When circuits are printed, labels can talk - New nanomaterials enable low cost flexible electronics

Abstract Recently, the three-dimensional (3D) printing technique has attracted much attention for creating objects of arbitrary shape and manufacturing. For the first time, in this work, we present the fabrication of an inkjet printed low-cost 3D temperature sensor on a 3D-shaped thermoplastic substrate suitable for packaging, flexible electronics, and other printed applications. The design, fabrication, and testing of a 3D printed temperature sensor are presented. The sensor pattern is designed using a computer-aided design program and fabricated by drop-on-demand inkjet printing using a magnetostrictive inkjet printhead at room temperature. The sensor pattern is printed using commercially available conductive silver nanoparticle ink. A moving speed of 90 mm/min is chosen to print the sensor pattern. The inkjet printed temperature sensor is demonstrated, and it is characterized by good electrical properties, exhibiting good sensitivity and linearity. The results indicate that 3D inkjet printing technology may have great potential for applications in sensor fabrication.

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Preparation and application of water-based nano-silver conductive ink in paper-based 3D printing

Rapid Prototyping Journal ◽

10.1108/rpj-05-2020-0112 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Chenfei Zhao ◽

Jun Wang ◽

Lini Lu

Keyword(s):

Flexible Electronics ◽

Low Cost ◽

Methyl Cellulose ◽

Conductive Ink ◽

Content Type ◽

Nano Silver ◽

Printed Circuit ◽

Silver Ink ◽

Sintering Time ◽

Water Based

Purpose In flexible electronics applications, organic inks are mostly used for inkjet printing. Three-dimensional (3 D) printing technology has the advantages of low cost, high speed and good precision in modern electronic printing. The purpose of this study is to solve the high cost of traditional printing and the pollution emissions of organic ink. It is necessary to develop a water-based conductive ink that is easily degradable and can be 3 D printed. A nano-silver ink printed circuit pattern with high precision, high conductivity and good mechanical properties is a promising strategy. Design/methodology/approach The researched nano-silver conductive ink is mainly composed of silver nanoparticles and resin. The effect of adding methyl cellulose on the ink was also explored. A simple 3 D circuit pattern was printed on photographic paper. The line width, line length, line thickness and conductivity of the printed circuit were tested. The influence of sintering temperature and sintering time on pattern resistivity was studied. The relationship between circuit pattern bending performance and electrical conductivity is analyzed. Findings The experimental results show that the ink has the characteristics of low silver content and good environmental protection effect. The printing feasibility of 3 D printing circuit patterns on paper substrates was confirmed. The best printing temperature is 160°C–180°C, and the best sintering time is 30 min. The circuit pattern can be folded 120°, and the cycle is folded more than 60 times. The minimum resistivity of the circuit pattern is 6.07 µΩ·cm. Methyl cellulose can control the viscosity of the ink. The mechanical properties of the pattern have been improved. The printing method of 3 D printing can significantly reduce the sintering time and temperature of the conductive ink. These findings may provide innovation for the flexible electronics industry and pave the way for alternatives to cost-effective solutions. Originality/value In this study, direct ink writing technology was used to print circuit patterns on paper substrates. This process is simple and convenient and can control the thickness of the ink layer. The ink material is nonpolluting to the environment. Nano-silver ink has suitable viscosity and pH value. It can meet the requirements of pneumatic 3 D printers. The method has the characteristics of simple process, fast forming, low cost and high environmental friendliness.

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Bias Stress in Organic Thin-Film Transistors Towards Low-Cost Flexible Gas Sensors

Journal of Integrated Circuits and Systems ◽

10.29292/jics.v16i2.197 ◽

2021 ◽

Vol 16 (2) ◽

pp. 1-11

Author(s):

José Enrique Eirez Izquierdo ◽

José Diogo da Silva Oliveira ◽

Vinicius Augusto Machado Nogueira ◽

Dennis Cabrera García ◽

Marco Roberto Cavallari ◽

...

