Printable Electronics Research Articles

Simulation and Experimental Research on the Effect of Scraper Pressure on Pattern Transferring Process of Gravure Printed Electronic Equipment

Printed electronics is a new technology for manufacturing electronic products. However, the existing printing technologies could not meet the requirements for high precision of printing as required for producing silicon microelectronic devices. A regulation method is proposed to solve the problem of forming precision control of the pattern in gravure printing electronics. Based on the Navier–Stokes equations and Continuity equation for Newton flow, the relationship between ink flow velocity and scraper pressure change is studied. Thus, the coupling effect of cell ceiling, scraper shape and ink is analyzed by numerical decoupling method. ANSYS CFX is used to simulate the velocity of the ink transferring process. The scraper deformation and ink film thickness uniformity were tested and measured. According to the simulation and test results, the model is modified. Research findings: Under the printing pressure, the deformation in the middle of the doctor blade is slightly lower than that at both ends. When the initial printing pressure is constant, most ink uneven streaks appear at 1/2-1/3 of the doctor blade. It is shown that increasing the initial angle of the scraper can improve the printing precision of the gravure printing electronic equipment via the reasonable matching of the initial angle by the roller scraper pressure.

Unraveling the Steric Link to Copper Precursor Decomposition: A Multi-Faceted Study for the Printing of Flexible Electronics.

The field of printed electronics strives for lower processing temperatures to move toward flexible substrates that have vast potential: from wearable medical devices to animal tagging. Typically, ink formulations are optimized using mass screening and elimination of failures; as such, there are no comprehensive studies on the fundamental chemistry at play. Herein, findings which describe the steric link to decomposition profile: combining densityfunctionaltheory, crystallography, thermal decomposition, mass spectrometry, and inkjet printing, are reported. Through the reaction of copper(II) formate with excess alkanolamines of varying steric bulk, tris-co-ordinated copper precursor ions: "[CuL3 ]," each with a formate counter-ion (1-3) are isolated and their thermal decomposition mass spectrometry profiles are collected to assess their suitability for use in inks (I1-3 ). Spin coating and inkjet printing of I1,2 provides an easily up-scalable method toward the deposition of highly conductive copper device interconnects (ρ = 4.7-5.3 × 10-7 Ω m; ≈30% bulk) onto paper and polyimide substrates and forms functioning circuits that can power light-emitting diodes. The connection among ligand bulk, coordination number, and improved decomposition profile supports fundamental understanding which will direct future design.

Liquid metal enabled conformal electronics.

The application of three-dimensional common electronics that can be directly pasted on arbitrary surfaces in the fields of human health monitoring, intelligent robots and wearable electronic devices has aroused people's interest, especially in achieving stable adhesion of electronic devices on biological dynamic three-dimensional interfaces and high-quality signal acquisition. In recent years, liquid metal (LM) materials have been widely used in the manufacture of flexible sensors and wearable electronic devices because of their excellent tensile properties and electrical conductivity at room temperature. In addition, LM has good biocompatibility and can be used in a variety of biomedical applications. Here, the recent development of LM flexible electronic printing methods for the fabrication of three-dimensional conformal electronic devices on the surface of human tissue is discussed. These printing methods attach LM to the deformable substrate in the form of bulk or micro-nano particles, so that electronic devices can adapt to the deformation of human tissue and other three-dimensional surfaces, and maintain stable electrical properties. Representative examples of applications such as self-healing devices, degradable devices, flexible hybrid electronic devices, variable stiffness devices and multi-layer large area circuits are reviewed. The current challenges and prospects for further development are also discussed.

