Aerosol Jet Deposition Research Articles

Composites Made of Carbon Nanotubes and Silver Nanoparticles for Conductive Aerosol-Jet Deposition Ink: The Double-Edged Sword of Functionalization

Optimizing conductive ink for Direct-Write Additive Manufacturing, this work explores the effect of carboxylic functionalization of multi-walled carbon nanotubes on their affinity to silver nanoparticles deposited on them. We show a correlation between functionalization and the size of the resulted NPs: the diameter of the silver NPs deposited on pristine CNTs (∼5 nm diameter) is third of that of NPs deposited on functionalized CNTs (∼15 nm). Electrical characterization of the silver-decorated CNT-based ink shows a more significant improvement in conductivity of the functionalized CNTs-decorated with silver compared to the pristine one (maximal ∼40 and ∼20% increase in conductivity over their undecorated counterpart, respectively). However, CNT functionalization severely damages the conductivity of the CNTs themselves, resulting in a much lower conductivity. This “double-edged sword” effect of functionalization results in the highest absolute specific conductivity (3.79 × 103 S/m) achieved by decorating pristine CNTs with 25 wt% of silver. Nevertheless, the observed enhanced conductivity and the ability to control the composite’s morphology by functionalization allow fine-tuning of morphology-based properties, such as surface enhanced Raman scattering and optimization of the ink for sensing applications.

Electrohydrodynamic and Aerosol Jet Printing for the Copatterning of Polydimethylsiloxane and Graphene Platelet Inks

AbstractThe performance of soft sensing and actuation devices is dependent on their design, the electro‐mechanical response of materials, and the ability to copattern structural and functional features. For film based soft structures, such as wearable sensors and artificial muscles, manufacturing challenges exist that prevent the translation of technology from laboratory to practical application. In this work, a hybrid manufacturing technique is presented that integrates electro‐hydrodynamic and aerosol jet deposition to print multilayer, multimaterial structures. The combined approach overcomes the respective rheological constraints of the individual processes, while presenting a pathway to higher resolution computer‐controlled patterning. Electro‐hydrodynamic deposition of a polydimethylsiloxane elastomer is demonstrated and characterized, before being combined with aerosol jet deposition of a graphene platelet ink to produce functional devices. A proof‐of‐concept, multilayer capacitive sensor is presented as a first demonstration of the manufacturing technology.

Wireless Resonant Circuits Printed Using Aerosol Jet Deposition for MRI Catheter Tracking.

Interventional magnetic resonance imaging (MRI) could allow for diagnosis and immediate treatment of ischemic stroke; however, such endovascular catheter-based procedures under MRI guidance are inherently difficult. One major challenge is tracking the tip of the catheter, as standard fabrication methods for building inductively coupled coil markers are rigid and bulky. Here, we report a new approach that uses aerosol jet deposition to three-dimensional (3-D) print an inductively coupled RF coil marker on a polymer catheter. Our approach enables lightweight conforming markers on polymer catheters and these low-profile markers allow the catheter to be more safely navigated in small caliber vessels. Prototype markers with an inductor with the geometry of a double helix are incorporated on catheters for in vitro studies, and we show that these markers exhibit good signal amplification. We report temperature measurements and, finally, demonstrate feasibility in a preliminary in vivo experiment. We provide material properties and electromagnetic simulation performance analysis. This paper presents fully aerosol jet-deposited and functional wireless resonant markers on polymer catheters for use in 3T clinical scanners.

High Capacity Rate Capable Aerosol Jet Printed Li‐Ion Battery Cathode

A thick (170 μm) LiFePO4 cathode is fabricated through aerosol jet printing. The printed cathode displays a pattern of aligned high aspect ratio needles which, in cross section, produce micron scale channels. These channels surround regions of LiFePO4 that possess submicron pores. When tested in half cell configuration versus a Li‐foil anode, the specific discharge capacity of the printed cathode is 151 mAh g−1 at a C/15 rate and 105 mAh g−1 at 1C. These values correspond to area normalized discharge capacities of 2.5 and 1.7 mAh cm−2 at current densities of 0.2 and 2.4 mA cm−2, respectively. In a 50 cycle constant current charge/discharge test, the discharge capacity is stable, retaining 89% of its initial C/5 capacity. These results suggest that aerosol jet deposition is a promising printing technique for fabricating high capacity, rate capable, Li‐ion battery cathodes.