Keyword(s):

Thin Film ◽

Flexible Electronics ◽

Thin Film Transistors ◽

Low Cost ◽

Thin Film Deposition ◽

Dielectric Surface ◽

Organic Thin Film Transistors ◽

Film Deposition ◽

Organic Thin Film ◽

Bias Stress

This work is focused on the bias stress (BS) effects in Organic Thin-Film Transistors (OTFTs) from poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14) on both highly-doped Si and glass substrates. While the former had a thermally-grown SiO2 dielectric, the latter demanded an alternative dielectric that should be capable to withstand bottom contact lithography, as well as semiconducting thin-film deposition. In addition, it should represent one more step towards flexible electronics. In order to do that, poly(4-vinylphenol) (PVP) was blended to poly(melamine-co-formaldehyde) methylated (PMF). OTFTs on glass with a cross-linked polymer dielectric had a charge carrier mobility (μ) of 4.0x10-4 cm2/Vs, threshold voltage (VT) of 18 V, current modulation (ION/OFF) higher than 1x102, and subthreshold slope (SS) of -7.7 V/dec. A negative BS shifted VT towards negative values and produced an increase in ION/OFF. A positive BS, on the other hand, produced the opposite effect only for OTFTs on Si. This is believed to be due to a higher trapping at the PVP:PMF interface with PBTTT-C14. Modeling the device current along time by a stretched exponential provided shorter time constants of ca. 105 s and higher exponents of 0.7–0.9 for devices on glass. Due to the presence of increased BS effects, the application of organic TFTs based on PVP:PMF as flexible sensors will require compensating circuits, lower voltages or less measurements in time. Alternatively, BS effects could be reduced by a dielectric surface treatment.

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Localized Laser Sintering of Metal Nanoparticle Inks Printed with Aerosol Jet® Technology for Flexible Electronics

Journal of Microelectronics and Electronic Packaging ◽

10.4071/imaps.521797 ◽

2017 ◽

Vol 14 (4) ◽

pp. 132-139 ◽

Cited By ~ 10

Author(s):

Michael J. Renn ◽

Matthew Schrandt ◽

Jaxon Renn ◽

James Q. Feng

Keyword(s):

Metal Nanoparticles ◽

Flexible Electronics ◽

Low Cost ◽

Damage Threshold ◽

Laser Sintering ◽

Heating Time ◽

Metal Nanoparticle ◽

Polymer Materials ◽

Nanoparticle Inks ◽

Short Heating Time

Direct-write methods, such as the Aerosol Jet® technology, have enabled fabrication of flexible multifunctional 3-D devices by printing electronic circuits on thermoplastic and thermoset polymer materials. Conductive traces printed by additive manufacturing typically start in the form of liquid metal nanoparticle inks. To produce functional circuits, the printed metal nanoparticle ink material must be postprocessed to form conductive metal by sintering at elevated temperature. Metal nanoparticles are widely used in conductive inks because they can be sintered at relatively low temperatures compared with the melting temperature of bulk metal. This is desirable for fabricating circuits on low-cost plastic substrates. To minimize thermal damage to the plastics, while effectively sintering the metal nanoparticle inks, we describe a laser sintering process that generates a localized heat-affected zone (HAZ) when scanning over a printed feature. For sintering metal nanoparticles that are reactive to oxygen, an inert or reducing gas shroud is applied around the laser spot to shield the HAZ from ambient oxygen. With the shroud gas-shielded laser, oxygen-sensitive nanoparticles, such as those made of copper and nickel, can be successfully sintered in open air. With very short heating time and small HAZ, the localized peak sintering temperature can be substantially higher than that of damage threshold for the underlying substrate, for effective metallization of nanoparticle inks. Here, we demonstrate capabilities for producing conductive tracks of silver, copper, and copper–nickel alloys on flexible films as well as fabricating functional thermocouples and strain gauge sensors, with printed metal nanoparticle inks sintered by shroud-gas-shielded laser.

