Controlling and assessing the quality of aerosol jet printed features for large area and flexible electronics

358

347

PE has been explored for the manufacturing of flexible and stretchable electronic devices by printing functional inks containing soluble or dispersed materials, [14][15][16] which has enabled a wide variety of applications, such as transparent conductive films (TCFs), flexible energy harvesting and storage, thin film transistors (TFTs), electroluminescent devices, and wearable sensors. [17][18][19][20][21][22][23][24] The global PE market should reach $26.6 billion by 2022 from $14.0 billion in 2017 at a compound annual growth rate of 13.6%. [25] PE devices are manufactured by a variety of printing technologies. Typical printing technologies can be divided into two broad categories: noncontact patterning (or nozzle-based patterning) and contact-based patterning. The noncontact techniques include inkjet printing, electrohydrodynamic (EHD) printing, aerosol jet printing, and slot die coating, while screen printing, gravure printing, and flexographic printing are examples of the contact techniques. Each of these techniques has its own advantages and disadvantages, but they all rely on the principle of transferring inks to a substrate. Understanding the characteristics and recent advances of each printing technique is important to further the progress in PE. Moreover, to promote the lab-scale printing technologies to large-scale production process, roll-toroll (R2R) printing, which is one of the manufacturing methods to obtain large-area films with low cost and excellent durability, has drawn much attention from both industry and the research community.Nearly all of devices based on PE require conductive structures, interconnects, and contacts; therefore, highly conductive patterns, usually with high transparency and/or high resolution, fabricated by means of printing conductive materials are one of the most critical components in PE devices. Various printable conductive nanomaterials, such as metal nanomaterials (e.g., metal nanoparticles and metal nanowires) and carbon nanomaterials (e.g., graphene and carbon nanotubes (CNTs)), have been explored and used as major materials for PE. Applying printing technology to deposition of the conductive nanomaterials requires formulation of suitable inks. After depositing inks on different substrates, post-printing treatment, Printed electronics is attracting a great deal of attention in both research and commercialization as it enables fabrication of large-scale, low-cost electronic devices on a variety of substrates. Printed electronics plays a critical role infacilitating widespread flexible electronics and more recently stretchable electronics. Conductive nanomaterials, such as metal nanoparticles and nanowires, carbon nanotubes, and graphene, are promising building blocks for printed electronics. Nanomaterial-based printing technologies, formulation of printable inks, post-printing treatment, and integration of functional devices have progressed substantially in the recent years. This review summarizes basic principles and recent development of common printing technologie...

Section: Printing Technology: Materials and Recent Developmentmentioning

confidence: 99%

Section: Printing Technology: Materials and Recent Developmentmentioning

confidence: 99%

Printing Conductive Nanomaterials for Flexible and Stretchable Electronics: A Review of Materials, Processes, and Applications

Huang

Zhu

2019

358

347

“…Here, we adopt an aerosol‐jet printing (AJP) technique to develop novel triboelectric sensors by the direct and rapid printing of both metallic and polymeric inks into the desired finely grated structures for high‐resolution motion sensing. AJP is a high‐resolution rapid‐prototyping facility that is compatible with a broad selection of inks with a wide range of viscosities . Inks are atomized by either pneumatic or ultrasonic excitation into micron‐sized aerosol droplets, which are carried in a nitrogen carrier gas to the printer nozzle, and focused into the desired size by the use of a sheath gas, such as nitrogen (as shown in Figure S1, Supporting Information).…”

Section: Introductionmentioning

confidence: 99%

“…Inks are atomized by either pneumatic or ultrasonic excitation into micron‐sized aerosol droplets, which are carried in a nitrogen carrier gas to the printer nozzle, and focused into the desired size by the use of a sheath gas, such as nitrogen (as shown in Figure S1, Supporting Information). A variety of compatible inks including those based on metallic and ceramic nanoparticles, carbon nanotubes, polymers, and polymeric precursors, with ink viscosities from 1 cP to 1000 cP can be directly printed with minimum feature size as small as 10 µm . AJP benefits from the ability to rapidly print customized patterns, as well as large working space (up to 175 mm × 200 mm in the Optomec AJ200 printer used in this work), making it a powerful tool for fabricating triboelectric nanogenerators in a scalable way.…”