Large area porous 1D photonic crystals comprising silicon hierarchical nanostructures grown by plasma-assisted, nanoparticle jet deposition

In this contribution, we describe a room-temperature, template-free, single-step approach for the growth of functional crystalline silicon nanostructures with tailored porosity and photonic properties. The method employs a plasma-assisted nanoparticle synthesis reactor in combination with a supersonic jet deposition stage, in what we call nanoparticle jet deposition or plasma-assisted, supersonic aerosol jet deposition. The relationship between plasma parameters, nanoparticle impaction conditions and the resulting silicon material structural characteristics is investigated. This understanding is successfully employed for the production of porous 1D photonic crystals obtained by periodically modulating the density of the hierarchical silicon nanostructures and hence their local refractive index. The open porosity of this device is then exploited in a proof of concept optical chemical sensor.

Printed-Sensor-on-Chip devices – Aerosol jet deposition of thin film relative humidity sensors onto packaged integrated circuits

In this paper we report on the development of an aerosol jet printed sensing platform integrating elements of silicon and printed electronics. To demonstrate the technology, thin film humidity sensors have been fabricated over the top surface and sides of pre-packaged integrated circuits using a combination of direct-write aerosol jet deposition and drop-casting. The resistive based sensor consists of an aerosol jet deposited interdigitated nano-particle silver electrode structure overlaid with a thin film of Nafion® acting as a humidity sensitive layer. The fabricated sensor displayed a strong response to changes in relative humidity over the tested range (40% RH–80% RH) and showed a low level of hysteresis whilst undergoing cyclic testing. The successful fabrication of relative humidity sensors over the surface and pins of a packaged integrated circuit demonstrates a new level of integration between printed and silicon based electronics – leading to Printed-Sensor-on-Chip devices. Whilst demonstrated for humidity, the proposed concept is envisaged to work as a platform for a wide range of applications, from bio-sensing to temperature or gas monitoring.

4-3: Wide Viewing Angle TN LCD Enhanced by Printed Quantum-Dots Film

The low heavy metal and heavy metal free QDs (Cd < 100 ppm, Pb-free) content of the R, G, B-QDs was deposited on top of the conventional twist nematic (TN) liquid crystal device to improve the viewing angle of liquid crystal display. The non-vacuum, low materials consumption solution process by aerosol-jet deposition has the advantage of direct printing on black matrix pattern glass. The intensity of 410 nm was applied to execite the QD film and was modulated by the TN cell. As a result, the LC retardation and response time can be fully optimized within the small cell gap. In particular, the eco-QD array TNLCD possesses wide viewing angle, high transmittance, and fast response time (< 3 ms) under low driving voltage (4 V).

Uniform Aerosol Jet printed polymer lines with 30 μm width for 140 ppi resolution RGB organic light emitting diodes

We demonstrate the patterning of top emitting organic light emitting diodes (OLEDs) by direct-write Aerosol Jet printing in air from non-halogenated solvents. Indane was determined to be a suitable single solvent to dissolve the archetypal host poly(N-vinylcarbazole) and guest emitting dopants complexes for red, green, and blue OLEDs, and to print on both PEDOT:PSS and MoO3 transport layers. The Aerosol Jet deposition parameters were studied, including: atomization flow rate, exhaust flow rate, focusing sheath flow rate, nozzle-to-substrate distance, nozzle speed, and substrate temperature. A line width of 30μm and thickness of 30nm was achieved, resulting in RGB OLEDs fabricated side-by-side with a pixel density of 140ppi.

Porous-wall Hollow Glass Microspheres for Security Printing Applications

Porous-wall hollow glass microspheres are a one-of-the-kind material with many potential uses in security technology. This work focuses on the development of security inks containing porous-wall hollow glass microspheres, whereby the microspheres serve as storage vessels for a variety of functional materials. This preliminary work comprises two feasibility studies. One study resulted in the successful aerosol jet deposition of hollow glass microspheres onto a substrate. The other study resulted in the loading of porous-wall hollow glass microspheres with gold nanoparticles. Both studies demonstrate the feasibility of developing and delivering a security ink utilizing porous-wall hollow glass microspheres that are loaded with functional materials. The results encourage the continuation of research to achieve this goal.

