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Heading toward next‐generation intelligent display, dynamic control capability for meta‐devices is critical for real world applications. Beyond the conventional electrical/optical/mechanical/thermal tuning methods, liquid immersion recently has emerged as a facile tuning mechanism which is easily accessible (especially water) and practically implementable for large tuning area. However, due to the longstanding and critical drawback of lacking independent‐encoding capability, the state‐of‐art immersion approach remains incapable of pixel‐level programmable switching. Here a water‐immersion tuning scheme with pixel‐scale programmability for dynamic meta‐displays is proposed. Tunable meta‐pixels can be engineered to construct spectral selective patterns at prior‐/post‐ immersion states, such that a metasurface enables pixel‐level transforming animations for dynamic multifield meta‐displays, including near‐field dual‐nanoprints and far‐field dual‐holographic displays. The proposed water‐immersion programmable approach for meta‐display, benefitting from its large tuning area, facile operation and strong repeatability, may find a revolutionary path toward next‐generation intelligent display with practical applications in dynamic display/encryption, information anticounterfeit/storage, and optical sensors. The proposed water‐immersion programmable meta‐device, for the first time, intriguingly achieves pixel‐programmable water‐immersion switch for multifield meta‐display transformation through screening tunable meta‐pixels to construct spectral programmability, beyond simply coloring alteration, or on‐and‐off switch. The practical water‐immersion mechanism, which enjoys large tuning area, great simplicity in operation and strong repeatability, may find a revolutionary path toward the next‐generation intelligent display technology.

Among the different nanostructures that have been demonstrated as promising materials for various applications, three–dimensional (3D) nanostructures have attracted significant attention as building blocks for constructing high-performance nanodevices because of their unusual mechanical, electrical, thermal, optical, and magnetic properties arising from their novel size effects and abundant active catalytic/reactive sites due to the high specific surface area. Considerable research efforts have been devoted to designing, fabricating, and evaluating 3D nanostructures for applications, including structural composites, electronics, photonics, biomedical engineering, and energy. This review provides an overview of the nanofabrication strategies that have been developed to fabricate 3D functional architectures with exquisite control over their morphology at the nanoscale. The pros and cons of the typical synthetic methods and experimental protocols are reviewed and outlined. Future challenges of fabrication of 3D nanostructured materials are also discussed to further advance current nanoscience and nanotechnology.

Recently, multifunctional metasurface has showcased its powerful functionality to integrate nanoprinting and holography, and display ultracompact meta-images in near- and far-field simultaneously. Herein, we propose a tri-channel metasurface which can further extend the meta-imaging ranges, with three independent images located at the interface, Fresnel and Fourier domains, respectively. Specifically, a structural-color nanoprinting image is decoded right at the interface of the metasurface, enabled by varying the dimensions of nanostructures; a Fresnel holographic image and another Fourier holographic image are present at the Fresnel and Fourier (far-field) domains, respectively, enabled by geometric phase. The spectral and phase manipulation capabilities of nanostructures have been maximized, and the spatial multiplexing capabilities for diffraction in metasurfaces have also been fully exploited. By leveraging the design freedom enabled through the tuning of the geometric size and orientation of nanostructures, as well as optimizing the diffraction spatial light wave transformation, the encoding of multiple images on the single-celled metasurface is achieved. More interestingly, due to the spatial separation of images across different channels, crosstalk is virtually eliminated, effectively enhancing imaging quality. The proposed metasurface offers several advantages, including a compact design, easiness of fabrication, minimal crosstalk, and high storage density. Consequently, it holds promising applications in image display, data storage, information encryption, anti-counterfeiting, and various other fields.

