Search

Highlights Naturally crosslinked carbonaceous liquid metal aqueous printable ink mediated by biopolymers. E-textile with conductivity, stability, wearability, and aesthetic characteristics. Multi-applications in health monitoring, pressure sensing, and energy harvesting.

Summary: A dual‐band, wearable coplanar microstrip patch antenna (CPW) integrated with electromagnetic bandgap structure (EBG) to operate dual wireless bands at 2.48 GHz industrial, scientific, and medical band (ISM) and 5.2 GHz WLAN. The proposed textile wearable antenna and EBG structure are screen‐printed using silver conductive ink on the cotton polyester substrate (εr = 1.6) for flexible wearable applications. A 3 × 3 EBG array is realized by a concentric square patch surrounded by the annular square ring to reduce back radiation and increase the forward gain and front‐back ratio. The proposed EBG‐backed antenna, compared with the conventional CPW‐fed antenna, improves forward gain from 2.18 to 6.59 dB at 2.48 GHz and 3.5 to 7.03 dB at 5.2 GHz. Moreover, the EBG array is used to isolate the human body from the antenna and reduces the specific absorption rate (SAR). The antenna is performed with a human phantom tissue model, which exhibits a specific absorption rate of 0.12 W/kg, and 0.260 W/kg for 1 g tissue at 2.48 GHz and 5.2 GHz, respectively. [ABSTRACT FROM AUTHOR]

We developed a novel method to minimize the bezel of flexible displays through backside bonding of a chip on film, resulting in the bezel width of less than 500 μm as compared to 1000 μm of conventional displays. The metal embedded in polyimide (MEP) layer is placed between the first and second polyimide (PI) substrates and connected to the metal lines of the backplane via the MEP contact (M‐CNT) hole. Subsequently, the nonconductive film (NCF) bonding and intense pulsed light sintering are performed using conductive ink. Conductive ink as the interconnect material capable of low‐temperature sintering is applied to avert thermal degradation and crack. At a high temperature (65°C) and humidity (90% relative humidity), the contact resistance was a drivable level for the display after 240 h. The normalized strain in the M‐CNT hole and MEP area were less than 0.4, indicating the absence of cracks during the NCF bonding. These results demonstrated that the backside bonding method was suitable for extremely narrow bezels of the next‐generation flexible displays. [ABSTRACT FROM AUTHOR]

In recent years, additive manufacturing tools, such as 3D printing, has gained enormous attention in biomedical engineering for developing ionotropic devices, flexible electronics, skin‐electronic interfaces, and wearable sensors with extremely high precision and sensing accuracy. Such printed bioelectronics are innovative and can be used as multi‐stimuli response platforms for human health monitoring and disease diagnosis. This review systematically discusses the past, present, and future of the various printable and stretchable soft bioelectronics for precision medicine. The potential of various naturally and chemically derived conductive biopolymer inks and their nanocomposites with tunable physico‐chemical properties is also highlighted, which is crucial for bioelectronics fabrication. Then, the design strategies of various printable sensors for human body sensing are summarized. In conclusion, the perspectives on the future advanced bioelectronics are described, which will be helpful, particularly in the field of nano/biomedicine. An in‐depth knowledge of materials design to functional aspects of printable bioelectronics is demonstrated, with an aim to accelerate the development of next‐generation wearables. [ABSTRACT FROM AUTHOR]

Flexible textile antennas are important for wireless communication within the expansion of 5G and the Internet of Things (IoT), as it allows for their integration in daily life objects. However, achieving these functionalities in textiles is challenging because of limitations in the electronic performance, flexibility with scalable fabrication process. This paper presents two flexible textile antennas for wearable and non‐ wearable devices compatible with 5G technology created by printing highly conductive silver nanoparticle inks. Two textile substrates are explored, as the dielectric component, a 3D polyester, and a natural origin fabric, burel. The processes used are cost‐effective and scalable, with the antennas designed to operate at 3–3.5 GHz, maintaining their return loss performance even under bending deformation and washing cycles. By transferring the optimized devices into clothes and wall covering, a detailed analysis with experimental measurements of the textile‐based antenna for different operation scenarios is introduced. The work highlights the suitability of these antennas for wearable applications and their alignment with green wireless technologies, contributing to the advancement of sustainable wireless communication systems. [ABSTRACT FROM AUTHOR]

Highlights: Naturally crosslinked carbonaceous liquid metal aqueous printable ink mediated by biopolymers. E-textile with conductivity, stability, wearability, and aesthetic characteristics. Multi-applications in health monitoring, pressure sensing, and energy harvesting. Achieving flexible electronics with comfort and durability comparable to traditional textiles is one of the ultimate pursuits of smart wearables. Ink printing is desirable for e-textile development using a simple and inexpensive process. However, fabricating high-performance atop textiles with good dispersity, stability, biocompatibility, and wearability for high-resolution, large-scale manufacturing, and practical applications has remained challenging. Here, water-based multi-walled carbon nanotubes (MWCNTs)-decorated liquid metal (LM) inks are proposed with carbonaceous gallium–indium micro-nanostructure. With the assistance of biopolymers, the sodium alginate-encapsulated LM droplets contain high carboxyl groups which non-covalently crosslink with silk sericin-mediated MWCNTs. E-textile can be prepared subsequently via printing technique and natural waterproof triboelectric coating, enabling good flexibility, hydrophilicity, breathability, wearability, biocompatibility, conductivity, stability, and excellent versatility, without any artificial chemicals. The obtained e-textile can be used in various applications with designable patterns and circuits. Multi-sensing applications of recognizing complex human motions, breathing, phonation, and pressure distribution are demonstrated with repeatable and reliable signals. Self-powered and energy-harvesting capabilities are also presented by driving electronic devices and lighting LEDs. As proof of concept, this work provides new opportunities in a scalable and sustainable way to develop novel wearable electronics and smart clothing for future commercial applications. [ABSTRACT FROM AUTHOR]