Fully Sprayed Metal Oxide Transistors Utilizing Ti3C2Tx MXene Contacts

Printable large-area electronics continue to attract increasing interest from the scientific and industrial communities, owing to their potential for cost-efficient manufacturing. However, the exerted efforts primarily focus on processing semiconductors and dielectrics, with relatively limited attention toward printable electrode materials. In this respect, the family of two-dimensional (2D) transition metal carbides/nitrides, so-called MXenes, have emerged as promising electrode materials owing to their metal-like conductivity and solution processability. Despite their advantageous characteristics, however, to date, the application of MXene electrodes in the area of printed electronics has been marginally explored. Herein, we develop all-solution-processable In2O3/ZnO heterojunction metal oxide thin-film transistors (TFTs) utilizing Ti3C2Tx MXene as the gate and the electron-injecting contacts, entirely spray-coated under ambient conditions. We show that the manufacturing of these fully spray-coated devices can be scaled-up to 4 in. substrates without compromising their operating characteristics. The fabricated TFTs exhibit electron mobility of 3 cm2 V–1 s–1 with an on/off ratio of >104. Our findings demonstrate the possibility of replacing conventional metal contacts with spray-coated MXene electrodes for application in large-area electronics.

Remote Monitoring of Skin Temperature Through a Wristband Employing a Printed VO Sensor

The need for highly sensitive, environmentally stable, mechanically flexible, and low-cost temperature sensors for on-body measurements has been increasing with the wide adoption of personal healthcare-Internet-of-Things (H-IoT) devices. Printed electronics (PE) is a good platform for such sensors because it enables the realization of flexible devices through simple and rapid methods at a relatively low cost. However, previously reported printed temperature sensors suffer from poor sensitivity and/or environmental instability. In this article, we report a custom tungsten (W)-doped vanadium dioxide (VO2) ink-based screen-printed temperature sensor having the highest temperature coefficient of resistance (TCR) of 2.78% C-1 with a resolution of 0.1 °C between 30 °C and 40 °C. To protect it from environmental effects, a fluoropolymer-basedpassivation layer is added for accurate temperature readings even in 90% relative humidity. The sensor is printed on a flexible substrate and shows minimal deterioration in performance over 1000 bending cycles. For wearability and remote monitoring, the sensor is integrated with a custom Bluetooth low energy (BLE) wireless readout in the form of wristband. The BLE readout comprises an ultrathin and flexible patch antenna optimized for both BLE bandwidth (BW) and human wearability. It demonstrates a minimal specific absorption rate (SAR) value of only 0.068 W/kg, making it safe to wear. Despite the antenna’s thin structure (0.004λ), it has a gain of 1.65 dBi, enabling an excellent communication range. The proposed wristband is tested on ten volunteers and under daily activities, which shows promising results with a maximum error of 0.16 °C with reference to those of a commercial thermometer.

Driving sustainability beneath the surface

As part of the interview series with members of the OE-A Working Group Sustainability, OPE journal interviewed Carla Negele, Head of Product Development Printed Electronics, and Melanie Wendrikat, Market Strategy Manager Printed Electronics at Henkel, on sustainability aspects of their company’s solutions

Self-poled and transparent polyvinylidene fluoride-co-hexafluoropropylene-based piezoelectric devices for printable and flexible electronics.

Transparent and flexible energy supply devices are becoming increasingly important for human interfaces as the Internet of Things (IoT) continues to grow. In this study, self-poled and transparent piezoelectric nanogenerators (ST-PENGs) based on 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFOES) and polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) composite films were prepared via extrusion printing, where PFOES induces the transformation of PVDF-HFP chains, exhibiting a higher β-phase content and remarkable piezoelectric properties. The hydrogen bonding interaction between the PVDF-HFP matrix and the PFOES agents causes a clear transition from phase to phase, as evidenced by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results. Moreover, the PFOES content influences the β-phase content, with 10 wt% of PFOES enabling the induction of the β-phase content up to 82.7%. The proposed ST-PENGs generate an excellent output voltage, power, and sensitivity of ∼6.2 V, ∼6.9 μW cm-2, and ∼131.3 mV N-1, respectively, exhibiting a record-high improvement compared with previously reported PENGs. These ST-PENGs also offer significant promise in tracking human activity and recovering biomechanical energy. This study may provide insight into the development of transparent and flexible piezoelectric devices to achieve high-performance self-powered electronics.

