy of PRP and PPP for facial rejuvenation. OBJECTIVES: This study aimed to compare the efficacy of PRP and PPP for facial rejuvenation. METHODS: This single-center, double-blind, randomized controlled trial was conducted from January 1, 2022, to July 31, 2022, and included ten participants who completed the follow-up. The participants were randomly assigned to receive 2.5-mL injections of PRP and PPP on different sides of the face in three sessions with 1-month intervals. The outcome was primarily determined by blinded photographic assessments and secondly by scores of the VISIA® system during the follow-up. RESULTS: Both PRP and PPP treatments resulted in significant improvement in the Global Aesthetic Improvement Scales and Modified Fitzpatrick Wrinkle Scale for periocular Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation wrinkles, with no significant difference between the two groups. However, no improvement was observed in the Wrinkle Severity Rating Scales for nasolabial folds in either the PRP- or PPP-treated groups. Furthermore, no severe adverse events were reported. CONCLUSIONS: Both PRP and PPP are effective in treating facial photoaging. PRP exhibited slightly superior efficacy in enhancing overall skin condition, while PPP was slightly more effective in improving shallow wrinkles. This study provides valuable evidence for the use of PRP and PPP in facial rejuvenation procedures. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Fabrication of Self-Wrinkling Polymer Films with Tunable Patterns through an Interfacial-Fuming-Induced Surface Instability Process.

Inspired by the superglue fuming method for fingerprint collection, this study developed a novel interfacial-fuming-induced surface instability process to generate wrinkled patterns on polymeric substrates. High-electronegativity groups are introduced on the substrate surface to initiate the polymerization of monomer vapors, such as ethyl cyanoacrylate, which results in the formation of a stiff poly(ethyl cyanoacrylate) capping layer. Moreover, interfacial polymerization resulted in the covalent bonding of the substrate, which led to the volumetric shrinkage of the composite and the accumulation of compressive strain. This process ultimately resulted in the development and stabilization of wrinkled surface morphologies. The authors systematically examined parameters such as the modulus of the epoxy substrate, prestrain, the flow rate of fuming, and operating temperature. The aforementioned technique can be easily applied to architectures with complex outer morphologies and inner surfaces, thereby enabling the construction of surface patterns under ambient conditions without vacuum limitations or precise process control. This study is the first to combine fuming-induced interfacial polymerization with surface instability to create robust wrinkles. The proposed method enables the fabrication of intricate microwrinkled patterns and has considerable potential for use in various practical applications, including microfluidics, optical components, bioinspired adhesive devices, and interfacial engineering.

Advanced Injection of Botulinum Toxin in the Nasal Muscles: A Novel Dynamic Change in Facial Expression.

BACKGROUND: Among the nasal muscles, the levator labii superior alaeque nasi (LLSAN) acts as a transitional muscle that conjugates with other nasal and perinasal muscles. Thus, when treating the nasal region with Botulinum toxin (BTX), it is important to understand local nasal muscular dynamics and how they can influence the muscular dynamics of the entire face. METHODS: This is a retrospective analysis of cases treated by an injection pattern encompassing the face, including nasal muscles. Photographs were taken at rest and during motion (frontal and oblique views), before and after treatment. RESULTS: A total of 227 patients have been treated in the last 18 months with the following results: eyebrow tail lifting, softness of crow's feet, improvement of the drooping of the tip of the nose, and shortening of the lip philtrum when smiling. We present cases illustrating the use of this approach. CONCLUSIONS: Treating the facial muscles globally (including the frontal, corrugators, procerus, orbicularis oculi, platysma, DAO, and nasal muscles) can improve the smile and facial expressions. This is believed to occur because the elevated portion of the upper lip muscle becomes stronger as the nasal part of the LLSAN is paralyzed. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Mechanically Robust and Linearly Sensitive Soft Piezoresistive Pressure Sensor for a Wearable Human-Robot Interaction System.

Soft piezoresistive pressure sensors play an underpinning role in enabling a plethora of future Internet of Things (IoT) applications such as human-robot interaction (HRI) technologies, wearable devices, and metaverse ecosystems. Despite significant attempts to enhance the performance of these sensors, existing sensors still fall short of achieving high strain tolerance and linearity simultaneously. Herein, we present a low-cost, facile, and scalable approach to fabricating a highly strain-tolerant and linearly sensitive soft piezoresistive pressure sensor. Our design utilizes thin nanocracked gold films (NC-GFs) deposited on poly(dimethylsiloxane) (PDMS) as electrodes of the sensor. The large mismatch stress between gold (Au) and PDMS induces the formation of secondary wrinkles along the pyramidal-structured electrode under pressure; these wrinkles function as protuberances on the electrode and enable exceptional linear sensitivity of 4.2 kPa-1 over a wide pressure range. Additionally, our pressure sensor can maintain its performance even after severe mechanical deformations, including repeated stretching up to 30% strain, due to the outstanding strain tolerance of NC-GF. Our sensor's impressive sensing performance and mechanical robustness make it suitable for diverse IoT applications, as demonstrated by its use in wearable pulse monitoring devices and human-robot interaction systems.

Micro-/Nanohierarchical Structures Physically Engineered on Surfaces: Analysis and Perspective.

The high demand for micro-/nanohierarchical structures as components of functional substrates, bioinspired devices, energy-related electronics, and chemical/physical transducers has inspired their in-depth studies and active development of the related fabrication techniques. In particular, significant progress has been achieved in hierarchical structures physically engineered on surfaces, which offer the advantages of wide-range material compatibility, design diversity, and mechanical stability, and numerous unique structures with important niche applications have been developed. This review categorizes the basic components of hierarchical structures physically engineered on surfaces according to function/shape and comprehensively summarizes the related advances, focusing on the fabrication strategies, ways of combining basic components, potential applications, and future research directions. Moreover, the physicochemical properties of hierarchical structures physically engineered on surfaces are compared based on the function of their basic components, which may help to avoid the bottlenecks of conventional single-scale functional substrates. Thus, the present work is expected to provide a useful reference for scientists working on multicomponent functional substrates and inspire further research in this field.