Interference usually occurs between two non-orthogonally polarized light beams. Hence, metasurface enabled polarization multiplexing is generally conducted under two orthogonal polarization states to realize independent intensity and/or phase modulations. Herein, we show that polarization multiplexed metasurfaces can work under three non-orthogonal polarization states to realize tri-channel image displays with independent information encoding. Specifically, enabled by orientation degeneracy, each nanostructure of the metasurface operates with triple-manipulations of light, i.e., two channels for independent intensity manipulation under /4 and 3 /8 linearly polarized (LP) light, respectively, and one channel for phase manipulation without polarization control. We experimentally demonstrate this concept by recording one continuous-brightness polychromatic image and one binary-brightness polychromatic image right at the metasurface plane, while a continuous-brightness polychromatic image is reconstructed in the far field, corresponding to three independent channels, respectively. More interestingly, in another design strategy with separated image encoding of two wavelengths, up to six independent image-display channels can be established and information delivery becomes safer by utilizing encryption algorithms. With the features of high information capacity and high security, the proposed meta-devices can empower advanced research and applications in multi-channel image displays, orbital angular momentum multiplexing communication, information encryption, anti-counterfeiting, multifunctional integrated nano-optoelectronics, etc.

Sensing of viral antigens has become a critical tool in combating infectious diseases. Current sensing techniques have a tradeoff between sensitivity and time of detection; with 10–30 min of detection time at a relatively low sensitivity and 6–12 h of detection at a high (picomolar) sensitivity. In this research, uniquely nanoengineered interfaces are demonstrated on 3D electrodes that enable the detection of spike antigens of SARS‐CoV‐2 and their variants in seconds at femtomolar concentrations with excellent specificity, thus, overcoming this tradeoff. The 3D electrodes, manufactured using a high‐resolution aerosol jet 3D nanoprinter, consist of a microelectrode array of sintered gold nanoparticles coated with graphene and antibodies specific to severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) spike antigens. An impedance‐based sensing modality is employed to sense several pseudoviruses of SARS‐CoV‐2 variants of concern (VOCs). This device is sensitive to most of the pseudoviruses of SARS‐CoV‐2 VOCs. A high sensitivity of 100 fm, along with a low limit‐of‐detection of 9.2 fm within a test range of 0.1–1000 pm, and a detection time of 43 s are shown. This work illustrates that effective nano‐bioengineering of interfaces can be used to create an ultrafast and ultrasensitive healthcare diagnostic tool for combating emerging infections. A 3D microelectrode‐based sensor manufactured by a high‐resolution Aerosol Jet 3D printer serves to detect several pseudoviruses of SARS‐CoV‐2 variants of concern. The high‐performance sensor shows a femtomolar sensitivity with a low limit of detection of 9.2 fm and a detection time of 43 s. This manufacturing modality creates a fast diagnostic tool for combating emerging infections.

3D holographic imaging holds great promise as an immersive display platform, enabling the projection of cubic objects in a specific space and facilitating direct interaction with humans. As 3D holographic imaging continues to evolve, metasurfaces emerge as a promising solution due to their lightweight, compact, and small‐scale properties at the macro level. However, to meet the growing demands for higher information storage, greater freedom in display, and smoother 3D holographic imaging, there is a need for a new metasurface capable of accommodating enhanced 3D holographic abilities by incorporating additional freedom. This paper proposes the use of polarization to add imaging freedom and applies modern gradient descent algorithms to accelerate the design of polarization‐dependent 3D holographic imaging. To enable large‐scale fabrication of the designed metasurfaces and bring polarization‐dependent 3D holographic metasurfaces closer to commercialization, a high‐refractive‐index TiO2 particle‐doped resin‐based large‐scale nanoprinting method is introduced. The design's capabilities are demonstrated by achieving 24 3D holographic images at four polarizations in simulation and ten 3D holographic images in experiment at two polarizations. This work paves the way for the commercialization of multi‐dimensional 3D holographic imaging based on metasurfaces, ushering in a new era of compact, lightweight, and large‐scale multi‐dimensional 3D holographic displays. A novel polarization‐dependent 3D holography is proposed by introducing polarization as an additional freedom, enabling enhanced depth selectivity and greater control over holographic reconstruction. The efforts perfectly combine the polarization and 3D holography display into ADAM gradient descent algorithm, the application of nanoprinting further makes the polarization‐dependent 3D holography metasurface functional.