Reliability of printed stretchable electronics based on nano/micro materials for practical applications.

Recent decades have witnessed the booming development of stretchable electronics based on nano/micro composite inks. Printing is a scalable, low-cost, and high-efficiency fabrication tool to realize stretchable electronics through additive processes. However, compared with conventional flexible electronics, stretchable electronics need to experience more severe mechanical deformation which may cause destructive damage. Most of the reported works in this field mainly focus on how to achieve a high stretchability of nano/micro composite conductors or single working modules/devices, with limited attention given to the reliability for practical applications. In this minireview, we summarized the failure modes when printing stretchable electronics using nano/micro composite ink, including dysfunction of the stretchable interconnects, the stress-concentrated rigid-soft interfaces for hybrid electronics, the vulnerable vias upon stretching, thermal accumulation, and environmental instability of stretchable materials. Strategies for tackling these challenges to realize reliable performances are proposed and discussed. Our review provides an overview on the importance of reliable, printable, and stretchable electronics, which are the key enablers in propelling stretchable electronics from fancy demos to practical applications.

Monolithic Tandem Vertical Electrochemical Transistors for Printed Multi-Valued Logic.

Organic electrochemical transistors (OECTs) have recently emerged as a feasible candidate to realize the next generation of printable electronics. Especially, their chemical versatility and the unique redox-based operating principle have provided new possibilities in high-functioning logic circuitry beyond the traditional binary Boolean logic. Here, a simple strategy to electrochemically realize monolithic multi-valued logic transistors is presented, which is one of the most promising branches of transistor technology in the forthcoming era of hyper Moore's law. A vertically stacked heterogeneous dual-channel architecture is introduced with a patterned reference electrode, which enables a facile manifestation of stable and equiprobable ternary logic states with a reduced transistor footprint. The dual-ion-penetration mechanism coupled with ultrashort vertical channel even allows a very-high accessing frequency to multiple logic states reaching over 10MHz. Furthermore, printed arrays of ternary logic gates with full voltage swing within 1V are demonstrated.

Inkjet-printed h-BN memristors for hardware security.

Inkjet printing electronics is a growing market that reached 7.8 billion USD in 2020 and that is expected to grow to ∼23 billion USD by 2026, driven by applications like displays, photovoltaics, lighting, and radiofrequency identification. Incorporating two-dimensional (2D) materials into this technology could further enhance the properties of the existing devices and/or circuits, as well as enable the development of new concept applications. Along these lines, here we report an easy and cheap process to synthesize inks made of multilayer hexagonal boron nitride (h-BN)-an insulating 2D layered material-by the liquid-phase exfoliation method and use them to fabricate memristors. The devices exhibit multiple stochastic phenomena that are very attractive for use as entropy sources in electronic circuits for data encryption (physical unclonable functions [PUFs], true random number generators [TRNGs]), such as: (i) a very disperse initial resistance and dielectric breakdown voltage, (ii) volatile unipolar and non-volatile bipolar resistive switching (RS) with a high cycle-to-cycle variability of the state resistances, and (iii) random telegraph noise (RTN) current fluctuations. The clue for the observation of these stochastic phenomena resides on the unpredictable nature of the device structure derived from the inkjet printing process (i.e., thickness fluctuations, random flake orientations), which allows fabricating electronic devices with different electronic properties. The easy-to-make and cheap memristors here developed are ideal to encrypt the information produced by multiple types of objects and/or products, and the versatility of the inkjet printing method, which allows effortless deposition on any substrate, makes our devices especially attractive for flexible and wearable devices within the internet-of-things.

