Synergistic Multimodal Energy Dissipation Enhances Certified Efficiency of Flexible Organic Photovoltaics beyond 19.

All-polymer organic solar cells (OSCs) have shown unparalleled application potential in the field of flexible wearable electronics in recent years due to the excellent mechanical and photovoltaic properties. However, the small molecule acceptors after polymerization in still retain some mechanical and aggregation properties of the small molecule, falling short of the ductility requirements for flexible devices. Here, based on the multimodal energy dissipation theory, the mechanical and photovoltaic properties of flexible devices are co-enhanced by adding the thermoplastic elastomer material (polyurethane, PU) to the PM6:PBQx-TF:PY-IT-based active layer films.

3D Optical Heterostructure Patterning by Spatially Allocating Nanoblocks on a Printed Matrix.

Heterostructures have attracted enormous interest due to the properties arising from the coupling and synergizing between multiscale structures and the promising applications in electronics, mechanics, and optics. However, it is challenging for current technologies to precisely integrate cross-scale micro/nanomaterials in three dimensions (3D). Herein, we realize the precise spatial allocation of nanoblocks on micromatrices and programmable 3D optical heterostructure patterning via printing-assisted self-assembly.

A Direct Writing Approach for Organic Semiconductor Single-Crystal Patterns with Unique Orientation.

Organic semiconductor single-crystal (OSSC) patterns with precisely controlled orientation are of great significance to the integrated fabrication of devices with high and uniform performance. However, it is still challenging to achieve purely oriented OSSC patterns due to the complex nucleation and growth process of OSSCs. Here, a general direct writing approach is presented to readily obtain high-quality OSSC patterns with unique orientation.

Implementing Contact Angle Hysteresis in Moving Mesh-Based Two-Phase Flow Numerical Simulations.

Contact angle hysteresis is a common phenomenon in nature, which also plays an important role in industrial applications. A numerical model based on the moving mesh two-phase flow method is presented for modeling contact angle hysteresis. The implementation includes a displacement-based penalty method and a state variable method.

Marangoni Flow Manipulated Concentric Assembly of Cellulose Nanocrystals.

Tunable assembly of cellulose nanocrystals (CNCs) is important for a variety of emerging applications in optics, sensing, and security. Most exploited assembly and optical property of CNCs are cholesteric assembly and corresponding circular dichroism. However, it still remains challenge to obtain homogenous and high-resolution cholesteric assembly.

Skin-Driven Ultrasensitive Mechanoluminescence Sensor Inspired by Spider Leg Joint Slits.

Inspired by the spider's slit organ embedded in the leg joint exoskeleton and its ultrasensitive stress perception, we propose to fix the conflict between the stress concentration requirement for bright mechanoluminescence (ML) and the stress dispersion effect of soft material via integrating slit microstructures into flexible films. The designed slits focus weak stresses onto the corner to achieve high sensitivity, leading to 10-30 times ML intensity improvement at weak strain (<10% stretch) application. Slit morphology and various patterns were well investigated to address the stress distribution regularity.

Breaking the symmetry to suppress the Plateau-Rayleigh instability and optimize hydropower utilization.

Droplet impact on solid surfaces is essential for natural and industrial processes. Particularly, controlling the instability after droplet impact, and avoiding the satellite drops generation, have aroused great interest for its significance in inkjet printing, pesticide spraying, and hydroelectric power collection. Herein, we found that breaking the symmetry of the droplet impact dynamics using patterned-wettability surfaces can suppress the Plateau-Rayleigh instability during the droplet rebounding and improve the energy collection efficiency.

Lotus Metasurface for Wide-Angle Intermediate-Frequency Water-Air Acoustic Transmission.

Only 0.1% of the acoustic energy can transmit across the water-air interface because of the huge acoustic impedance mismatch. Enhancing acoustic transmission across the water-air interface is of great significance for sonar communications and sensing.

Tunable Fluid-Type Metasurface for Wide-Angle and Multifrequency Water-Air Acoustic Transmission.

Efficient acoustic communication across the water-air interface remains a great challenge owing to the extreme acoustic impedance mismatch. Few present acoustic metamaterials can be constructed on the free air-water interface for enhancing the acoustic transmission because of the interface instability. Previous strategies overcoming this difficulty were limited in practical usage, as well as the wide-angle and multifrequency acoustic transmission.

Magnetic-actuated "capillary container" for versatile three-dimensional fluid interface manipulation.

Fluid interfaces are omnipresent in nature. Engineering the fluid interface is essential to study interfacial processes for basic research and industrial applications. However, it remains challenging to precisely control the fluid interface because of its fluidity and instability.

3D Printing a Biomimetic Bridge-Arch Solar Evaporator for Eliminating Salt Accumulation with Desalination and Agricultural Applications.

Solar-driven water evaporation has been considered a sustainable method to obtain clean water through desalination. However, its further application is limited by the complicated preparation strategy, poor salt rejection, and durability. Herein, inspired by superfast water transportation of the Nepenthes alata peristome surface and continuous bridge-arch design in architecture, a biomimetic 3D bridge-arch solar evaporator is proposed to induce Marangoni flow for long-term salt rejection.

Vapor-Induced Liquid Collection and Microfluidics on Superlyophilic Substrates.