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One-pot synthesis of a stable and cost-effective silver particle-free ink for inkjet-printed flexible electronics

Journal of Materials Chemistry C ◽

10.1039/d0tc03864d ◽

2020 ◽

Vol 8 (46) ◽

pp. 16443-16451

Author(s):

Wendong Yang ◽

Florian Mathies ◽

Eva L. Unger ◽

Felix Hermerschmidt ◽

Emil J. W. List-Kratochvil

Keyword(s):

Flexible Electronics ◽

Silver Particle ◽

Low Cost ◽

Cost Effective ◽

Good Stability ◽

Flexible Substrates ◽

One Pot ◽

One Pot Synthesis ◽

Do It Yourself

A do-it-yourself silver particle-free ink is presented, which shows good stability, low cost and excellent printability. The ink is formulated in selected alcohols. Highly conductive silver patterns were printed on both glass and flexible substrates.

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Low cost and highly conductive elastic composites for flexible and printable electronics

Journal of Materials Chemistry C ◽

10.1039/c6tc01340f ◽

2016 ◽

Vol 4 (24) ◽

pp. 5839-5848 ◽

Cited By ~ 40

Author(s):

Yougen Hu ◽

Tao Zhao ◽

Pengli Zhu ◽

Yu Zhu ◽

Xingtian Shuai ◽

...

Keyword(s):

Flexible Electronics ◽

Low Cost ◽

High Conductivity ◽

Printable Electronics ◽

Conductive Composites ◽

Conductive Elastic Composites ◽

Elastic Composites

Printable elastic conductive composites with high conductivity and flexibility have exciting applications in burgeoning flexible electronics.

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Inkjet-Printed Graphene-Based 1 × 2 Phased Array Antenna

Micromachines ◽

10.3390/mi11090863 ◽

2020 ◽

Vol 11 (9) ◽

pp. 863

Author(s):

Mahmuda Akter Monne ◽

Peter Mack Grubb ◽

Harold Stern ◽

Harish Subbaraman ◽

Ray T. Chen ◽

...

Keyword(s):

Flexible Electronics ◽

Field Effect ◽

Phased Array ◽

Field Effect Transistors ◽

Low Cost ◽

Array Antenna ◽

Phased Array Antenna ◽

Field Patterns ◽

Radiating Element ◽

True Time

Low-cost and conformal phased array antennas (PAAs) on flexible substrates are of particular interest in many applications. The major deterrents to developing flexible PAA systems are the difficulty in integrating antenna and electronics circuits on the flexible surface, as well as the bendability and oxidation rate of radiating elements and electronics circuits. In this research, graphene ink was developed from graphene flakes and used to inkjet print the radiating element and the active channel of field effect transistors (FETs). Bending and oxidation tests were carried out to validate the application of printed flexible graphene thin films in flexible electronics. An inkjet-printed graphene-based 1 × 2 element phased array antenna was designed and fabricated. Graphene-based field effect transistors were used as switches in the true-time delay line of the phased array antenna. The graphene phased array antenna was 100% inkjet printed on top of a 5 mil flexible Kapton® substrate, at room temperature. Four possible azimuth steering angles were designed for −26.7°, 0°, 13°, and 42.4°. Measured far-field patterns show good agreement with simulation results.

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Organic–inorganic hybrid thin films based in HfO2 nanoparticles as dielectric for flexible electronics

Canadian Journal of Physics ◽

10.1139/cjp-2013-0570 ◽

2014 ◽

Vol 92 (7/8) ◽

pp. 806-812 ◽

Cited By ~ 2

Author(s):

R. Ambrosio ◽

O. Arciniega ◽

A. Carrillo ◽

M. Moreno ◽

A. Heredia ◽

...

Keyword(s):

Band Gap ◽

Hybrid Material ◽

Flexible Electronics ◽

Photoelectron Spectroscopy ◽

Hafnium Oxide ◽

Optical Band Gap ◽

Low Cost ◽

Sol Gel ◽

Inorganic Hybrid

In this work the synthesis and characterization of an organic–inorganic hybrid composite film based on hafnium oxide (HfO2) and polyvinylpyrrolidone (PVP) with dielectric properties is presented. These films were prepared using the sol-gel process adjusting the chemical composition to tailor the material properties, such as the dielectric and the optical band gap. The HfO2 was obtained by the hydrolysis of hafnium chloride (HfCl4) under catalysis of ethanol and deionized water, later the PVP was subsequently added to complete the hydrolysis. Finally the films were dried at 150 °C. The structural characterization of the hybrid material showed a hafnium nanoparticle size around 100 nm into the polymer matrix. The chemical structure and the high purity of the hybrid material were corroborated by X-ray photoelectron spectroscopy measurements, which showed the bounding of HfO2–PVP. The electrical characterization demonstrated that the nanostructured materials with hafnium nanoparticles improve the dielectric constant in the films with values around k = 18.5. The optical band gap, Eo, was obtained from 4 to 5.7 eV. These characteristics in our hybrid material are very promising for flexible electronics applications with the advantage of its low temperature, thermal stability, and low cost process of deposition.

