Recently, metasurfaces composed of artificially fabricated subwavelength structures have shown remarkable potential for the manipulation of light with unprecedented functionality. Here, we first ...demonstrate a metasurface application to realize a compact near-eye display system for augmented reality with a wide field of view. A key component is a see-through metalens with an anisotropic response, a high numerical aperture with a large aperture, and broadband characteristics. By virtue of these high-performance features, the metalens can overcome the existing bottleneck imposed by the narrow field of view and bulkiness of current systems, which hinders their usability and further development. Experimental demonstrations with a nanoimprinted large-area see-through metalens are reported, showing full-color imaging with a wide field of view and feasibility of mass production. This work on novel metasurface applications shows great potential for the development of optical display systems for future consumer electronics and computer vision applications.
A multifunctional system comprised of hyaluronic acid microneedles was developed as an effective transdermal delivery platform for rapid local delivery. The microneedles can regulate the filling ...amount on the tip, by controlling the concentration of hyaluronic acid solution. Ultrasonication induces dissolution of the HA microneedles via vibration of acoustic pressure, and AC iontophoresis improves the electrostatic force-driven diffusion of HA ions and rhodamine B. The effect of ultrasound on rhodamine release was analyzed in vitro using a gelatin hydrogel. The frequency and voltage dependence of the AC on the ion induction transfer was also evaluated experimentally. The results showed that the permeability of the material acts as a key material property. The delivery system based on ultrasonication and iontophoresis in microneedles increases permeation, thus resulting in shorter initial delivery time than that required by delivery systems based on passive or ultrasonication alone. This study highlights the significance of the combination between ultrasonic waves and iontophoresis for improving the efficiency of the microneedles, by shortening the reaction duration. We anticipate that this system can be extended to macromolecular and dependence delivery, based on drug response time.
Organic–inorganic hybrid perovskite light‐emitting diodes (PeLEDs) are promising for next‐generation optoelectronic devices due to their potential to achieve high color purity, efficiency, and ...brightness. Although the external quantum efficiency (EQE) of PeLEDs has recently surpassed 20%, various strategies are being pursued to increase EQE further and reduce the EQE gap compared to other LED technologies. A key point to further boost EQE of PeLEDs is linked to the high refractive index of the perovskite emissive layer, leading to optical losses of more than 70% of emitted photons. Here, it is demonstrated that a randomly distributed nanohole array with high‐index contrast can effectively enhance outcoupling efficiency in PeLEDs. Based on a comprehensive optical analysis on the perovskite thin film and outcoupling structure, it is confirmed that the nanohole array effectively distributes light into the substrate for improved outcoupling, allowing for 1.64 times higher light extraction. As a result, highly efficient red/near‐infrared PeLEDs with a peak EQE of 14.6% are demonstrated.
A highly efficient red/near‐infrared perovskite light‐emitting diode (PeLED) with a peak external quantum efficiency of 14.6% is demonstrated using a randomly distributed nanohole array (NHA) with high‐index contrast. The NHA properly compensates the disadvantage of high refractive index of the perovskite emissive layer without altering the PeLED structure, allowing for a 1.64‐times enhanced outcoupling.
Background and Aims The efficacy of palliative biliary drainage by using bilateral or unilateral self-expandable metal stents (SEMSs) for a malignant hilar biliary stricture (MHS) remains ...controversial. This prospective, randomized, multicenter study investigated whether bilateral drainage by using SEMSs is superior to unilateral drainage in patients with inoperable MHSs. Methods Patients with inoperable high-grade MHSs who underwent palliative endoscopic insertion of bilateral or unilateral SEMSs were enrolled. The main outcome measurements were the rate of primary reintervention for malfunction after successful placement of SEMSs, stent patency, technical and clinical success rates, adverse events, and survival duration. Results A total of 133 pathology-diagnosed patients were randomized to the bilateral group (n = 67) or the unilateral group (n = 66). The primary technical success rates were 95.5% (64/67) and 100% (66/66) in the bilateral and unilateral groups, respectively ( P = .244). The clinical success rates were 95.3% (61/64) and 84.9% (56/66), respectively ( P = .047). The primary reintervention rates based on the per-protocol analysis were 42.6% (26/61) in the bilateral group and 60.3% (38/63) in the unilateral group ( P = .049). The median cumulative stent patency duration was 252 days in the bilateral group and 139 days in the unilateral group. The risk of stent patency failure was significantly higher in the unilateral group (log-rank test; P < .01). In a multivariate Cox proportional hazard model to assess stent patency, bilateral SEMS placement was a favorable factor (adjusted hazard ratio 0.30, 95% confidence interval, 0.172-0.521; P < .001). Survival probability and late adverse events were not different between the 2 groups. Conclusions Unilateral and bilateral drainage strategies by using SEMSs had similar technical success rates, but bilateral drainage resulted in fewer reinterventions and more durable stent patency in patients with inoperable high-grade MHSs. (Clinical trial registration number: NCT02166970.)