Gas-assisted focused electron beam-induced deposition (FEBID) as a direct, minimally invasive 3D nanopatterning tool offers many advantages in making nanostructures with complex shapes and novel compositions for evolving nanotechnological applications. In this work, structures were nanoprinted using a fluorine-free β-ketoesterate complex, bis( tert -butylacetoacetate)palladium(II), [Pd(tbaoac) 2 ]. The internal nanostructure and composition of the deposits were determined, and possible volatile products produced under electron-induced dissociation, explaining the composition, are investigated. A method to eliminate the residual gas contamination during FEBID was implemented. [Pd(tbaoac) 2 ] contains large organic ligands and only about 5 atom % palladium in the pristine molecule, yet the obtained palladium content in the deposits amounts to around 30 atom %. This translates to an exceptional removal efficiency of about 90% for the ligand-constituting elements carbon and oxygen through electron-induced dissociation and desorption mechanisms. Comparison with other precursors confirms that the β-ketoesterate family has the highest ligand removal percentage and constitutes thus an interesting model chemistry for further high-metal-content FEBID studies. The possibility of growing nanopillars makes this complex a promising precursor for nanoprinting 3D structures with finely focused electron beams.

The systems for multiphoton 3D nanoprinting are rapidly increasing in print speed for larger throughput and scale, unfortunately without also improvement in resolution. Separately, the process of photoinhibition lithography has been demonstrated to enhance the resolution of multiphoton printing through the introduction of a secondary laser source. The photo-chemical dynamics and interactions for achieving photoinhibition in the various multiphoton photoinitiator systems are complex and still not well understood. Here, we examine the photoinhibition process of the common photoinitiator 7-diethylamino 3-thenoylcoumarin (DETC) with inhibition lasers near or at the multiphoton printing laser wavelength in typical low peak intensity, high repetition rate 3D nanoprinting processes. We demonstrate the clear inhibition of the polymerization process consistent with a triplet absorption deactivation mechanism for a DETC photoresist as well as show inhibition for several other photoresist systems. Additionally, we explore options to recover the photoinhibition process when printing with high intensity, low repetition rate lasers. Finally, we demonstrate photoinhibition in a projection multiphoton printing system. This investigation of photoinhibition lithography with common photoinitiators elucidates the possibility for photoinhibition occurring in many resist systems with typical high repetition rate multiphoton printing lasers as well as for high-speed projection multiphoton printing.

Piezoceramic is ubiquitously used in high-performance sensors and actuators. Three-dimensional (3D) printing of lead zirconate titanate (PZT) is attractive and highly desired for such device applications, but most of the existing methods are inherently limited to micron resolution, which makes them untenable for fabricating complex 3D architectures with high-definition features. Here, an electrohydrodynamic jet (E-Jet) nanoprinting strategy has been proposed to fabricate PZT 3D structures with the characteristics of flexibility and scalability. Different kinds of 3D PZT true nanostructures (resolution ∼40 nm, aspect ratio ∼400) were directly fabricated using a 100 μm-sized nozzle. And the PZT nanostructures exhibited well-developed perovskite crystal morphology, large elastic strain (elongation ≈ 13%), and high piezoelectric property (d 31 ≈ (236.5 × 10 −12 ) C·N −1 ). A bionic PZT air-flow sensor was printed to monitor air-flow detection, demonstrating well sensitivity with ultra-slow air-flow of 0.02 m·s −1 . The discovery reveals an efficient pathway to 3D-printing PZT nanostructures for next-generation high-performance piezoelectric devices. A 3D nanoprinting piezoceramic method was proposed. Various PZT nanostructures were directly printed under controllability and scalability. The printed nanostructure exhibited excellent performance. A new strategy for the next-generation nanoscale additive manufacturing was provided.

The concept and feasibility of producing liposomes by rehydrating engineered lipid nanoconstructs are demonstrated in this study. Nanoconstructs of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were produced using a microfluidic delivery probe integrated with an atomic force microscope. The subsequent rehydration of these POPC constructs led to the formation of liposomes, most of which remained adhered to the surface. The size (e.g., diameter) of the liposomes could be tuned by varying the lateral dimension of the lipid constructs. Hierarchical liposomal structures, such as pentagons containing five liposomes at the corners, could also be designed and produced by depositing lipid constructs to designated locations on the surfaces, followed by rehydration. This new means allows for regulating liposomal sizes, distributions, and compositions. The outcomes benefit applications of liposomes as delivery vehicles, sensors, and building blocks in biomaterials design. The ability to produce hierarchical liposomal structures benefits numerous applications such as proto-cell development, multiplexed bio-composite materials, and the engineering of local bio-environments.