Nano Printing Research Articles

Free-standing microscale photonic lantern spatial mode (De-)multiplexer fabricated using 3D nanoprinting

Photonic lantern (PL) spatial multiplexers show great promise for a range of applications, such as future high-capacity mode division multiplexing (MDM) optical communication networks and free-space optical communication. They enable efficient conversion between multiple single-mode (SM) sources and a multimode (MM) waveguide of the same dimension. PL multiplexers operate by facilitating adiabatic transitions between the SM arrayed space and the single MM space. However, current fabrication methods are forcing the size of these devices to multi-millimeters, making integration with micro-scale photonic systems quite challenging. The advent of 3D micro and nano printing techniques enables the fabrication of freestanding photonic structures with a high refractive index contrast (photopolymer-air). In this work we present the design, fabrication, and characterization of a 6-mode mixing, 375 µm long PL that enables the conversion between six single-mode inputs and a single six-mode waveguide. The PL was designed using a genetic algorithm based inverse design approach and fabricated directly on a 7-core fiber using a commercial two-photon polymerization-based 3D printer and a photopolymer. Although the waveguides exhibit high index contrast, low insertion loss (−2.6 dB), polarization dependent (−0.2 dB) and mode dependent loss (−4.4 dB) were measured.

Mechanism and influencing factors analysis of polyethylene oxide electrohydrodynamic printing

AbstractElectrohydrodynamic (EHD) printing is a micro–nano printing technology based on the principles of electric field and fluid dynamics. It is characterized by high resolution, high precision, and high speed, applied to various materials, including metals, ceramics, and organic materials. Compared with traditional printing technologies, EHD printing offers advantages such as low manufacturing cost, simple process, and direct fabrication, making it highly promising in the field of micro–nano manufacturing. Polyethylene oxide (PEO) is a highly water‐soluble polymer that has been widely used in various fields due to its low toxicity and ease of processing. In this study, a finite element simulation model was developed using simulation software to simulate and analyze the mechanisms of focused jetting and deposition of PEO solution under an electric field. Based on the principles of electrohydrodynamics, a self‐built EHD printing system was used to investigate the influence of different solution mass fractions and printing parameters on fiber formation, and the optimal process window of EHD printing PEO solution was obtained. Ultimately, ordered deposition of fiber lines ranging from 1.761 to 6.093 μm was achieved. The simulation results were consistent with the experimental results, validating the effectiveness of the established model in guiding jetting outcomes.Highlights Independently building a low‐cost electrohydrodynamic (EHD) printing system. Finite element simulation of EHD printing process. Mechanism analysis of PEO solution jetting and deposition. Optimal process window for PEO solution EHD printing. Influence of key process parameters on fiber forming width.

Nozzle-based precision patterning with micro-/nano fluidics integrated cantilevers

As the requirements of micro-/nano printing technologies are continuously increasing, direct writing technologies on a submicron scale are drawing attention. One of the promising methods is a nozzle-based precision patterning with atomic force microscopy (AFM), which has the advantages of high position controllability including nozzle-to-substrate distance feedback under a nanometer scale. It uses a fluidic channel and a dispensing nozzle integrated with a cantilever structure for deflection monitoring. In this paper, we introduce micro/nanofluidics integrated cantilevers for nozzle-based precision patterning in several considerations: 1) numerous fabrication strategies for nozzle-integrated fluidic cantilevers; 2) methods for liquid transport; 3) methods for pattern formation; and 4) applications with various printing materials.

Advanced fiber in-coupling through nanoprinted axially symmetric structures

Here, we introduce and demonstrate nanoprinted all-dielectric nanostructures located on fiber end faces as a novel concept for the efficient coupling of light into optical fibers, especially at multiple incidence angles and across large angular intervals. Taking advantage of the unique properties of the nanoprinting technology, such as flexibly varying the width, height, and gap distance of each individual element, we realize different polymeric axial-symmetric structures, such as double-pitch gratings and aperiodic arrays, placed on the facet of commercial step-index fibers. Of particular note is the aperiodic geometry, enabling an unprecedentedly high average coupling efficiency across the entire angular range up to 80°, outperforming regular gratings and especially bare fibers by orders of magnitude. The excellent agreement between simulation and experiment clearly demonstrates the quality of the fabricated structures and the high accuracy of the nanoprinting process. Our approach enables realizing highly integrated and ready-to-use fiber devices, defining a new class of compact, flexible, and practically relevant all-fiber devices beyond the state-of-art. Applications can be found in a variety of cutting-edge fields that require highly efficient light collection over selected angular intervals, such as endoscopy or quantum technologies. Furthermore, fiber functionalization through nanoprinting represents a promising approach for interfacing highly complex functional photonic structures with optical fibers.