Section: Introductionmentioning

confidence: 99%

Aerosol‐Jet Printed Fine‐Featured Triboelectric Sensors for Motion Sensing

Jing

Choi

Smith

et al. 2018

Self Cite

the relatively simple mechanism involved in converting mechanical energy into electrical signals, [15,16] wide material selection, [17,18] and light weight. [19] Triboelectric generators produce active electric output due to mechanical motion-driven contact electrification and charge induction. These generators can also be used as sensors, where the output signal can be monitored for sensing movement. [20][21][22][23][24] One particular type of triboelectric sensor designed for motion sensing, based on grated electrode structures on triboelectric surfaces, has been found to be potentially reliable, of high resolution, and direction sensitive with a wide selection of feasible materials. [25,26] Typically, these sensors comprise multiple alternating strips of two different triboelectric materials for contact electrification, and grated comb-like electrodes or interdigitated electrodes for charge induction. A commonly reported device structure involves a "mover" that slides over a "stator," with the contacting surface made up of triboelectric material strips, and the grated electrodes positioned on the backside of both the mover and the stator to form a sliding mode triboelectric sensor. [21] The relative sliding motion between the two different materials gives rise to a triboelectric charge that is picked up by the electrodes. If the electrodes are positioned only on the backside of the stator, then this structure gives rise to a freestanding mode triboelectric sensor (no electrical contact is needed from the mover). [27] To achieve high resolution, the metallic electrode gratings must be narrow (submillimeter), usually achieved via photolithography, [28] physical deposition, [26,29] or ion-etching [30] methods. These methods are not particularly cost effective and are generally inefficient for fast prototyping. At the same time, polymers that have good triboelectric properties are difficult to fabricate into the desired fine structures or finely patterned strips by the conventional lithography or physical deposition methods. This has led to the vast majority of the current grated-structure triboelectric sensors being built with metal strips as the active triboelectric material, [18,31] even though these are not particularly well-suited for triboelectric applications. Reports on all polymer-grated triboelectric sensors are thus tellingly rare, even though such devices could potentially offer better resolution and higher signal-to-noise ratios in motion sensing applications.Triboelectric motion sensors, based on the generation of a voltage across two dissimilar materials sliding across each other as a result of the triboelectric effect, have generated interest due to the relative simplicity of the typical grated device structures and materials required. However, these sensors are often limited by poor spatial and/or temporal resolution of motion due to limitations in achieving the required device feature sizes through conventional lithography or printing techniques. Furthermore, the reliance on metallic components t...

“…Despite these advantages, in extrusion‐printing, composition and rheological behaviors of inks are demanding due to the requirements in clogging prevention, substrate bonding and shape maintenance . Alternatively, aerosol printing processes a wide variety of materials, including polymers, metallic conductors, semiconductors, carbon‐based nanomaterials, and energy materials in laden inks with a wider range of viscosity from 1 to 1000 cP . Aerosol printing utilizes moderately pressurized air to nebulize the active materials into aerosol mist and drive the precise material deposition with smallest feature size down to 10 µm .…”

mentioning

confidence: 99%

Customizable Nonplanar Printing of Lithium‐Ion Batteries

Liu

Pham

et al. 2019

widely used in consumer electronics due to the advantages of rechargeability and high energy density. [4][5][6] Commercial LIBs are usually fabricated in fixed geometry such as cylinder, coin, and pouch with scrolled or layered planar sheets for each component. [7] Nevertheless, LIBs with customizable geometry are desired for specialized applications such as wearable electronics [8,9] and on-device power systems [10,11] for automobile and aerospace vehicles, For example, LIBs can be made into a watchband to power an electronic watch, [12] which eliminates the installation and replacement of coin cell. To meet such demands, irregular, customizable LIBs in arbitrary geometry on 3D structures along with the packaging, integrating, and manufacturing approaches need to be developed. So far, the most effective solution to fabricate freeform LIBs is additive manufacturing (AM, popularly known as 3D printing). [13][14][15][16] The on-demand and layer-by-layer manufacturing method has provided the flexibility to accommodate customizable designs of 3D LIBs.Electrodes are the most essential components of LIBs. Currently reported AM processes for electrodes are mostly based on extrusion printing, [17][18][19][20][21][22][23][24] with a few reports on other ink-based printing methods including inkjet printing [25] and aerosol printing. [10] In extrusion printing, active material laden inks are directly deposited and powered by ultra-high air pressure. The materials are extruded into semi-solidified and self-supportive filaments owing to the shear-thinning characteristics of the highly viscous inks. Main advantage of AM processes is the capability of printing electrodes in arbitrary geometry. For example, Lacey et al. and Wang et al. demonstrated 3D printing of mesh and lattice structured electrodes, which effectively introduced macroporosity and facilitated the transportation of lithium-ions under high charging/discharging rate. [18,23] The flexibility in printed geometry also enables the fabrication of electrodes with high aspect ratio and high areal capacity, which are usually not processable by conventional slurry-casting method. Sun et al. first printed high aspect ratio, multilayer, interdigitated electrodes for micro-LIBs with high energy density and power density. [21] Despite these advantages, in extrusion-printing, composition and rheological behaviors of inks are demanding due to the requirements in clogging prevention, substrate bonding and shape maintenance. [19,20] Alternatively, aerosol printing Lithium-ion batteries (LIBs) are widely used in consumer electronics due to their rechargeability and high energy density. Commercial LIBs are fabricated in fixed geometries such as cylinder, coin, and pouch. However, for specialized applications such as wearable electronics and on-device power systems, customizable LIBs with arbitrary geometry on threedimensional (3D) structures need to be developed. For this purpose, aerosol printing is uniquely suitable due to its flexible working distance, allowing deposition on nonp...