A disposable voltammetric immunosensor was developed to measure breast cancer biomarker 15-3 (CA 15-3) in human saliva and serum samples. Screen-printed paper-based electrodes (f-SPE) previously fabricated by our research group using homemade conductive inks were used as transducers, which were later modified only with gold nanoparticles to immobilize anti-CA 15-3 antibodies. The sensor was operated using antigen–antibody interactions in conjunction with a redox species (ferrocyanide potassium) for the indirect determination of the CA 15-3 antigen. The device characterization involved atomic force microscopy (AFM) and electrochemical analysis. Optimization of the construction and response of the immunosensor was achieved at incubation times of 6 h for anti-CA 15-3, 1 h for bovine serum albumin, and 1 h for interaction with CA 15-3. The sensor displays a linear range between 2 and 16 U/mL, with a sensitivity of 0.012 μA/U mL−1, a limit of detection (LOD) of 0.56 U/mL, and a limit of quantification (LOQ) of 1.88 U/mL. The interfering substances minimally affected the signal, with 4.94% response variation, and the reproducibility of the immunosensor demonstrated a relative standard deviation (RSD) of 5.65%. The sensor successfully determined the CA 15-3 concentration in human serum and saliva, demonstrating its potential for clinical analysis. [ABSTRACT FROM AUTHOR]

Electronics and mechatronics waste is an exponentially increasing environmental issue, especially for wearable devices, due to their widespread diffusion into society and short life cycle. To promote their enormous benefits (e.g., in assisting visually impaired individuals) in a sustainable way, biobased and/or biodegradable organic materials should be used instead of traditional components. This manuscript presents a multidisciplinary approach, which bridges materials science and mechatronics, to propose the first ECO‐friendly wearable vibroTACtile device (Eco‐Tac). The design of Eco‐Tac includes integration on a cotton t‐shirt through a novel biodegradable conductive ink forming electrical tracks, a flexible commercially available solar panel, and the vibrotactile haptic device itself. The ink comprises a green solvent, anisole, a soft polybutylene adipate terephthalate biodegradable binder, and conductive nanocarbon materials. The device case is a biodegradable biocomposite. As such, the feasibility of using a sustainable energy source to supply power to the device and the possibility of using biodegradable materials in its manufacturing are demonstrated. An experiment with 20 blindfolded subjects is conducted, reporting the device's potential for assistance in manipulation tasks. Overall, the results of this work represent the first significant step toward the creation of wearable and sustainable haptic devices with green electronics and mechatronics approaches. [ABSTRACT FROM AUTHOR]

Additive manufacturing of ceramics has attracted large interest due to its unique ability to rapidly prototype, low cost, and increased geometric complexity. Material extrusion technique is often considered for processing and shaping fine and dense ceramic structures because of the high solid loading in ink. In this work, 8 mol.% yttria-stabilized zirconia ink with 70 wt% ceramic loadings was prepared to print zirconia samples in horizontal and vertical directions, following two different filament orientations: 0/90° and ±45°. The study's main objective was to evaluate printing design influences on mechanical properties. This was assessed through flexural testing and digital image correlation analysis. Experimental findings showed that samples printed horizontally with ±45° filament orientation displayed the highest strength. A detailed inspection of fracture surfaces revealed that printing defects were the critical failure location sites formed after sintering and intimately related to printing design issues. After that, a conductive sensor was integrated into the surfaces of 3D-printed specimens by screen-printing silver-based conductive ink to analyze the structural health of zirconia samples. The sensing capabilities of printed conductive patterns were investigated using the four-point bending tests. The results demonstrated that the electrical resistance of the printed silver patterns increased as the applied load on zirconia substrates rose. It indicates that hybrid material extrusion and screen printing techniques are favored ways to manufacture sensors for structural detection of advanced 3D-printed ceramics. [ABSTRACT FROM AUTHOR]

A stretchable electronic facial mask (SEFM) for skin electroporation by transdermal drug delivery is introduced. The SEFM exhibits characteristics of reusability, water‐resistant, low cost, and portability. To achieve these objectives while maintaining satisfactory mechanical and electrical performance of the device, two main areas are innovated: (1) Grinding and doping modification of conductive ink to enhance its adhesion to silicone and increase conductivity through material research, as well as mechanical structure design for stretching stability of conductive ink electrodes. (2) Doping modification of high‐temperature vulcanizes silicone to address the issue of increased resistance during encapsulation due to the swell of conductive ink. The SEFM designed with these innovations, is validated in rat experiments, demonstrating a 3–4 times increase in drug intake compared to the control group without skin electroporation. Safety is confirmed, and the promotion of niacinamide drug delivery is verified in human volunteers. The materials‐modified conductive ink and conductive silicone proposed in SEFM can be employed in other flexible wearable devices, and this platform has the potential for future integration of additional components to achieve expanded functionality and productization. [ABSTRACT FROM AUTHOR]

Photo‐mediated synthesis wielding localized surface plasmon resonance (LSPR) of nanoscale metal is widely applied to sculpt silver (Ag) nanocrystals with controllable dimensions and morphologies. However, this photo‐mediated strategy remains underutilized owing to low efficiency and inferior quality in conventional batch reactors. Here, the effective synthesis of Ag nanocrystals is demonstrated via flow reactors and elucidates the photo‐mediated anisotropic growth mechanism. The investigation reveals that the intersection between excitation wavelengths and LSPR of Ag nanocrystals is a prerequisite for their growth. The final morphology is highly correlated with excitation wavelengths, which modulate the redox potential (reaction barrier) of Ag nanocrystals featuring distinct defective structures. Thus, by utilizing tandem‐connected flow reactors, size‐controllable Ag nanoplates can be yielded in a highly efficient cascade growth manner. In addition, composite conductive ink (submicron/nano‐Ag particles) is employed to create high‐performance flexible transparent electrodes. A sixfold conductivity enhancement especially under low sintering temperature (<80 °C), along with superior transmittance (over 90%), and distinguished cyclic durability (negligible resistance change over 1000 cycles) are achieved simultaneously. The study not only establishes comprehensive insights into the acquisition of well‐defined Ag nanocrystals in flow reactors but also ushers in enormous feasibility toward high‐performance and cost‐effective flexible electronics. [ABSTRACT FROM AUTHOR]

All inkjet‐printed thermal sensors are manufactured based on a metal–insulator–metal (MIM) interface or capacitor architecture, for the adapted device size ranging from 16 to 36 mm2 active area. Two different material inks, namely a nanoparticle conductive silver ink and an inorganic‐polymer‐based hybrid insulator ink, are applied layer by layer on a thin flexible polyimide substrate, for developing the printed MIM devices. To ensure the desired electronic conductivity and insulation from the layers, the manufacturing process steps and parameters are tuned, accordingly. The results show that the inkjet‐printed MIM devices could constitute up to 15 μm thickness and demonstrate average detection of a change in electrical capacitance ranging from 20 to 100 pF, when the temperature is varied between 100 and 300 °C. The investigations also summarize that the change in the electrical response is enough to detect an increment of 50 °C. The printed sensors also display high operational stability and repeatability, when subjected to thermal cycling. [ABSTRACT FROM AUTHOR]