Separated nano jetting and micro jetting regimes by double-pulse irradiation of a metal film: towards multiscale printing.

The Double-Pulse (DP) version of the Laser-Induced Forward Transfer (LIFT) technique holds great potential to improve the resolution and flexibility of printing applications. In this study, we investigate the transfer of copper. A long laser pulse is first applied to melt thin copper films deposited on a transparent substrate, followed by an ultrashort laser pulse to initiate the transfer of the liquid material towards a receiver substrate. Time-resolved imaging experiments reveal that ejections from nanodrops to liquid jets with controllable diameters, from few micrometers down to the nanometers scale can be obtained with the control parameters of DP-LIFT. Comparing simulation and experiments we discuss how the ejection characteristics are governed by various factors including the shape, diameter and temperature of the melted pool created with the first long pulse. While the formation of microjets is due to the dynamical deformation of the melted film, as for the conventional LIFT process applied with liquid donors, the results indicate a different and distinct process for the formation of nanojets. We extrapolate from the observations a feature caused by the interaction of the shockwave, generated by the femtosecond laser irradiation, with the deformed surface of the pool. Ultimately, we establish the range of irradiation parameters leading to the observation of single separated microjets and nanojets. The latter are accompanied by nano printing demonstrations. Considering all accessible regimes together, a unique technological perspective is the possibility to achieve multi-scale printing from the same donor.

3D printing of nanowrinkled architectures via laser direct assembly.

Structural wrinkles in nature have been widely imitated to enhance the surface functionalities of objects, especially three-dimensional (3D) architectured wrinkles, holding promise for emerging applications in mechanical, electrical, and biological processes. However, the fabrication of user-defined 3D nanowrinkled architectures is a long-pending challenge. Here, we propose a bottom-up laser direct assembly strategy to fabricate multidimensional nanowrinkled architectures in a single-material one-step process. Through the introduction of laser-induced thermal transition into a 3D nanoprinting process for leading the point-by-point nanoscale wrinkling and the self-organization of wrinkle structures, we have demonstrated the program-controlled and on-demand fabrication of multidimensional nanowrinkled structures. Moreover, the precise control of wrinkle morphology with an optimal wavelength of 40 nanometers and the regulation of the dynamic transformation of wrinkled cellular microstructures via interfacial stress mismatch engineering have been achieved. This study provides a universal protocol for constructing nearly arbitrary nanowrinkled architectures and facilitates a new paradigm in nanostructure manufacturing.

High Precision 3D Printing for Micro to Nano Scale Biomedical and Electronic Devices.

Three dimensional printing (3DP), or additive manufacturing, is an exponentially growing process in the fabrication of various technologies with applications in sectors such as electronics, biomedical, pharmaceutical and tissue engineering. Micro and nano scale printing is encouraging the innovation of the aforementioned sectors, due to the ability to control design, material and chemical properties at a highly precise level, which is advantageous in creating a high surface area to volume ratio and altering the overall products’ mechanical and physical properties. In this review, micro/-nano printing technology, mainly related to lithography, inkjet and electrohydrodynamic (EHD) printing and their biomedical and electronic applications will be discussed. The current limitations to micro/-nano printing methods will be examined, covering the difficulty in achieving controlled structures at the miniscule micro and nano scale required for specific applications.