Self-biased Dual-phase Energy Harvesting System

ABSTRACTIn this study, we report the design and fabrication of a dual-phase energy harvester which can synchronously harvest both mechanical and magnetic energy in the absence of DC magnetic field. The harvester consists of a magnetostrictive cantilever beam and a magnetostrictive/ piezoelectric (M/P) self-biased laminate composite structure. This structure allows us to utilize piezoelectric and self-biased magnetoelectric effect simultaneously. By combining these mechanisms together, a sum effect for harvesting both magnetic and vibration energy was realized under DC magnetic field free condition. The bilayer structure provides a simplified geometry that can be easily incorporated into MEMS devices. We demonstrate a hybrid synthesis method for fabrication of complex three-dimensional thin films using a cost-effective and mask-less aerosol jet deposition process. The combination of the hybrid aerosol jet process with dual phase harvester design provides the opportunity to fabricate small scale power sources required for structural health monitoring applications.

Effect of the annealing process on CuInS2 thin films prepared by using aerosol jet deposition

CuInS2 thin films were prepared on soda lime glasses by using the aerosol jet deposition (AJD) method. The effects of the [Cu]/[In] ratio and the annealing process on the properties of the CuInS2 thin films were studied. The X-ray diffraction (XRD) analysis showed that well-crystallized films were deposited at a [Cu]/[In] ratio of 1.2 and a [S]/[In] ratio of 3. In order to improve the quality of the films, we explored various post-deposition annealing processes including furnace annealing in Ar, one-step sulfurization and two-step sulfurization. XRD and field emission scanning electron microscopy revealed that highly-crystallized grains were obtained in the films when two-step sulfurization was used. Energy dispersive X-ray analysis confirmed that two-step sulfurization in a H2S ambient eliminated the deficiency of sulfur and removed impurities such as oxygen and chlorine. The depth profiles of Cu, In and S for the CuInS2 films confirmed the effectiveness of two-step sulfurization for fabricating high quality CuInS2 films. Finally, deposition of high-quality CuInS2 films by using the AJD method could be achieved by the introduction of two-step sulfurization.

Characterization of CuInS2 thin films prepared by aerosol jet deposition

CuInS2 thin films were prepared using an aerosol jet deposition (AJD) technique with an aqueous solution of CuCl2, InCl3 and thiourea on a heated glass substrate. X-ray diffraction patterns showed that well-crystallized thin films with a preferential (112) orientation could be deposited at 400°C and [Cu]/[In] molar ratio of 1.2. Field emission scanning electron microscopy revealed well-crystallized grains in the films produced at high temperature of 400°C. In addition, energy dispersive X-ray spectroscopy confirmed that excess Cu and S were required to achieve well-crystallized CuInS2 films. As the [Cu]/[In] molar ratio increased from 0.8 to 1.4, the highest intensity of the (112) orientation and better crystallization were obtained at a [Cu]/[In] ratio of 1.2. The [Cu]/[In] ratios in the film were always higher than those in the precursor solution. All the CuInS2 thin films turned out to be p-type and had a band gap of 1.4eV. The depth profiles of Cu, In and S in the CuInS2 thin films deposited at the optimal [Cu]/[In] and [S]/[In] ratios of 1.2 and 3, respectively, were relatively constant throughout the films. Overall, the CuInS2 thin films deposited using the AJD method have well grown grains with good crystallinity.

Aerosol Jet® Printer as an Alternative to Wire Bond and TSV Technology for 3D Interconnect Applications

Aerosol Jet deposition systems provide an evolutionary alternative to both wire bond and TSV technology. As part of the Vertical Interconnect Pillar (ViP™) process, the Aerosol Jet system prints high density three-dimensional (3D) interconnects enabling multi-function integrated circuits to be stacked and vertically interconnected in high performance System-in-Packages (SiP). The stacks can include two or more die, with a total height of ∼ 2 millimeters. The non-contact printing system has a working distance of several millimeters above the substrate allowing 3D interconnects to be printed with no Z-height adjustments. The Aerosol Jet printhead is configured with multiple nozzles and a closely coupled atomizer to achieve production throughput of greater than 19,000 interconnects per hour. The Aerosol Jet printer deposits silver fine particle ink to form connections on staggered die stacks. High aspect ratio interconnects, less than 30-microns wide and greater than 6-microns tall, are printed at sub 60-micron pitch. After isothermal sintering at 150° C to 200° C for 30 minutes, highly conductive interconnects near bulk resistivity are produced. Pre-production yields exceeding 80% have been realized. This paper will provide further details on the 3D printed interconnect process, current and planned production throughput levels, and process yield and device reliability status.