Stretchable strain sensors are widely used in the fields of wearable devices, soft robotics, healthcare monitoring, and more. Despite tremendous efforts, strain sensors capable of detecting large‐scale soil deformation for urban geological hazard prevention have not yet been demonstrated. In this paper, a soft strain sensor of a highly stretchable Ecoflex‐0030 elastomeric matrix with microchannel‐confined environmentally benign conductive Chinese ink as the liquid‐state strain‐sensitive material that can reliably detect a wide range of working strain up to 300% is demonstrated. The sensor exhibits a negligible hysteresis error of 2.1%, with a considerably good gauge factor of 1.95. The sensor performance is evaluated under both creep and cyclic loading tests, indicating superior stability (0.65% fluctuation), and repeatability (0.28% variation in 1000 cycles), even under a lower underground environment temperature of 18°C. As a proof‐of‐concept demonstration, a liquid‐state strain sensor array with a strain amplification mechanism capable of accurately monitoring the formation of various underground cavities and providing timely demanded information for early warning of catastrophic road collapse is demonstrated and verified by the computer vision‐based particle image velocimetry (PIV) method. [ABSTRACT FROM AUTHOR]

Non-enzymatic screen-printed chemiresistive interdigitated electrodes (SPCIE) were designed and fabricated using a low-cost screen-printing method for detection of the glucose. The interdigitated electrodes (IDE) pattern was printed using conductive graphene ink on the glossy surface of the photo paper. The proposed glossy photo paper-based SPCIE are functionalized with multi-walled carbon nanotubes-zinc oxide (MWCNTs-ZnO) nanofibers to create the chemiresistive matrix. Further, to bind these nanofibers with the graphene electrode surface, we have used the green synthesized silver nanoparticles (AgNPs) with banana flower stem fluid (BFSF) as a binder solution. AgNPs with BFSF form the conductive porous natural binder layer (CPNBL). It does not allow to increase the resistivity of the deposited material on graphene electrodes and also keeps the nanofibers intact with paper-based SPCIE. The synthesized material of MWCNT-ZnO nanofibers and green synthesized AgNPs with BFSF as a binder were characterized by Ultraviolet-visible spectroscopy (UV–vis), scanning electron microscope (SEM), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The amperometric measurements were performed on the proposed SPCIE sensor to detect the glucose sample directly. The innovative paper-based SPCIE glucose sensor exhibits a linear corelation between current measurements and glucose concentration in the range between 45.22 μ m and 20 mm, with a regression coefficient (R 2) of 0.9902 and a lower limit of detection (LoD) of 45.22 μ m (n = 5). The sensitivity of the developed SPCIE sensor was 2178.57 μ AmM−1cm−2, and the sensor's response time determined was approximately equal to 18 s. The proposed sensor was also tested for real blood serum sample, and relative standard deviation (RSD) was found equal to 2.95%. [ABSTRACT FROM AUTHOR]

A flexible extra broadband metamaterial absorber (MMA) stacked with five layers working at 2 GHz–40 GHz is investigated. Each layer is composed of polyvinyl chloride (PVC), polyimide (PI), and a frequency selective surface (FSS), which is printed on PI using conductive ink. To investigate this absorber, both one-dimensional analogous circuit analysis and three-dimensional full-wave simulation based on a physical model are provided. Various crucial electromagnetic properties, such as absorption, effective impedance, complex permittivity and permeability, electric current distribution and magnetic field distribution at resonant peak points, are studied in detail. Analysis shows that the working frequency of this absorber covers entire S, C, X, Ku, K and Ka bands with a minimum thickness of 0.098 λ max (λ max is the maximum wavelength in the absorption band), and the fractional bandwidth (FBW) reaches 181.1%. Moreover, the reflection coefficient is less than −10 dB at 1.998 GHz–40.056 GHz at normal incidence, and the absorptivity of the plane wave is greater than 80% when the incident angle is smaller than 50°. Furthermore, the proposed absorber is experimentally validated, and the experimental results show good agreement with the simulation results, which demonstrates the potential applicability of this absorber at 2 GHz–40 GHz. [ABSTRACT FROM AUTHOR]

Human exploratory missions to Moon or Mars are considered the next steps in human space exploration. Such activities result in the exposure of humans to the space environment for long time, especially under the constraints of orbital dynamics as with increasing distances from earth quick return possibilities are ruled out. Crews on these kinds of missions must be self-sustaining in medical treatments, as environmental conditions in space, such as the influence of altered gravity, radiation or isolation, raise health issues. Therefore, astronauts may use the here presented Handheld Bioprinter as part of the first-aid strategy for in situ wound treatment. The device consists of a handle capable of holding an exchangeable "Ink Printing Unit" containing two separate gel-like components (Bioink and Crosslinker), which are extruded during a printing process through a nozzle and form a skin-cell containing bioink band-aid. For ISS experiments cell simulants were used, as in-space experiments first demonstrated the general feasibility of handheld bioprinting under space conditions. On-ground human skin cells were mixed with the biogel, printed via the handheld bioprinter and cultivated, to demonstrate the overall feasibility of the "Bioprint FirstAid" technology. Concluding results were that a mobile, handheld tool like the bioprinter shows good applicability and offers a possibility of in situ wound treatment for in-space applications. The "Bioprint FirstAid" project was coordinated by the German Space Agency at the German Aerospace Center (DLR) in Bonn and funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK). • Handheld Bioprinter offers possibility for in-situ wound treatment in future in-space applications • Human skin cells proliferate in biogels after printing with handheld bioprinter • The customizable Ink-printing unit and nozzle can be tailored to specific printing demands • Bioprinter device has low susceptibility to failure, has a robust design, no electronics, and maintenance-free mechanics • German Astronaut Matthias Maurer conducted the Bioprinting experiment successfully on board the ISS [ABSTRACT FROM AUTHOR]

Printable silver inks are increasingly used in various electronic devices due to their versatility and applicability. However, silver nanoparticle-based conductive inks can cause blockage of inkjet printer nozzles due to aggregation and settlement. In the present study, the properties of printed silver conductive inks (AgNPs) produced by a conventional method and in-situ method are compared. The effect of the number of printing layers and morphology of printed tracks fabricated by both methods was investigated. The results of energy-dispersive X-ray and X-ray diffraction analyses showed that the conventional method produced high-purity AgNPs compared to the in-situ synthesis method. Likewise, the conventional synthesis method exhibited 85% higher electrical conductivity than the in-situ synthesis method at 1 printing layer. However, comparable electrical conductivity was observed for 8 printed layers for both methods. In short, the in-situ method has the potential to produce conductive AgNPs patterns, although a high number of printed layers are required to increase the conductive path. This method may solve the issues of particle agglomeration and sedimentation, which can block the nozzle during the printing process. [ABSTRACT FROM AUTHOR]