Low-reflective wire-grid polariser sheet in the visible region fabricated by a nanoprinting process

For the construction of next-generation optical products and systems, the evolution of polariser sheets is a necessary requirement. To this end, a low-reflective wire-grid polariser (WGP) sheet for the visible light region is demonstrated, the nanowires of which consist of a sintered body of silver nanoparticle ink. The nanowires are formed by a nanoprinting process using a thermal nanoimprint method and ink filling. This process makes it easier to achieve multiple wafer-scale productions without using sophisticated equipment compared to conventional WGP nanofabrication techniques, which typically employ lithography and elaborate etching processes. The optical characteristics are controlled by the shape of the printed nanowires. A WGP sheet with a luminous degree of polarisation of 99.0%, a total luminous transmittance of 13.6%, and a luminous reflectance of 3.6% is produced. Its low reflectance is achieved through the uneven surface derived from the sintered body of the nanoparticle ink, and the shape of the bottom of the nanowire is derived from the tip shape of the mould structure. Furthermore, the printed WGP sheet has the durability required for the manufacturing of curved products, including sunglasses. The optical structures made of nanoparticle ink using this nanoprinting process have the potential to significantly contribute to the development of fine-structured optical elements with unprecedented functionality.

Cyber coordinated simulation for distributed multi-stage additive manufacturing systems

Additive Manufacturing (AM) processes have been increasingly used to manufacture energy storage products with dedicated material preparation and post-processing stages to enhance product properties. Most researchers focus on selecting materials and improving processes, yet the system modeling and management has not been investigated so far. This paper extends the conventional single-stage AM processes to multi-STage distRibutEd AM (STREAM) systems. In STREAM, a batch of material produced at the pre-processing stage is jointly consumed by distributed AM printers, and then the printed parts are collected for the post-processing stage. Modeling and managing such complex systems have been challenging. We propose a novel framework for “cyber-coordinated simulation” to manage the hierarchical information in STREAM. This is important because simulation can be used to infuse data into predictive analytics, thus providing guidance for the optimization and control of STREAM operations. The proposed framework is hierarchical in nature, where the single-stage, multi-stage, and distributed productions are modeled through the integration of different simulators. We demonstrate the proposed framework with simulation data from Freeze Nano Printing (FNP) AM for the fabrication of energy storage products.

Present status of the functional advanced micro-, nano-printings – a mini review

Additive printing technology and expertise have experienced noteworthy development driven by their ability to revolutionize academic and industrial manufacturing and research. They also have particular practical uses in the areas of micro and nanofabrication. Micro- and nano-printings have found a tremendous number of applications in material synthesis/patterning, electronics, medicine and biotechnology. In this mini review, we examine the important additive micro and nano printing techniques, including contact and noncontact, and roll to roll (R2R) printing methods as well as recently emerging techniques such as micro- or nano-pen printings, laser-induced forward transfer (LIFT) and aerosol jet printing (APJ). We also discuss the materials that are printable by these technologies, the applications of micro- and nano-printings, key features, advantages and challenges.

Parallel, Multi-Material Electrohydrodynamic 3D Nanoprinting.

Direct mass-transfer via liquid nanodroplets is one of the most powerful approaches for additive micro/nanofabrication. Electrohydrodynamic (EHD) dispensing has made the delivery of nanosized droplets containing diverse materials a practical reality; however, in its serial form it has insufficient throughput for large-area processing. Here, a parallel, nanoscale EHD method is developed that offers both improved productivity and material diversity in 3D nanoprinting. The method exploits a double-barreled glass nanopipette filled with material inks to parallelize nanodripping ejections, enabling a dual 3D nanoprinting process. It is discovered that an unusual electric field distribution created by cross talk of neighboring pipette apertures can be used to steer the microscopic ejection paths of the ink at will, enabling on-demand control over shape, placement, and material mixing in 3D printed nanostructures. After thorough characterizations of the printing conditions, the parallel fabrication of nanomeshes and nanowalls of silver, CdSe/ZnS quantum dots, and their composites, with programmed designs is demonstrated. This method is expected to advance productivity in the heterogeneous integration of functional 3D nanodevices in a facile manner.