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A Molecular Dynamics Simulation Study: The Inkjet Printing of Graphene Inks on Polyimide Substrates

Frontiers in Materials ◽

10.3389/fmats.2021.769071 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lingjun Wu ◽

Wei Wang ◽

Haitao Zhao ◽

Libo Gao ◽

Jibao Lu ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Adhesion Strength ◽

Simulation Study ◽

Flexible Electronics ◽

Inkjet Printing ◽

Low Cost ◽

Interfacial Instability ◽

Atomic Scale ◽

Dynamics Simulation

Inkjet printing-based 2D materials for flexible electronics have aroused much interest due to their highly low-cost customization and manufacturing resolution. However, there is a lack of investigation and essential understanding of the surface adhesion affected by the printing parameters at the atomic scale. Herein, we conducted a systematic molecular dynamics simulation investigating the inkjet printing of graphitic inks on polyimide substrates under various conditions. Simulations under different temperatures, inkjet velocities, and mechanical loadings such as pressure and deformation are performed. The results show that the best adhesion is achieved in the plasma-modified polyimide/graphene-oxide (mPI/GO) interfacial system (the interaction energy (Ein) between mPI and GO is ca. 1.2 times than with graphene). The adhesion strength decreases with increasing temperature, and higher inkjet velocities lead to both larger impact force as well as interfacial fluctuation, while the latter may result in greater interfacial instability. When loaded with pressure, the adhesion strength reaches a threshold without further improvement as continuing compacting of polymer slabs can hardly be achieved. The detachment of the interfaces was also explored and mPI/GO shows better resistance against delamination. Hopefully, our simulation study paves the way for future inkjet printing-based manufacturing of graphene-based flexible electronics.

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Development of Dielectric Film Based on Cellulose Loaded Nano-Silver and Carbon for Potential Energy Storage

ECS Journal of Solid State Science and Technology ◽

10.1149/2162-8777/ac3d1c ◽

2021 ◽

Author(s):

Sawsan Dacrory ◽

Samir Kamel ◽

G. M. Turky

Keyword(s):

Temperature Dependence ◽

Flexible Electronics ◽

Low Cost ◽

Broad Band ◽

Periodate Oxidation ◽

Interfacial Polarization ◽

Single Step ◽

Arrhenius Behavior ◽

X Ray ◽

Nano Silver

Abstract Cellulose has attracted much attention as a potential substrate for low-cost, flexible electronics. Here, new cellulose-based films embedded with nano-silver (AgNs) and carbon (C) were successfully prepared. First, cellulose was oxidized to tricarboxy cellulose (TCC) using 2,2,6,6 tetramethylpiperidine-1-oxyl followed by periodate oxidation. Then, nano-silver was prepared by polyol method and carbon was prepared via a single-step from bagasse. The structure, thermal, morphology, mechanical properties, and broad-band were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy with energy-dispersive X-ray, X-ray diffraction, and stress-strain relation. The results showed that the tensile strength and thermal stability of the films were improved. The temperature dependence of permittivity,  of the TCC film, increased in two trends. However, TCC film shows non-conducting features, especially at lower temperatures; its nanocomposites films show a semiconducting behavior, and its ac-conductivity follows the empirical Jonscher law. Although the temperature dependence of dc-conductivity of the TCC/C, shows an Arrhenius behavior with low activation energy (≈ 3.74 kJ/mol.), its investigated nanocomposites follow the well-known Vogel Fulcher Tamman equation according to the fragility of the prepared samples and/or the correlation between the interfacial polarization and conductivity.

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