The field of printed organic electronics has not only made flexible devices accessible but also allows the production process toward a high throughput industrial scale. The current research involves the inkjet‐printing of an indium tin oxide‐free large‐area flexible hybrid electrode compose of a high conductivity organic layer (PEDOT: PSS) as a main electrode and inorganic silver nanoparticles‐based grid/film for the auxiliary electrode. The current bottleneck in the roll‐to‐roll production of printed electronics is the time required for the conductive inks to dry and sinter. Flash sintering is used to dry nano‐silver conductive ink to 77.6 m Ω □−1 sheet resistance in <20 ms, the quickest annealing procedure, without damaging flexible substrates. Flexible organic light‐emitting diodes (OLEDs) are created with a large active area (500 mm2) to demonstrate the efficacy of the flexible hybrid electrodes and the excellent bending stability (4 mm bending radius) of OLEDs. Maximum current efficiency of 19.58 cd A−1 and a maximum luminescence of 8708 cd m−2 at a low turn‐on voltage of 3.1 V for the small‐area (16 mm2) OLEDs are achieved. This method is promising for reducing indium consumption and paving the way for creating new high throughout hybrid electrodes for large‐area flexible printed electronics. [ABSTRACT FROM AUTHOR]

A new conductive ink based on the addition of carbon black to a poly(vinyl alcohol) matrix is developed and investigated for electrochemical sensing and biosensing applications. The produced devices were characterized using morphological and electrochemical techniques and modified with Pd nanoparticles to enhance electrical conductivity and reaction kinetics. With the aid of chemometrics, the parameters for metal deposition were investigated and the sensor was applied to the determination of Parkinson's disease biomarkers, specifically epinephrine and α-synuclein. A linear behavior was obtained in the range 0.75 to 100 μmol L-1 of the neurotransmitter, and the device displayed a limit of detection (LOD) of 0.051 μmol L-1. The three-electrode system was then tested using samples of synthetic cerebrospinal fluid. Afterward, the device was modified with specific antibodies to quantify α-synuclein using electrochemical impedance spectroscopy. In phosphate buffer, a linear range was obtained for α-synuclein concentrations from 1.5 to 15 μg mL-1, with a calculated LOD of 0.13 μg mL-1. The proposed immunosensor was also applied to blood serum samples, and, in this case, the linear range was observed from 6.0 to 100.5 μg mL-1 of α-synuclein, with a LOD = 1.3 µg mL-1. Both linear curves attend the range for the real diagnosis, demonstrating its potential application to complex matrices. [ABSTRACT FROM AUTHOR]

Research progress in the field of synthesis of graphene-like nanosheets has been expeditiously growing in the recent years because of their incredible properties in various fields offered by these two-dimensional nanostructures. Nano order thick graphitic flakes, one of the forms of graphene, can be used for many applications such as conductive inks, supercapacitors, nanofluids, gas sensing, etc. Synthesis of graphene flakes definitely the way to reach bulk quantity production. Preparation of stack layer graphene-like nanosheets from industrial waste carbon flake is important for scalable production at a low cost and societal uses. Our novel work surmised the fabrication of Nano order thick graphitic flakes from industrial waste using the modified hummer's method. The basic morphological characteristics have been examined by X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Gas sensor was prepared by depositing a thin film on a figure-type interdicted electrode epoxy substrate. The sensing behavior was detected by monitoring the change in resistance after hydrogen gas exposure using a computer control indigenously developed hydrogen gas sensing unit. • This work presents novel synthesis of Nano order thick graphene-like nanosheets from industrial waste using hummer's method. • The qualitative and quantitative analysis of synthesize nanosheets have done by characterized physicochemical properties. • The synthesize nanosheets based chemiresistor type gas sensor was prepared and tested for hydrogen gas. • The sensor shows the faster response and higher sensitivity over a long period toward hydrogen gas at room temperature. [ABSTRACT FROM AUTHOR]

In this study, a screen-printed electrode (SPE) for nitrite (NO2 -) sensing was fabricated through an inkjet printing technique using a commercial printer machine and preparing an ink composite solution containing graphene oxide (GO) and poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) as conductive materials. The optimum ink materials for SPE fabrication comprised GO and PEDOT:PSS with binders that resemble the viscosity of commercial ink. The surface topography of the fabricated SPE, which was characterized using scanning electron microscopy and atomic force microscopy, showed a smoother surface compared to the commercial screen-printed carbon electrode, with conductive ink materials deposited primarily from GO/PEDOT:PSS composites. This NO2 - sensor exhibited a linear response at the concentration range of 50-1000 µM, with limit of detection and limit of quantification as 25 and 50 µM, respectively. In addition, the stability, reproducibility, and selectivity of this sensor presented acceptable values in the analytical range. Furthermore, the performance of this sensor was compared with that of a spectrophotometry technique using synthetic water samples, and the results revealed its good analytical recovery at a confidence interval of 95%. Thus, our sensor based on SPE-modified GO/PEDOT:PSS, fabricated via the inkjet printing technique, can be potentially applied in monitoring NO2 - concentration in real samples. [ABSTRACT FROM AUTHOR]

This work developed a conductive ink composed of carbonaceous material for printing electrochemical sensors. The optimized ink comprises graphite, carbon black, and nail polish, respectively (35.3:11.7:53%), as well as acetone as a solvent. The proportion was optimized with consideration of the binder's solubilization, the ink's suitability for the screen-printing process, and lower electrical resistance. The materials used, and the resulting ink, were analyzed by way of Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The charge transfer resistance (Rct) obtained was 0.348 kΩ. The conductive ink was used to print an electrode on a PET substrate, and a flexible and disposable electrode was obtained. The electroactive area obtained was 13.7 cm2, which was calculated by the Randles-Sevcik equation. The applicability of the device was demonstrated with a redox probe, providing a sensitivity of 0.02 µ A L mmol−1. The conductive ink has adequate homogeneity for producing electrodes using the screen-printing technique, with a low estimated production cost of $ 0.09 mL−1. [ABSTRACT FROM AUTHOR]