Public Relations Strategy in Handling Public Complaints: Case on PT. PLN (Persero) Region South Sumatra, Jambi, and Bengkulu

Power outages and electricity in the Palembang area are quite a problem. This situation has caused many complaints to (State Electricity Company/PLN) to re-solve this electricity service problem. Complaints from the public are received by the call center 123 and PLN PR officers. The title of the research is how is PLN's PR strategy in handling public complaints about Power Blackouts in Palembang? This study uses the Theory of Reduce Uncertainty and a strategy of complaint handling Public Relations with a qualitative descriptive method. The subject of this research is Public Relations officer of PLN WS2JB Palembang. The focus of this research is the strategy of the Public Relations section of PLN WS2JB in handling public complaints. The results obtained are PLN WS2JB Public Relations officers provide a place to complain verbally or non-verbally, and then conduct a corporation with Corporate Social Responsibility (CSR), then provide information on electricity and electricity outage schedules through media and official letters by PLN to Giant customers, and t Finally, I apologize to the public if the electricity goes out suddenly/accidentally without notification in the media, whether electronic media, social media, or print media.

Strategi Fundraising Zakat Pada Baznas Provinsi Sumatera Barat

Badan Amil Zakat Nasional is a nonstructural government agency that is independentand responsible to the president through ministers. BAZNAS is an institution that is authorized to carry out the task of managing zakat nationally. The purpose of this study is to determine the strategy carried out by BAZNAS of West Sumatra Province in zakat fundraising activities. The main problem in this study is the strategy carried out by the National Amil Zakat Agency of West Sumatra Province in zakat fundraising activities. The type of research that the author uses is field research with qualitative methods (field research). The data collection techniques that the author did were field observations, interviews with the National Amil Zakat Agency and documentation. Data analysis techniques are data reduction, data presentation and drawing conclusions. The results of this study show that the fundraising strategy carried out by the National Zakat Agency of West Sumatra Province is to use two fundraising methods, namely online and offline methods (direct and indirect). Direct fundraising is to approach local governments, conduct hearings with institutions, socialize zakat, carry out zakat pick-up services and indirect fundraising such as maximizing the use of electronic media and print media. The main obstacle is that the fundraising strategy prepared by BAZNAS of West Sumatra Province has been fully implemented in the field but the level of effectiveness is still low. BAZNAS of West Sumatra Province has not optimally worked on the potential of zakat in West Sumatra. There are still many muzzaki that cannot be folow up from BAZNAS, and the lack of human resources at BAZNAS West Sumatra Province.

Marketing Mix Strategy in Increasing Public Interest in the Field of Education

This study aims to analyze and describe in depth 1) Product in increasing public interest in education at MTs Ma’arif NU 2 Blitar and SMP Mambaus Sholihin Blitar. 2) Price in increasing public interest in education at MTs Ma’arif NU 2 Blitar and SMP Mambaus Sholihin Blitar. 3) Place in increasing public interest in education at MTs Ma’arif NU 2 Blitar and SMP Mambaus Sholihin Blitar. 4) Promotion in increasing public interest in education at MTs Ma’arif NU 2 Blitar and SMP Mambaus Sholihin Blitar. This study uses a qualitative approach, a type of case study with a multi-case design. Data collection techniques using in-depth interviews, participant observation and documentation. Data analysis starts from data conditioning, data presentation, verification and drawing conclusions. Data were analyzed from single case and cross case data. The results of the study show 1) Product as a marketing mix strategy in increasing public interest in education includes academic competence (guaranteed passing of madrasa exams and national exams), and Islamic boarding schools competence. 2) Price as a marketing mix strategy in increasing public interest in the field includes affordable financing, cross subsidies and scholarships. 3) Place as a marketing mix strategy in increasing public interest in education includes the location of madrasas within Islamic boarding schools. 4) Promotion as a marketing mix strategy in increasing public interest in education includes direct promotion from the guardians of students and students, electronic print media and social media. 5) Institutional performance as a marketing mix strategy in increasing public interest in education is an institution accredited A, magnificent buildings and complete facilities, performance of financial administration services that are friendly, accountable and fast, performance of food and drink services that are timely, nutritious, healthy, varied, and sufficient, the performance of clean and sufficient MCK services, the performance of security and comfort services, teachers and supervisors are parents of students. 6) Pray as a marketing mix strategy in increasing public interest in education is istighosah, other aurotans and spiritual teachers.