Nearest Neighbor Gaussian Process Emulation for Multi-Dimensional Array Responses in Freeze Nano 3D Printing of Energy Devices

Abstract Energy 3D printing processes have enabled the manufacturing of energy storage devices with complex structures, high energy density, and high power density. Among these processes, freeze nano printing (FNP) has risen as a promising process. However, quality problems are among the biggest barriers for FNP and other 3D printing processes. Particularly, the droplet solidification time in FNP governs the thermal distribution and subsequently determines the product solidification, formation, and quality. To describe the solidification time, a physical-based heat transfer model is built. But, it is computationally intensive. The objective of this work is to build an efficient emulator for the physical model. There are several challenges unaddressed before: (1) the solidification time at various locations, which is a multi-dimensional array response, needs to be modeled and (2) the construction and evaluation of the emulator at new process settings need to be quick and accurate. Here, we integrate joint tensor decomposition and nearest neighbor Gaussian process (NNGP) to construct an efficient multi-dimensional array response emulator with process settings as inputs. Specifically, structured joint tensor decomposition decomposes the multi-dimensional array responses at various process settings into the setting-specific core tensors and shared low-dimensional factorization matrices. Then, each independent entry of the core tensor is modeled with an NNGP, which addresses the computationally intensive model estimation problem by sampling the nearest neighborhood samples. Finally, tensor reconstruction is performed to make predictions of the solidification time for new process settings. The proposed framework is demonstrated by emulating the physical model of FNP and compared with alternative tensor (multi-dimensional array) regression models.

Construction of Sensitive Surface‐Enhanced Raman Spectroscopy Chip with Sub‐Nanometer WO3−x Nanowire‐Based Superstructures for Multicomponent Detection

AbstractExploring nonmetallic plasmonic materials is desirable yet challenging. For a long time, free‐plasmonic semiconductor is difficult to be used in high‐sensitive surface‐enhanced Raman spectrum (SERS) due to poor enhanced factor and high‐fluorescent background. Herein, it is reported that a nonmetallic plasmonic SERS chip, constructed with a highly ordered sub 1 nm WO3−x nanowire‐based superstructure, shows multicomponent detection capability. The densely arranged nanowires enable a strong localized surface plasmon resonance due to the high charge carriers' density induced by oxygen vacancies in the nanowires. In addition to the usual charge‐transfer enhancement, such nonmetallic WO3−x displays a unusual dramatic plasmon‐enhanced SERS sensing performance with a detection limit of 10−10 m and a maximum Raman enhanced factor of 8.3 × 107. The substrate fluorescence signals are efficiently quenched, making the SERS spectra more distinguishable. More importantly, the prepared WO3−x SERS chip through micro–nano printing realizes the separation and detection of multicomponents simultaneously.

Fabrication of Scaffold-Based 3D Magnetic Nanowires for Domain Wall Applications.

Three-dimensional magnetic nanostructures hold great potential to revolutionize information technologies and to enable the study of novel physical phenomena. In this work, we describe a hybrid nanofabrication process combining bottom-up 3D nano-printing and top-down thin film deposition, which leads to the fabrication of complex magnetic nanostructures suitable for the study of new 3D magnetic effects. First, a non-magnetic 3D scaffold is nano-printed using Focused Electron Beam Induced Deposition; then a thin film magnetic material is thermally evaporated onto the scaffold, leading to a functional 3D magnetic nanostructure. Scaffold geometries are extended beyond recently developed single-segment geometries by introducing a dual-pitch patterning strategy. Additionally, by tilting the substrate during growth, low-angle segments can be patterned, circumventing a major limitation of this nano-printing process; this is demonstrated by the fabrication of ‘staircase’ nanostructures with segments parallel to the substrate. The suitability of nano-printed scaffolds to support thermally evaporated thin films is discussed, outlining the importance of including supporting pillars to prevent deformation during the evaporation process. Employing this set of methods, a set of nanostructures tailored to precisely match a dark-field magneto-optical magnetometer have been fabricated and characterized. This work demonstrates the versatility of this hybrid technique and the interesting magnetic properties of the nanostructures produced, opening a promising route for the development of new 3D devices for applications and fundamental studies.