Aerosol jet printing (AJP) is a new non-contact direct writing technique designed to achieve precise and intricate patterns on various substrates. Specifically, the pneumatic AJP process breaks down the ink into fine particles, significantly reducing the risk of nozzle clogging and rendering it highly advantageous for industrial applications. This paper focuses on the optimization of the line electrode formation process using soluble silver clusters as the conductive ink, along with the aerosol formation procedure. The main parameters of the AJP process, namely sheath flow rate, atomizer flow rate, and dispensing speed, were identified and examined for their influence on line width and resistivity. Through this analysis, an operability window, including optimized conditions for printing high-quality lines using the AJP process, was established, along with a regression equation enabling the statistical estimation of line width. In summary, the outcomes of this investigation underscore the feasibility of an integrated printing system capable of precision control over line width, achieved through the optimization of AJP process parameters. Furthermore, it was established that pneumatic AJP offers robust process stability. The practical applicability of the proposed optimization techniques was assessed, highlighting their potential utilization in electrode formation processes within the electronic and display industry. [ABSTRACT FROM AUTHOR]

A flexible printing electronical membrane is an electron equipment made by precisely spraying conductive metal ink such as silver on a soft membrane substrate. With its advantages of light weight and flexibility, it can adapt to changing working environments and is widely used in aerospace, wearable electronics and other fields. Nevertheless, during the manufacturing preparation of roll-to-roll printing membranes, the high-speed movement of printing electronical membranes under tension is affected by the impact of hot air from the drying oven and the electrostatic interference generated by friction in transmission, which restricts the overprint accuracy and preparation velocity of flexible electronical membranes. To address this issue, the nonlinear forced vibrational characteristics of a traveling flexible printing electronical membrane on temperature coupling subjected to nonlinear electrostatic force were investigated. The roll-to-roll printed intelligent RFID electron membrane is the research target. On the basis of the energy approach and the heat conduction equation considering the effect of deformation, the nonlinear vibrational equations of an axially traveling flexible printing electronical membrane coupled with temperature under the function of nonlinear electrostatical excitation force were derived. The Bubnov–Galerkin algorithm was applied to discretize the vibration partial differential equations; by making full use of the quartic Runge–Kutta numerical algorithm to calculate the approximate solution of equations, the phase portraits, Poincaré maps, time history diagrams, power spectra, and bifurcation plots of the nonlinear vibrations of the traveling printing electronical membrane were used to explore the effects of movement velocities, electrostatical field, and thermal coupling coefficients. The findings obtained the stable working domain and the divergence instability domain of the traveling flexible printing electronic membrane, which provided a theory fundamental for enhancing the stable craft of a printing electronical membrane. [ABSTRACT FROM AUTHOR]

Using a mixture of micro-copper and nano-silver in the production of screen-printed circuits has the potential to reduce material costs and cost variability. The fundamental premise of this study involved dispersing silver nanoparticles among the larger copper microparticles at selected ratios and subsequently sintering in order to establish their resultant electrical and physical performance. Commercial materials were mixed, printed, and sintered at two thermal regimes on fluorine-doped tin oxide (FTO)-coated glass substrate. The inclusion of 25% silver provided an appreciable reduction in electrical resistance from 4.21 Ω to 0.93 Ω, with further silver additions having less impact. The thermal regime used for sintering had a secondary impact on the final electrical performance. The addition of silver reduced the adhesion to the FTO substrate, with reduced film integrity. The results show that blending inks offers the advantage of enhancing material conductivity while simultaneously reducing costs, making it a compelling area for exploration and advancement in the field of electronics manufacturing. [ABSTRACT FROM AUTHOR]

In the context of advancing flexible electronic technologies, conductive ink has garnered significant scholarly interest. Wherein, metal-organic decomposition (MOD) ink composed of silver precursors, complexing agents, and volatile organic solvents, has been widely studied due to its advantages such as simple preparation, long shelf life, high jetting stability, and low-temperature processing. However, the volumetric reduction of MOD ink frequently surpasses 80%, which typically could lead to multiple voids and breaks in the conductive film, resulting in poor conductivity. Meanwhile, a high temperature of above 180 °C is usually required for the MOD ink to be converted into conductive film. Nevertheless, it is imperative for the ink to be deposited onto substrates at low temperatures. Herein, a low temperature conducting ink with multiple silver source precursors has been developed. The results show that after sintering at 100 °C for 40 min on a polyimide (PI) substrate, the resistivity of the silver film was 16.8 µ Ω cm, which is only ten times higher than that of bulk silver, and the silver film with good uniformity and conductivity can be formed. Defects, such as voids and cracks, are significantly reduced through the gradient decomposition of different silver source during the sintering process. The formula of ink and the effects of sintering temperature on the microstructure and electrical properties of silver ink thin films have been studied in details using XRD, SEM, EDX, and four-probe techniques. [ABSTRACT FROM AUTHOR]

Various new conductive materials with exceptional properties are utilized for the preparation of electronic devices. Achieving ultrahigh conductivity is crucial to attain excellent electrical performance. However, there is a lack of systematic research on the impact of conductor material thickness on device performance. Here, we investigate the effect of conductor thickness on power transmission and radiation in radio-frequency (RF) and microwave electronics based on MXene nanosheets material transmission lines and antennas. The MXene transmission line with thickness above the skin depth exhibits a good transmission coefficient of approximately −3 dB, and the realized gain of MXene antennas exceeds 2 dBi. Additionally, the signal transmission strength of MXene antenna with thickness above the skin depth is higher than 5-µm MXene antenna approximately 5.5 dB. Transmission lines and antennas made from MXene materials with thickness above the skin depth exhibit stable and reliable performance, which has significant implications for obtaining high-performance RF and microwave electronics based on new conductive materials. [ABSTRACT FROM AUTHOR]

This paper addresses the bandwidth limitations inherent in microstrip patch antennas, which are commonly employed in radar applications owing to their compact size and integration convenience. To overcome these limitations, this study explores the application of Prosopis Africana conductive ink-based thick film, an innovative and environmentally friendly material. Originating from the African mesquite tree, this ink exhibits high conductivity owing to its elevated carbon content, presenting a compelling solution for enhancing microstrip patch antenna bandwidth. The research entails thoroughly examining microstrip antenna design principles and associated challenges, followed by exploring the unique properties of Prosopis Africana conductive ink. A detailed methodology outlines the fabrication process of the ink-based thick layer or film on the substrate, with simulation and measurements employed to evaluate its impact on impedance matching and radiation characteristics. Emphasizing the eco-friendliness of Prosopis Africana conductive ink aligning with green electronics trends, the study showcases its potential for advancing wireless communication systems while reducing ecological footprints. Results demonstrate a substantial bandwidth improvement exceeding 1.85 GHz, a simulation |S11| return loss value of -16.19 dB, and achieved 84.5% radiation efficiency of the operating frequency at 9.5 GHz and a peak realized gain of 7.10 dB. Hence, integrating Prosopis Africana conductive ink-based thick film is a viable strategy for augmenting microstrip patch antenna bandwidth, rendering them more adept for radar applications. [ABSTRACT FROM AUTHOR]