Three-dimensional printing of soft hydrogel electronics

Electronics based on hydrogels can have inherent similarities to biological tissue and are of potential use in biomedical applications. Ideally, such hydrogel electronics should offer customizable three-dimensional circuits, but making complex three-dimensional circuits encapsulated within a hydrogel matrix is challenging with existing materials and manufacturing methods. Here we report the three-dimensional printing of hydrogel electronics using a curable hydrogel-based supporting matrix and a stretchable silver–hydrogel ink. The supporting matrix has a yield stress fluid behaviour, so the shear force generated by a moving printer nozzle creates a temporary fluid-like state, allowing the accurate placement in the matrix of silver–hydrogel ink circuits and electronic components. After printing, the entire matrix and embedded circuitry can be cured at 60 °C to form soft (Young’s modulus of less than 5 kPa) and stretchable (elongation of around 18) monolithic hydrogel electronics, whereas the conductive ink exhibits a high conductivity of around 1.4 × 103 S cm−1. We use our three-dimensional printing approach to create strain sensors, inductors and biological electrodes.

3D printing of hydrogel electronics

3D printing of hydrogel electronics

Stabilization formation characterization of metal single droplet by pneumatic drop-on-demand

Metal single droplets are widely used in electronic packaging and flexible circuit printing. However, liquid metals are characterized by high density and interfacial tension, so that stable injection of single droplet occurs only in an extremely small printable region, which limits the application of metal droplets. In this study, based on a drop-on-demand pneumatic injection device, the evolutionary process and mechanism of metal droplet generation are analyzed through experiments and numerical simulations, the theoretical solution of the injection velocity is obtained, the printable region that can stably generate the single droplet dimensionless parameters Wej (Jet Weber number) and Z (1/Ohnesorge number) is plotted, and the prediction model of the single droplet dimensionless limit jet length is established. Results show that in the range 400 < Z < 1100, the printable region where single droplets can be generated is extremely narrow (1.3 < Wej < 2). When Wej < 1.3, the inertial force of the jet is not sufficient to overcome the interfacial capillary force, and no droplets can be generated. When Wej > 2, the inertial force of the jet is so large that satellite droplets are generated. The prediction results obtained by the prediction model of single droplet dimensionless limit jet length are consistent with the experimental results and can accurately predict whether a single droplet can be generated or not. The results can reveal the mechanism of stable generation of on-demand pneumatic metal droplets. Furthermore, the results can serve as theoretical references for the further development of on-demand pneumatic metal droplet injection technology.

A Comprehensive Review on Printed Electronics: A Technology Drift towards a Sustainable Future

Printable electronics is emerging as one of the fast-growing engineering fields with a higher degree of customization and reliability. Ironically, sustainable printing technology is essential because of the minimal waste to the environment. To move forward, we need to harness the fabrication technology with the potential to support traditional process. In this review, we have systematically discussed in detail the various manufacturing materials and processing technologies. The selection criteria for the assessment are conducted systematically on the manuscript published in the last 10 years (2012-2022) in peer-reviewed journals. We have discussed the various kinds of printable ink which are used for fabrication based on nanoparticles, nanosheets, nanowires, molecular formulation, and resin. The printing methods and technologies used for printing for each technology are also reviewed in detail. Despite the major development in printing technology some critical challenges needed to be addressed and critically assessed. One such challenge is the coffee ring effect, the possible methods to reduce the effect on modulating the ink environmental condition are also indicated. Finally, a summary of printable electronics for various applications across the diverse industrial manufacturing sector is presented.