나노기술을 활용한 나노아트의 창의융합 연구

Nano art is a representative artistic expression upon which a transition to art using nano technology is reflected. Nano art, based on its nano technology and creative convergence, has been applied to diverse future industries of the 21st century, and its expectancy effects are significant.BR Nano art is a newly created result of the integration between innovative influences and artistic influences. As far as nano art is concerned, Richard P. Feynman, a Nobel Prize Winner in Physics, and various scientists such as K. Eric Drexler, Eduardo Kac, and Cris Orfescu conducted an artistic experiment in the nano world, and as imaging technology capable of replicating the nano world made progress in the 1980’s, nano art has become a genre.BR The purpose of this research was to analyze the precedent researches, theoretical considerations, statuses and research trends and detailed cases required to conduct a research on creative convergence of nano art using nano technology, and, thereby, suggest a directions for future progress.BR The research content and method were as follows.BR Phase 1: To theoretically consider the definitions, concepts, characteristics, fields, progress and future, and precedent researches through understanding nano technology and nano art as a concept emphasizing creative convergence. Phase 2: To understand and analyze the trends and detailed cases of creative convergence of nano art. Phase 3: To suggest a direction for future progress based on the results acquired through theoretically considering nano technology and nano art, and through analyzing the trends and detailed cases of creative convergence of nano art.BR The results of this research were as follows.BR Initially, the researches on creative convergence of nano art using nano technology have been using diverse techniques to explore diverse forms of the extremely microscopic world, phenomena, issues and values not only inside the laboratory, but also outside the laboratory through a state-of-the-art nano microscope. Secondly, although the researches on creative convergence of nano art using nano technology deal with the extremely microscopic world, phenomena, issues and values, due to its enormous influence and ripple effect, it is an innovative future-oriented field that essentially requires a new concept of imagination. Thirdly, the exhibitions involving creative convergence of nano art are particular in that they are experiential, intellective exhibitions emphasizing the combination between art and science technology, the cultural convergence between nano science and nano technology, and the visual tactility based on the touch of an electron microscope.BR The conclusion and suggestion of this research were as follows. Initially, the researches on creative convergence of nano art using nano technology should serve as an expression of the technological revolution seeking a better future where the future 4th industries such as robot engineering, artificial intelligence, virtual reality and augmented reality are connected. Secondly, the researches on creative convergence of nano art using nano technology should serve as part of the work process and education system connected to the future 4th industries, and it is necessary to develop an education program and establish a research environment for that purpose. Thirdly, although the researches on creative convergence of nano art using nano technology are actively conducted in various fields such as nano antibiotic technology, nano clothing products, skiing products, lotus effect automobiles, 3D nano printing, nano wine and nano architecture, since such researches are limited to the fields of fine art and building industry in Korea, it is necessary for the interested parties to make efforts for improvements, and for the government to provide its political support.

Efficient fabrication of poly(pyrrole)-nanowires through innovative nanocontact printing, using commercial CD as mold, on flexible thermoplastics substrates: Application for cytokines immunodetection

Abstract Poly(pyrrole)-nanowires (PPy-NWs) were efficiently printed by using nano printing on flexible thermoplastics, and then used to device an impedimetric immunosensor. The present pioneering technology allow to create high sensitive and disponsable immunosensor devised using a low cost and simple fabrication. The innovative nanocontact printing uses a PDMS stamp replicated from a CD mold. The PPyNW printing uses controlled chemical polymerization to print PPy-NWs on poly (ethylene terephthalate) and polyether ether ketone surfaces. Atomic force microscopy analysis of PPyNW revealed a width, height and a separation length of 125 ± 8 nm, 377 ± 5 nm and 172 ± 4 nm, respectively. The PPy-NWs were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The XPS results evidenced the covalent bonding between the thermoplastic surface and the PPyNWs. As a final point, the immunosensor was tested for the quantification of Interleukin 6 recombinant human (IL6, Ag) using EIS. The PPy-NWs were functionalized via diazonium coupling reaction and carbodiimide crosslinker chemistry for the immobilization of Anti-human IL-6 monoclonal antibodies (IL6 mAb’s). The developed immunosensor exhibited a sensitivity of 0.013 (pg/mL) −1 (linear fitting at R 2 = 0.99) and limit of detection (LOD) of 0.36 pg/mL in a linear range of 1–50 pg/mL for Ag IL-6, with a relative standard deviation percentage (RSD%) at 7.6%.