In recent years, inkjet printing has emerged as a promising advanced fabrication technology in the field of electronics, offering remarkable advantages in terms of cost-effectiveness, design flexibility, and rapid prototyping. For these reasons, inkjet printing technology has been widely adopted in various applications, including printed circuit board fabrication, sensor development (e.g., temperature, humidity, and pressure sensing), and antenna and filter production, up to the microwave frequency range. The present paper is focused on the investigation of a methodology based on Monte Carlo simulations for quantitatively assessing the influence of fabrication tolerances on the performance of inkjet-printed microwave devices. In particular, the proposed methodology is applied to an inkjet-printed hairpin band pass filter specifically tailored for operation in the L band (i.e., from 1 GHz to 2 GHz). The initial design phase involved the use of computer aided design (CAD) software to optimize the geometric dimensions of the designed filter to closely match the desired performance specifications in terms of bandwidth, insertion loss, and return loss. Later, a Monte Carlo analysis was conducted to evaluate the propagation of tolerances in the fabrication process throughout the design and to estimate their effects on device performance. The fabrication process exploited the advanced capabilities of the Voltera inkjet printer, which was used to deposit a silver-based conductive ink on a commercial Rogers substrate. The device's performance was evaluated by comparing the simulated scattering parameters with those measured on the developed filter using a vector network analyzer (VNA), thus ensuring accurate validation of real-world performance. [ABSTRACT FROM AUTHOR]

Electronic waste carries energetic costs and an environmental burden rivaling that of plastic waste due to the rarity and toxicity of the heavy-metal components. Recyclable conductive composites are introduced for printed circuits formulated with polycaprolactone (PCL), conductive fillers, and enzyme/protectant nanoclusters. Circuits can be printed with flexibility (breaking strain ≈80%) and conductivity (≈2.1 × 104 S m-1 ). These composites are degraded at the end of life by immersion in warm water with programmable latency. Approximately 94% of the functional fillers can be recycled and reused with similar device performance. The printed circuits remain functional and degradable after shelf storage for at least 7 months at room temperature and one month of continuous operation under electrical voltage. The present studies provide composite design toward recyclable and easily disposable printed electronics for applications such as wearable electronics, biosensors, and soft robotics.

The generation of electronic waste (e‐waste) poses a significant environmental challenge, necessitating strategies to extend electronics' lifespan and incorporate eco‐friendly materials to enable their rapid degradation after disposal. Foldable electronics utilizing eco‐friendly materials offer enhanced durability during operation and degradability at the end of their life cycle. However, ensuring robust physical adhesion between electrodes/circuits and substrates during the folding process remains a challenge, leading to interface delamination and electronic failure. In this study, electrohydrodynamic (EHD) printing is employed as a cost‐effective method to fabricate the eco‐friendly foldable electronics by printing PEDOT:PSS/graphene composite circuits onto polyvinyl alcohol (PVA) films. The morphology and electrical properties of the printed patterns using inks with varying graphene and PEDOT:PSS weight ratios under different printing conditions are investigated. The foldability of the printed electronics is demonstrated, showing minimal resistance variation and stable electronic response even after four folds (16 layers) and hundreds of folding and unfolding cycles. Additionally, the application of printed PEDOT:PSS/graphene circuit is presented as a resistive temperature sensor for monitoring body temperature and respiration behavior. Furthermore, the transient features and degradation of the PEDOT:PSS/graphene/PVA based foldable electronics are explored, highlighting the potential promise as transient electronics in reducing electronic waste. [ABSTRACT FROM AUTHOR]

As the market demand for products such as flexible displays, IoT devices, and healthcare devices increases, attention has been drawn to printed electronics by a roll-to-roll process that can continuously produce electronic products on flexible substrates using functional inks. In particular, printed patterns need to be uniform in terms of the line width and thickness, which requires uniform control of the contact pressure during the roll-to-roll process, in processes that require ultra-fine pattern printing such as thin-film transistors for flexible displays. Because the contact pressure is indirectly measured using load cells, the performance of the conventional contact pressure control method tends to deteriorate due to the occurrence of time-delay and magnitude errors. Using the transfer function between the actual contact pressure and load cell, the time-delay is measured and compensated. To achieve contact pressure uniformization, the individual drive cross-coupled control system with the time-delay compensation is proposed. [ABSTRACT FROM AUTHOR]

Highlights: We propose a broad range triboelectric sensor system employing elastic sponge and shielding layers, which can realize fast stiffness recognition within 1.0 s at a low cost. A novel algorithm is proposed for rapid stiffness identification by extracting signal characteristics, effectively reducing demand of computing resources. The proposed sensor system can identify the multi-layer stiffness structure of objects, enabling effective recognition of variable inclusions in soft objects with an accuracy of 99.7%. With the development of artificial intelligence, stiffness sensors are extensively utilized in various fields, and their integration with robots for automated palpation has gained significant attention. This study presents a broad range self-powered stiffness sensor based on the triboelectric nanogenerator (Stiff-TENG) for variable inclusions in soft objects detection. The Stiff-TENG employs a stacked structure comprising an indium tin oxide film, an elastic sponge, a fluorinated ethylene propylene film with a conductive ink electrode, and two acrylic pieces with a shielding layer. Through the decoupling method, the Stiff-TENG achieves stiffness detection of objects within 1.0 s. The output performance and characteristics of the TENG for different stiffness objects under 4 mm displacement are analyzed. The Stiff-TENG is successfully used to detect the heterogeneous stiffness structures, enabling effective recognition of variable inclusions in soft object, reaching a recognition accuracy of 99.7%. Furthermore, its adaptability makes it well-suited for the detection of pathological conditions within the human body, as pathological tissues often exhibit changes in the stiffness of internal organs. This research highlights the innovative applications of TENG and thereby showcases its immense potential in healthcare applications such as palpation which assesses pathological conditions based on organ stiffness. [ABSTRACT FROM AUTHOR]