Recently, addressing various wounds, ranging from skin injuries to pressure and chronic ulcers, has necessitated a more detailed approach to wound condition monitoring aimed at enhancing the ...patient's quality of life. Although most available wound dressings offer protection and promote the regeneration of wound lesions, they fail to monitor wound progression. To meet this need, this study introduces a pioneering solution: a wireless, battery‐free, optoelectronic diagnostic sensor seamlessly integrated into a colorimetric, pH‐sensitive wound dressing, designed to significantly enhance patient quality of life through improved wound care. Curcumin‐polycaprolactone (C‐PCL) dressing protect the wounds, promote cell regeneration, and possess antimicrobial properties. In addition, the dressing exhibits colorimetric pH‐monitoring capabilities across different wound conditions, enabling individuals without specialized knowledge to assess the status of their wounds. The core innovation lies in the integration of a green light‐emitting diode (LED) and photodiode, which meticulously evaluates color changes from yellow to red of colorimetric dressing, enhance the precision of this user‐friendly colorimetric diagnosis strategy. The integration of wireless battery‐free systems facilitates quantitative and real‐time monitoring of wound data in patients without inconvenience. These innovations will pave the way for rapid wound status evaluation, ensuring timely interventions and optimized care for deteriorating wound conditions.
The manuscript introduces an advanced wound care approach: a wireless, battery‐free optoelectronic diagnostic sensor integrated with a colorimetric electrospun nanofiber wound dressing. The innovative strategy employs a Curcumin‐polycaprolactone (C‐PCL) based dressing that changes color in response to pH variations, indicating evolving wound conditions. The integration of an optoelectronic sensor and colorimetric wound dressing for wireless data transmission distinguishes this work.
Hierarchical structures allow one to improve device performance by exploiting the synergistic effects of micro/nano multiscale components. However, the structural complexity of hierarchical ...structures places limits on their fabrication and applications. Herein, a novel morphology-controllable wrinkled micro/nano hierarchical structure (WHS) was developed by integrating micropatterns, nanopatterns, and wrinkles on a single substrate to overcome these limitations. Each structure could be individually controlled, which offers unlimited design diversity. The produced WHS was used as a superhydrophobic triboelectric nanogenerator. Compared to a nanogenerator with on a film structure, the WHS-based nanogenerator showed a superior contact angle of 152.5°, which is indicative of high hydrophobicity, and an enhanced (by 608%) triboelectric effect, which was ascribed to the highly rough surface of the WHS. The WHS-based nanogenerator was used to fabricate a self-powered and water-repellent cough detection sensor with an entirely superhydrophobic structure and stable superior sensing performance during repeated water spraying.
This study describes a novel fabrication method of hierarchical structures, which can integrate micropatterns, nanopatterns, and wrinkles on a single substrate. This method allows one to independently control three different structures and thus fabricate the wrinkled micro/nano hierarchical structures (WHS). The WHS is utilized as a self-powered and water-repellent cough detection sensor that maintains detection performance during repeated water spraying. Display omitted
•A novel fabrication method for wrinkled hierarchical structures (WHSs) is described.•Micropatterns, nanopatterns, and wrinkles can be integrated on a single substrate.•WHSs is utilized as a superhydrophobic triboelectric nanogenerator (S-TENG).•We demonstrate S-TENG as self-powered and water-repellent cough detection sensors.•The sensor maintains superior detection performance during repeated water spraying.
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.
In recent decades, significant progress has been achieved in micro‐/nanohierarchical structures physically engineered on surfaces. This review summarizes the recent advances in the development of such structures, provides a classification of their basic constituents according to function and shape, and discusses the related fabrication strategies, ways of combining basic components, potential applications, and future research directions.
The common behaviour of a wave is determined by wave parameters of its medium, which are generally associated with the characteristic oscillations of its corresponding elementary particles. In the ...context of metamaterials, the decoupled excitation of these fundamental oscillations would provide an ideal platform for top-down and reconfigurable access to the entire constitutive parameter space; however, this has remained as a conceivable problem that must be accomplished, after being pointed out by Pendry. Here by focusing on acoustic metamaterials, we achieve the decoupling of density ρ, modulus B
and bianisotropy ξ, by separating the paths of particle momentum to conform to the characteristic oscillations of each macroscopic wave parameter. Independent access to all octants of wave parameter space (ρ, B
, ξ)=(+/-,+/-,+/-) is thus realized using a single platform that we call an omni meta-atom; as a building block that achieves top-down access to the target properties of metamaterials.
With the advancement of functional textile technology, there is a growing demand for functional enhancements in textiles from both industrial and societal perspectives. Recently, nanopattern transfer ...technology has emerged as a potential approach for fabricating functional textiles. However, conventional transfer methods have some limitations such as transfer difficulties on curved fiber surfaces, polymer residues, and delamination of transferred nanopatterns. In this study, an advanced nanopattern transfer method based on surface modification and thermoforming principles is applied to microscale electrospun fibers. This transfer method utilizes covalent bonding and mechanical interlocking between nanopatterns and the fibers without requiring extra adhesives. Various nanopatterns transferred electrospun fibers possess significant potential for diverse wearable healthcare applications. This work introduces two specific application scenarios in the field of wearable healthcare, both of which leverage the light: diagnostics and antimicrobials. Versatile textile with silver nanogap‐pattern detects glucose in sweat, diagnosing hypoglycemia and diabetes by shifting Raman peaks from 1071.0 to 1075.4 cm−1 for 0 to 150 µm glucose. Additionally, a bactericidal mask using visible light to induce the photocatalytic degradation effect of titanium dioxide and silver nanopatterns is developed. Bactericidal efficacy against Escherichia coli and Staphylococcus aureus is 99.9% due to photolysis from visible light irradiation.
This manuscript presents an innovative nanotransfer printing technique for the functionalization of electrospun textiles. By employing oxygen plasma treatment and a heat pressing, various nanopatterns can be effectively transferred onto electrospun fibers. This study anticipates that such versatile functional textiles will facilitate the diagnosis of glucose levels through the surface‐enhanced Raman scattering method and inhibit bacterial growth through photodegradation.
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