Liquid manipulation on solid surfaces has attracted a lot of attention for liquid collection and droplet-based microfluidics. However, manipulation strategies mainly depend on chemical modification and artificial structures. Here, we demonstrate a feasible and general strategy based on the self-shrinkage of the droplet induced via specific vapors to efficiently collect liquids and flexibly carry out droplet-based reactions.

Evaporation Induced Spontaneous Micro-Vortexes through Engineering of the Marangoni Flow.

Vortex flow fields are widely used to manipulate objects at the microscale in microfluidics. Previous approaches to produce the vortex flow field mainly focused on inertia flows. It remains a challenge to create vortexes in Stokes flow regime.

Recognition and location of motile microorganisms by shape-matching photoluminescence micropatterns.

The typical dimensions of bacterial and microorganism cells match well with the scales at which nanomaterial-based architectures can influence the environment. However, it is one of the most formidable challenges to achieve designed patterns at the microscale for studying microorganisms. Here, we present a method to recognize and locate motile microorganisms at the microscale.

Bio-inspired vertebral design for scalable and flexible perovskite solar cells.

The translation of unparalleled efficiency from the lab-scale devices to practical-scale flexible modules affords a huge performance loss for flexible perovskite solar cells (PSCs). The degradation is attributed to the brittleness and discrepancy of perovskite crystal growth upon different substrates. Inspired by robust crystallization and flexible structure of vertebrae, herein, we employ a conductive and glued polymer between indium tin oxide and perovskite layers, which simultaneously facilitates oriented crystallization of perovskite and sticks the devices.

Non-Lithography Hydrodynamic Printing of Micro/Nanostructures on Curved Surfaces.

A key issue of micro/nano devices is how to integrate micro/nanostructures with specified chemical components onto various curved surfaces. Hydrodynamic printing of micro/nanostructures on three-dimensional curved surfaces is achieved with a strategy that combines template-induced hydrodynamic printing and self-assembly of nanoparticles (NPs). Non-lithography flexible wall-shaped templates are replicated with microscale features by dicing a trench-shaped silicon wafer.

Controllable Growth of High-Quality Inorganic Perovskite Microplate Arrays for Functional Optoelectronics.

Inorganic perovskite single crystals have emerged as promising vapor-phase processable structures for optoelectronic devices. However, because of material lattice mismatch and uncontrolled nucleation, vapor-phase methods have been restricted to random distribution of single crystals that are difficult to perform for integrated device arrays. Herein, an effective strategy to control the vapor-phase growth of high-quality cesium lead bromide perovskite (CsPbBr ) microplate arrays with uniform morphology as well as controlled location and size is reported.

Omnidirectional Photodetectors Based on Spatial Resonance Asymmetric Facade via a 3D Self-Standing Strategy.

Integration of photovoltaic materials directly into 3D light-matter resonance architectures can extend their functionality beyond traditional optoelectronics. Semiconductor structures at subwavelength scale naturally possess optical resonances, which provides the possibility to manipulate light-matter interactions. In this work, a structure and function integrated printing method to remodel 2D film to 3D self-standing facade between predesigned gold electrodes, realizing the advancement of structure and function from 2D to 3D, is demonstrated.

Bioinspired Patterned Bubbles for Broad and Low-Frequency Acoustic Blocking.

Bubble crystals in water are expected to achieve the broad and low-frequency acoustic band gaps that are crucial for acoustic blocking. However, preparing patterned bubble crystals in water remains a challenge because of the instability of bubbly liquids. Here, inspired by biological superhydrophobic systems, we report a simple and rapid approach to prepare patterned bubble arrays in water and their applications in low-frequency acoustic blocking.

Fully Printed Geranium-Inspired Encapsulated Arrays for Quantitative Odor Releasing.

Olfactory is an extremely fine way of perception. However, the process of smelling is prone to various interference factors. Further development to enhance the communication desires an odor-releasing strategy, which could quantitatively offer a variety of fragrances.

Heterogeneous Integration of Three-Primary-Color Photoluminescent Nanoparticle Arrays with Defined Interfaces.

Minimized photoluminescent devices require both high-density fluorescent arrays and minimal cross-talk between neighboring pixels on the limited area. However, the challenges to achieve the overall integration of nanomaterial-based devices hinder the development of microscale full-color displays, including micro/nanoarray density, orientation control, multimaterial interface morphology, and uniform colors. Here, we report a heterogeneous integration approach to control the orientation, combination, and density of fluorescent micro/nanoarrays on flexible substrates.

Patterning Bubbles by the Stick-Slip Motion of the Advancing Triple Phase Line on Nanostructures.

The stick-slip motion of the triple phase contact line (TCL) has wide applications in inkjet printing, surface coatings, functional material assembly, and device fabrication. Here, for the first time, we report that on an alumina substrate with nanostructures, the stick-slip motion of the advancing TCL during spreading of an emulsion droplet can serve as an effective nanopatterning process. Air enclosed in the substrate nanostructures can be exchanged with liquid during the "stick" phase, resulting in the formation of bubbles arranged in a ring pattern.

Printable Skin-Driven Mechanoluminescence Devices via Nanodoped Matrix Modification.

Mechanically driven light generation is an exciting and under-exploited phenomenon with a variety of possible practical applications. However, the current driving mode of mechanoluminescence (ML) devices needs strong stimuli. Here, a flexible sensitive ML device via nanodopant elasticity modulus modification is introduced.