The increasing interest in disposable electronics such as wearable patches, e‐textiles, and smart packaging, warns emergence of another man‐made disaster. A paradigm shift toward a more sustainable future through the development of soft material architectures that are robust and durable, but also degradable by external stimuli is proposed. Hydrogels, a class of soft polymers with exceptional properties, and high water content are rarely used as substrates, mainly due to lack of ink‐adhesion and rapid dehydration. Herein, photodegradable hydrogels are tailor‐made that are nondrying, robust, adhesive to ink, and permit triggerable degradation, making them suitable substrates for sustainable electronics. These hydrogels are prepared by reversible ionic crosslinking between sodium alginate and divalent cations (Ca2+) and light‐responsive crosslinking of poly(acrylamide) (PAAm) chains through synthesized ortho‐nitrobenzyl (ONB)‐based crosslinkers. By displacing the water molecules in the hydrogels by immersion in glycerol, the drying problem and printability of conductive ink are addressed. It is demonstrated that digital printing of a liquid metal (LM)‐based stretchable ink over the developed substrate, shows several body‐worn printed wearable sensors, and demonstrates their degradation and recycling of the expensive metals. This work lays the foundation for the use of hydrogels as promising substrates for the next generation of environmentally friendly electronics. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) show excellent catalytic activity and have been widely applied in diagnosis of diseases and tumors. However, current assay methods usually involve cumbersome configurations and complicated procedures, which inhibit their practical applications. Hence, a Cu–Ni MOF/carbon printed electrode (CPE)-based integrated electrochemical immunosensor was constructed for highly sensitive and efficient determination of carcinoembryonic antigen (CEA). First, highly conductive carbon ink was screen-printed onto a polyethylene terephthalate substrate to manufacture a CPE. Afterward, an aminated Cu-Ni MOF was prepared by a typical solvothermal strategy and modified on the CPE. Owing to its excellent peroxidase activity, the Cu–Ni MOF can catalytically oxidize hydroquinone using hydrogen peroxide, which greatly amplifies the peak current signal. Then the formation of an immune complex inhibited the catalytic activity of the MOF, thus enabling the quantitative determination of CEA content with a wide linear range of 0.5 pg mL−1–500 ng mL−1 and a low detection limit of 0.16 pg mL−1. Furthermore, the Cu–Ni MOF/CPE-based integrated portable electrochemical immunosensor also showed satisfactory performance in the detection of CEA in clinical serum samples with excellent accuracy, showing great potential for application in point-of-care disease diagnosis. [ABSTRACT FROM AUTHOR]

The monitoring of potassium ion (K+) levels in human sweat can provide valuable insights into electrolyte balance and muscle fatigue non-invasively. However, existing laboratory techniques for sweat testing are complex, while wearable sensors face limitations like drift, fouling and interference from ions such as Na+. This work develops printed electrodes using β-cyclodextrin functionalized reduced graphene oxide (β-CD-RGO) for selective K+ quantification in sweat. The β-CD prevents the aggregation of RGO sheets while also providing selective binding sites for K+ capture. Electrodes were fabricated by screen printing the β-CD-RGO ink onto conductive carbon substrates. Material characterization confirmed the successful functionalization of RGO with β-CD. Cyclic voltammetry (CV) showed enhanced electrochemical behavior for β-CD-RGO-printed electrodes compared with bare carbon and RGO. Sensor optimization resulted in a formulation with 30% β-CD-RGO loading. The printed electrodes were drop-casted with an ion-selective polyvinyl chloride (PVC) membrane. A linear range from 10 μM to 100 mM was obtained along with a sensitivity of 54.7 mV/decade. The sensor showed good reproducibility over 10 cycles in 10 mM KCl. Minimal interference from 100 mM Na+ and other common sweat constituents validated the sensor's selectivity. On-body trials were performed by mounting the printed electrodes on human subjects during exercise. The K+ levels measured in sweat were found to correlate well with serum analysis, demonstrating the sensor's ability for non-invasive electrolyte monitoring. Overall, the facile synthesis of stable β-CD-RGO inks enables the scalable fabrication of wearable sensors for sweat potassium detection. [ABSTRACT FROM AUTHOR]

Reliable measurements in structural health monitoring mean for the instrumentation to be set in perfect reproducible conditions. The solution described in this study consists of printing the sensors directly on the parts to be controlled. This method solves the reproducibility issue, limits human error, and can be used in confined or hazardous environments. This work was limited to eddy current testing, but the settings and conclusions are transposable to any non-destructive testing methods (ultrasounds, etc.). The first salve of tests was run to establish the best dielectric and conductive ink combination. The Dupont ink combination gave the best performances. Then, the dispenser- and the screen-printing methods were carried out to print flat spiral coils on flexible substrates. The resulting sensors were compared to flex-printed circuit boards (PCB-flex) using copper for the electrical circuit. The conductive ink methods were revealed to be just as efficient. The last stage of this work consisted of printing sensors on solid parts. For this, 20-turn spiral coils were printed on 3 mm thick stainless-steel plates. The permanent sensors showed good sensibility in the same range as the portative ones, demonstrating the method's feasibility. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel tactile sensor with a "fingerprint" design, named due to its spiral shape and dimensions of 3.80 mm × 3.80 mm. The sensor is duplicated in a four-by-four array containing 16 tactile sensors to form a "SkinCell" pad of approximately 45 mm by 29 mm. The SkinCell was fabricated using a custom-built microfabrication platform called the NeXus which contains additive deposition tools and several robotic systems. We used the NeXus' six-degrees-of-freedom robotic platform with two different inkjet printers to deposit a conductive silver ink sensor electrode as well as the organic piezoresistive polymer PEDOT:PSS-Poly (3,4-ethylene dioxythiophene)-poly(styrene sulfonate) of our tactile sensor. Printing deposition profiles of 100-micron- and 250-micron-thick layers were measured using microscopy. The resulting structure was sintered in an oven and laminated. The lamination consisted of two different sensor sheets placed back-to-back to create a half-Wheatstone-bridge configuration, doubling the sensitivity and accomplishing temperature compensation. The resulting sensor array was then sandwiched between two layers of silicone elastomer that had protrusions and inner cavities to concentrate stresses and strains and increase the detection resolution. Furthermore, the tactile sensor was characterized under static and dynamic force loading. Over 180,000 cycles of indentation were conducted to establish its durability and repeatability. The results demonstrate that the SkinCell has an average spatial resolution of 0.827 mm, an average sensitivity of 0.328 m Ω / Ω / N , expressed as the change in resistance per force in Newtons, an average sensitivity of 1.795 µV/N at a loading pressure of 2.365 PSI, and a dynamic response time constant of 63 ms which make it suitable for both large area skins and fingertip human–robot interaction applications. [ABSTRACT FROM AUTHOR]