Optically transparent, dense α-Al2O3 thick films deposited on glass at room temperature

Abstract Alumina films up to 5 μm thick have been deposited on fused silica and stainless steel substrates by a novel aerosol-jet deposition process at room temperature. The films are dense, uniform and adherent. Moreover, Al 2 O 3 film deposited on fused silica substrate is transparent for visible light. Transmittance of 1.5 μm thick alumina film is 83% measured at 800 nm, and that of 5.5 μm thick film is 68%. Scanning electron microscopy images and XRD analysis have revealed that the films have α-Al 2 O 3 crystallite structure however crystallite size is order of magnitude smaller than that raw material powder. Vickers microhardness of the films deposited on stainless steel has been measured. Aerosol-jet deposition becomes promising method for surface coating.

Processing and Applications of Aerosol‐Assisted Chemical Vapor Deposition

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Processing and Applications of Aerosol‐Assisted Chemical Vapor Deposition

AbstractThe aerosol‐assisted (AA) CVD method involves the atomization of a precursor solution into fine, sub‐micrometer‐sized aerosol droplets which are delivered to a heated reaction zone and undergo evaporation, decomposition, and homogeneous and/or heterogeneous chemical reactions to form the desired products. As a variant of conventional CVD processes, AACVD addresses the availability and delivery problems of the chemical precursors. A wide range of precursors can be used since volatility is no longer crucial, offering more possibilities to produce high‐quality CVD products at low cost. Some variants of AACVD have also been developed, such as AA combustion (C) CVD, electrostatic spray‐assisted vapor deposition (ESAVD), and electrostatic‐assisted aerosol jet deposition (EAAJD). These variants provide additional flexibility and capability to the AACVD‐based processes. AACVD‐based processes have attracted increasing interest in most of the CVD‐related areas, and have been widely used to synthesize various films, coatings, powders, composites, nanotubes and nanowires, etc. This review highlights the principles, applications, and recent progress of AACVD‐based processes.

Formation of Size-Selected Ni/NiO Core−Shell Particles by Pulsed Laser Ablation

This paper presents the method for fabricating size-selected nickel nanoparticles (diameter: 5−20 nm) coated with nickel oxide shells (thickness: about 2 nm). The core−shell particles were synthesized by a series of sequential gas-phase processes including pulsed laser ablation, aerosol postannealing, size-classification, compulsory oxidation, and aerosol-jet deposition. The change in the size distribution of the generated particles due to postannealing was measured by a low-pressure differential mobility analyzer (LP-DMA) coupled with a Faraday cup electrometer. The peak size decreased as the postannealing temperature rose, indicating that a sintering and restructuring of the agglomerates was taking place. In the high-resolution TEM (HRTEM) observation, the Ni particles of less than 15 nm in diameter were found to be spherical and single crystal after the annealing at 1073 K. The 20 nm particles were also spherical, but they remained polycrystalline due to insufficient annealing treatment required for ...

Electrostatic assisted aerosol jet deposition of CdS, CdSe and ZnS thin films

A high-efficiency deposition technique, electrostatic assisted aerosol jet deposition (EAAJD), has been used to prepare CdS, CdSe and ZnS thin films in an open atmosphere. The EAAJD method exhibited a higher deposition efficiency and film growth rate than conventional spray pyrolysis and chemical vapour deposition methods. The CdS and ZnS films produced using the EAAJD process showed a strong preferred orientation. Fine crystalline CdS and CdSe (grain size <200 nm) films were formed at temperatures as low as 300°C. ZnS film required a higher deposition temperature (>450°C) which resulted in large grain size (grain size ca. 500 nm). The optical properties of the CdS and CdSe showed that their bandgap values were very close to the values reported in literatures, indicating their potentials for the photovoltaic applications.

Microstructure and optical properties of CdSe thin films by electrostatic assisted aerosol jet deposition method

Microstructure and optical properties of CdSe thin films by electrostatic assisted aerosol jet deposition method

Synthesis, microstructure and optical properties of ZnS films formed by electrostatic assisted aerosol jet deposition

ZnS films were synthesised using a novel electrostatic assisted aerosol jet deposition (EAAJD) technique at temperatures above 450 °C from an aqueous solution of zinc chloride and thiourea. The films showed a mixture of hexagonal and cubic structures and strong preferred orientations, with the c-axis normal to film surface. Annealing at higher temperatures improved the crystallinity of the as-deposited films. However, ZnO was formed when the as-deposited films were annealed in air. The ZnS films exhibit a planar structure with small crystal sizes (<200 nm). The optical direct bandgap values (3.35–3.46 eV) of the as-deposited films were lower than reported values for polycrystalline ZnS, probably owing to their poor crystallinity and partial oxidation.