Parameter Study of Three-Dimensional Printing Graphene Oxide Based on Directional Freezing

Graphene is one of the most promising carbon nanomaterial due to its excellent electrical, thermal, optical, and mechanical properties. However, it is still very challenging to unlock its exotic properties and widely adopt it in real-world applications. In this paper, we introduce a new three-dimensional (3D) graphene structure printing approach with pure graphene oxide (GO) material, better interlayer bonding, and complex architecture printing capability. Various parameters related to this novel process are discussed in detail in order to improve the printability, reliability, and accuracy. We have shown that the print quality largely depends on the duty cycle of print head, applied pressure, and traveling velocity during printing. A set of printed samples are presented to demonstrate the effectiveness of the proposed technique along with the optimal parameter settings. The proposed process proves to be a promising 3D printing technique for fabricating multiscale nanomaterial structures. The theory revealed and parameters investigated herein are expected to significantly advance the knowledge and understanding of the fundamental mechanism of the proposed directional freezing-based 3D nano printing process. Furthermore, the outcome of this research has the potential to open up a new avenue for fabricating multifunctional nanomaterial objects.

Max–min Bin Packing Algorithm and its application in nano-particles filling

With regard to existing bin packing algorithms, higher packing efficiency often leads to lower packing speed while higher packing speed leads to lower packing efficiency. Packing speed and packing efficiency of existing bin packing algorithms including NFD, NF, FF, FFD, BF and BFD correlates negatively with each other, thus resulting in the failure of existing bin packing algorithms to satisfy the demand of nano-particles filling for both high speed and high efficiency. The paper provides a new bin packing algorithm, Max–min Bin Packing Algorithm (MM), which realizes both high packing speed and high packing efficiency. MM has the same packing speed as NFD (whose packing speed ranks no. 1 among existing bin packing algorithms); in case that the size repetition rate of objects to be packed is over 5, MM can realize almost the same packing efficiency as BFD (whose packing efficiency ranks No. 1 among existing bin packing algorithms), and in case that the size repetition rate of objects to be packed is over 500, MM can achieve exactly the same packing efficiency as BFD. With respect to application of nano-particles filling, the size repetition rate of nano particles to be packed is usually in thousands or ten thousands, far higher than 5 or 500. Consequently, in application of nano-particles filling, the packing efficiency of MM is exactly equal to that of BFD. Thus the irreconcilable conflict between packing speed and packing efficiency is successfully removed by MM, which leads to MM having better packing effect than any existing bin packing algorithm. In practice, there are few cases when the size repetition of objects to be packed is lower than 5. Therefore the MM is not necessarily limited to nano-particles filling, and can also be widely used in other applications besides nano-particles filling. Especially, MM has significant value in application of nano-particles filling such as nano printing and nano tooth filling.

Fabrication of Organic Thin Film Transistor(OTFT) Array by Using Nanoprinting Process

The flexible organic thin film transistor(OTFT) array to use as a switching device for an organic light emitting diode(OLED) was designed and fabricated in the nanocontact printing and low-temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by nanocontact printing process. And dielectric layer of parylene and organic active semiconductor layer of pentacene formed at room temperature or at a temperature lower than 40. The nanocontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a parylene.

‘New dimensions for manufacturing’ — A UK strategy for nanotechnology

This chapter discusses the nanotechnology and nano engineered membranes. Self-assembly of molecules or large groups of molecules is a key feature in nanotechnology. Nanotechnology deals with structures having at least 1D that is sufficiently small, of the order of about one to several hundred nanometers. It is concerned with materials and systems whose structures and components exhibit novel and improved physical, chemical, and biological properties. It enables the exploitation of novel phenomena and processes because of their nanoscale size. The chapter presents some examples of nano and micro engineered membrane technology and its use for nano engineered devices. A technique to pattern surfaces is to evaporate a target material through a thin membrane (shadow mask) with well-defined perforations. Photonic crystals are artificially three-dimensional structures fabricated in an optical material (crystal or amorphous) with unit cells whose dimensions are comparable to the optical wavelength. Nano and microsieves can be used as stencils for patterning, as photonic crystals, but they can also be used as a proper solid support for thin functional membranes. Nanotubes are the hollow cylindrical structures. The chapter discusses the nano printing and etching with phase separated membranes. Research goal in biomembrane science is to study the function of natural biomembranes and to engineer new types of biomembrane materials on the nanometer scale.