Inkjet printing has emerged as a promising low‐cost and high‐performance method for manufacturing printing‐based devices. However, the development of optimized substrates for inkjet printing using novel materials is limited. In this study, a novel polymeric substrate optimized for flexible electronic devices is fabricated using thin‐film processing and phase inversion of polyethersulfone (PES). The PES film consists of two layers of pores; the upper layer has nano‐sized pores that filter the nanoparticles in the conductive ink and allow for high‐density aggregation on the substrate, while the lower layer contains micro‐scale pores that quickly absorb and drain the ink solvent. The two porous structures lead to higher conductivity and high‐resolution printed patterns by minimizing solvent lateral diffusion. Additionally, the PES printing substrate can undergo high‐temperature curing of metal nanoparticles, enabling high‐resolution pattern printing with low resistance. The PES substrate is highly transparent and flexible, allowing for the fabrication of various printed electronic patterns and the production of high‐performance flexible electronic devices. [ABSTRACT FROM AUTHOR]

Pulsed laser ablation can be used to repair misprinted patterns in printed electronics. The properties of the conductive ink varied with sintering temperature. This property variation significantly affected the ablation process. Thus, we compared the pulsed laser scanning ablation of dried Ag nanoparticle (NP) layers, which were sintered at 150 ℃, and sintered at 200 ℃ with quantitative evaluations. With higher thermal diffusion, the AgNP layer sintered at higher temperatures had more protruding Ag parts at the ablated line boundary. Ablation threshold fluence values of 264, 547, and 1370 mJ/cm2 were obtained for the Ag NP layers that were dried, sintered at 150 ℃, and sintered at 200 ℃ using D2-law fittings, respectively. For the ablation process, the increase in the protruding Ag parts and the increase in the ablation threshold fluence would be problematic. For the sintered AgNP layers, D2-law predicted the ablation threshold fluence quite well. The sintering temperature of the Ag NPs affects the ablation phenomenon by changing the surface morphology and physical properties of the pre-sintered layer. [ABSTRACT FROM AUTHOR]

Electrocardiogram (ECG) electrodes are important sensors for detecting heart disease whose performance determines the validity and accuracy of the collected original ECG signals. Due to the large drawbacks (e.g., allergy, shelf life) of traditional commercial gel electrodes, textile electrodes receive widespread attention for their excellent comfortability and breathability. This work demonstrated a dry electrode for ECG monitoring fabricated by screen printing silver/silver chloride (Ag/AgCl) conductive ink on ordinary polyester fabric. The results show that the screen-printed textile electrodes have good and stable electrical and electrochemical properties and excellent ECG signal acquisition performance. Furthermore, the resistance of the screen-printed textile electrode is maintained within 0.5 Ω/cm after 5000 bending cycles or 20 washing and drying cycles, exhibiting excellent flexibility and durability. This research provides favorable support for the design and preparation of flexible and wearable electrophysiological sensing platforms. [ABSTRACT FROM AUTHOR]

Despite advances in soft, sticker‐like electronics, few efforts have dealt with the challenge of electronic waste. Here, this is addressed by introducing an eco‐friendly conductive ink for thin‐film circuitry composed of silver flakes and a water‐based polyurethane dispersion. This ink uniquely combines high electrical conductivity (1.6 × 105 S m−1), high resolution digital printability, robust adhesion for microchip integration, mechanical resilience, and recyclability. Recycling is achieved with an ecologically‐friendly processing method to decompose the circuits into constituent elements and recover the conductive ink with a decrease of only 2.4% in conductivity. Moreover, adding liquid metal enables stretchability of up to 200% strain, although this introduces the need for more complex recycling steps. Finally, on‐skin electrophysiological monitoring biostickers along with a recyclable smart package with integrated sensors for monitoring safe storage of perishable foods are demonstrated. [ABSTRACT FROM AUTHOR]

In recent years, there has been a huge surge in interest in improving the efficiency of smart electronic and optoelectronic devices via the development of novel materials and printing technologies. Inkjet printing, known to deposit 'ink on demand', helps to reduce the consumption of materials. Printing inks on various substrates like paper, glass, and fabric is possible, generating flexible devices that include supercapacitors, sensors, and electrochromic devices. Newer inks being tested and used include formulations of carbon nanoparticles, photochromic dyes, conducting polymers, etc. Among the conducting polymers, PANI has been well researched. It can be synthesized and doped easily and allows for the easy formation of composite conductive inks. Doping and the addition of additives like metal salts, oxidants, and halide ions tune its electrical properties. PANI has a large specific capacitance and has been researched for its applications in supercapacitors. It has been used as a sensor for pH and humidity as well as a biosensor for sweat, blood, etc. The response is generated by a change in its electrical conductivity. This review paper presents an overview of the investigations on the formulation of the inks based on conductive polymers, mainly centered around PANI, and inkjet printing of its formulations for a variety of devices, including supercapacitors, sensors, electrochromic devices, and patterning on flexible substrates. It covers their performance characteristics and also presents a future perspective on inkjet printing technology for advanced electronic, optoelectronic, and other conductive-polymer-based devices. We believe this review provides a new direction for next-generation conductive-polymer-based devices for various applications. [ABSTRACT FROM AUTHOR]

The research community has witnessed an exceptional increase in exploring graphene related two-dimensional materials (GR2Ms) in many innovative applications and emerging technologies. However, simple, low-cost, sustainable, and eco-friendly methods to manufacture large quantities and high-quality GR2Ms still remain an unsolved challenge. To address limitations of conventional wet chemical-based exfoliation methods using graphite resources, the top-down irradiation approach has proven to be an ultrafast, effective, and environmentally friendly technology for scalable exfoliation, production, and processing of GR2Ms providing new properties for emerging applications. Significant advancements have been made for preparation of broad range of GR2Ms from graphite, such as graphene, graphene oxide, and reduced graphene oxide, and their doped, functionalized and modified forms over the past two decades, thanks to the availability of photon and ion irradiation techniques, such as microwave, infrared, ultraviolet, solar, x-ray, gamma, laser, and plasma. This review presents recent advances on the application of these various irradiation techniques and highlights their mechanism, differences in properties of prepared GR2Ms, and their advantages and disadvantages in comparison with other conventional methods. The review provides an insight into the irradiation strategies and their prospective applications to produce, at a large scale, low-cost, high-quality GR2Ms for practical applications in transparent electrodes, optoelectronic devices, sensors, supercapacitors, protective coatings, conductive inks, and composites. [ABSTRACT FROM AUTHOR]