Analysis of volatile organic components of organic solvents used in Bao'an District of Shenzhen

Objective: To understand the volatile organic components in the organic solvents used by enterprises in Baoan District, Shenzhen. Methods: From January to December 2020, a total of 541 organic solvent samples used by 86 companies were collected for volatile organic component analysis, and the main volatile components and high-risk occupational hazards in organic solvents used in different industries were analyzed. Results: A total of 201 volatile organic components were detected in 541 organic solvents. The top 5 components detected include xylene (29.76%, 116/541), toluene (21.81%, 118/541), methanol (20.70%, 112/541), n-hexane (14.79%, 80/541) and ethylbenzene (14.23%, 77/541). The detection rates of benzene, trichloroethylene, n-hexane, and 1, 2-dichloroethane, which were high-risk occupational hazards, were 2.40% (13/541), 3.70% (20/541), 14.79% (80/541), and 1.66% (9/541), respectively. The volatile components in organic solvents used in different industries was different. Benzene is more frequently detected in organic solvents used in the printing industry, trichloroethylene was more frequently detected in organic solvents used in the electronics industry, and n-hexane was more commonly found in organic solvents used in the electronics industry, printing and other industries, and 1, 2-dichloroethane has been more frequently detected in organic solvents used in the machinery industry. Conclusion: There are many types of organic solvents used by enterprises in Bao'an District, with complex components and differences in different industries.

Curvilinear soft electronics by micromolding of metal nanowires in capillaries.

Soft electronics using metal nanowires have attracted notable attention attributed to their high electrical conductivity and mechanical flexibility. However, high-resolution complex patterning of metal nanowires on curvilinear substrates remains a challenge. Here, a micromolding-based method is reported for scalable printing of metal nanowires, which enables complex and highly conductive patterns on soft curvilinear and uneven substrates with high resolution and uniformity. Printing resolution of 20 μm and conductivity of the printed patterns of ~6.3 × 106 S/m are achieved. Printing of grid structures with uniform thickness for transparent conductive electrodes (TCEs) and direct printing of pressure sensors on curved surfaces such as glove and contact lens are also realized. The printed hybrid soft TCEs and smart contact lens show promising applications in optoelectronic devices and personal health monitoring, respectively. This printing method can be extended to other nanomaterials for large-scale printing of high-performance soft electronics.

Shellac-paper composite as a green substrate for printed electronics

Printed electronic (PE) devices that sense and communicate data will become ubiquitous as the Internet of things continues to grow. Devices that are low cost and disposable will revolutionize areas such as smart packaging, but a major challenge in this field is the reliance on plastic substrates such as polyethylene terephthalate. Plastics discarded in landfills degrade to form micro- and nanoplastics that are hazardous to humans, animals, and aquatic systems. Replacing plastics with paper substrates is a greener approach due to the biodegradability, recyclability, low cost, and compatibility with roll-to-roll printing. However, the porous microstructure of paper promotes the wicking of functional inks, which adversely affects printability and electrical performance. Furthermore, truly sustainable PE must support the separation of electronic materials, particularly metallic inks, from the paper substrate at the end of life. This important step is necessary to avoid contamination of recycled paper and/or waste streams and enable the recovery of electronic materials. Here, we describe the use of shellac—a green and sustainable material—as a multifunctional component of green, paper-based PE. Shellac is a cost-effective biopolymer widely used as a protective coating due to its beneficial properties (hardness, UV resistance, and high moisture- and gas-barrier properties); nonetheless, shellac has not been significantly explored in PE. We show that shellac has great potential in green PE by using it to coat paper substrates to create planarized, printable surfaces. At the end of life, shellac acts as a sacrificial layer. Immersing the printed device in methanol dissolves the shellac layer, enabling the separation of PE materials from the paper substrate.