Laser-scribed Graphene Research Articles

Laser-scribed graphene on polyetherimide substrate: an electrochemical sensor platform for forensic determination of xylazine in urine and beverage samples.

A laser-scribed graphene (LSG) device fabricated on polymeric polyetherimide (PEI) substrate is reportedfor sensitive electrochemical detection of xylazine (XLZ), a veterinary drug that has been associated with drug-facilitated crimes. Morphological characterization was made by scanning electron microscopy (SEM), demonstrating that the electrochemical device presents a highly porous carbonaceous structure. In addition, Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), wettability, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements were used to characterize the PEI-LSG material, which showed superior electroanalytical performance after a simple anodic treatment in an alkaline medium (applying 2V for 120s in 0.1mol L-1 NaOH solution). The electrochemical determination of XLZ was carried out using square wave voltammetry (SWV), which showed sensitivity and coefficient ofdetermination (R2) equal to 0.206 ± 0.008 A L mol-1cm-2 and 0.991, respectively. In addition, we obtained a low limit of detection (LOD) of 1.39 × 10-7mol L-1 with a linear response in the concentration range 5.0 to 200.0 × 10-6mol L-1. The PEI-LSG electrochemical sensor was applied to XLZ detection in commercial beverage and synthetic urine samples, providing recoveries between 96.0 and 114.8%. Collectively, our electrochemical sensor presents an easy method to manufacture reproducible (relative standard deviation (RSD) of 2.56%), low-cost ($0.12), and single-use (disposable) devices, which is a promising way for in-field determination of drug-facilitated sexual assaults and other relevant applications.

Self-reduction of bimetallic nanoparticles on flexible MXene-graphene electrodes for simultaneous detection of ascorbic acid, dopamine, and uric acid

Three-dimensional (3D) porous laser-scribed graphene (LSG) is a potential electrode material for flexible electrochemical sensors due to its high efficiency and low cost. However, the growth of nanoparticles usually depends on reducers or harsh conditions, which limit the application of flexible biosensors. To resolve this issue, 2D MXene nanosheets were applied to functionalize 3D LSG sheets with a C-O-Ti covalent crosslink and obtain an LSG-MXene hybrid scaffold. The shape-controlled Au-Pd bimetallic nanoparticles were synthesized on the surface of LSG-MXene by a self-reduction process at room temperature for 6 min to enhance its catalytic performance. As a proof of concept, the obtained hybrid nanocomposite was used to assess ascorbic acid (AA, 10–1600 μM), dopamine (DA, 12–240 μM), and uric acid (UA, 8–100, 200–800 μM). The fabricated sensor exhibited a low detection limit (S/N = 3) of 3 μM AA, 0.13 μM DA, and 1.47 μM UA. Furthermore, the Au-Pd/MXene/LSG was successfully applied to determine AA, DA, and UA in urine samples. Predictably, these outstanding performance sensors have great potential in flexible and wearable electronics.

A Carbon-Based Thermoacoustic Speaker With High Vocal Efficiency and Low Power Consumption

Improving vocal efficiency and reducing power consumption are indispensable conditions to promote the wider applications of thermoacoustic devices. In this work, three kinds of thermoacoustic speakers based on different carbon-based materials are investigated. An analytical thermoacoustic model is proposed. This analytical thermoacoustic model considers the effect of phase on the sound pressure (SP) amplitude to improve the accuracy. In addition, this analytical thermoacoustic model considers the input power distribution, has good convergence, and simplifies the calculation. Sample fabrication and material characterization of three thermoacoustic speakers are given. The measured vocal efficiencies are <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.52\times 10^{-{7}}$ </tex-math></inline-formula> %, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.32\times 10^{-{7}}$ </tex-math></inline-formula> %, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.22\times 10^{-{7}}$ </tex-math></inline-formula> % for reduced graphene oxide (RGO), multiwalled carbon nanotube (MWCNT), and laser scribed graphene (LSG) samples, respectively, whose corresponding highest SP levels (SPLs) are 65.24, 57.41, and 40.68 dB. The measured results show that the fabricated RGO speaker has lower power consumption and higher effective vocal efficiency than the other two loudspeakers due to its high crystal quality and additional heat exchanger nanofins. This will provide its potential application in the field of wearable electronic devices.

Beyond High-Voltage Capacitors: Supercapacitor Arrays Based on Laser-Scribed Subwavelength-Featured Graphene Patterns

Beyond High-Voltage Capacitors: Supercapacitor Arrays Based on Laser-Scribed Subwavelength-Featured Graphene Patterns

Laser‐Scribed Graphene–Polyaniline Microsupercapacitor for Internet‐of‐Things Applications

AbstractThe push toward smart technologies and the Internet‐of‐Things (IoT) demands the development of miniaturized energy storage devices. Herein, a facile and scalable strategy is presented, based on laser reduction of graphene oxide into graphene followed by electrodeposition of polyaniline (PANi), to fabricate a substrate‐free supercapacitor. The fabricated supercapacitor is part of a flexible multifunctional integrated system comprising a thin‐film humidity sensor, a resistor, and a near field communication (NFC) antenna for IoT‐linked wireless communication with a smartphone. The integrated sensory system shares laser‐scribed graphene (LSG) as the same electrode material for all the components (supercapacitor, sensor, resistor, and NFC antenna). The symmetric LSG‐PANi||LSG‐PANi supercapacitor with wireless charging capability exhibits a near record‐high energy density of 0.407 mW h cm−3, and excellent power density of 196 mW cm−3, along with an outstanding rate capability (enduring high rates of over 1 V s−1). As a humidity sensor, the device demonstrates high resistance changes from 2000 kΩ at 0% relative humidity (RH) to 497 kΩ at 100% RH (15 kΩ per RH%) with a sub‐second scale (0.87 s) response time. This research paves the way for limitless applications of IoT across a wide spectrum of fields from healthcare to chip‐based electronics to environmental monitoring.

3D-porous laser-scribed graphene decorated with overoxidized polypyrrole as an electrochemical sensing platform for dopamine

The authors present in this work, a novel, simple, and disposable electrochemical sensor for the detection of dopamine (DA). Indeed, the proposed sensing system is based on overoxidized polypyrrole (PPyox) modified laser scribed graphene electrode (LSGE). LSGEs were fabricated via direct laser-writing on polyimide (PI) sheets to produce a 3D-porous structure of graphene that offers a large conducting surface area. The morphology of the electrode surface was analyzed using scanning electron microscopy (SEM). The electrochemical behavior of the developed sensor was investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Compared to conventional screen-printed carbon electrodes, the results showed that the current responses of DA were drastically enhanced due to the excellent catalytic activity of the LSGE as well as the strong electrostatic attraction of the deposited PPyox film that enables a selective accumulation of DA into the sensor’s surface. Furthermore, this sensing strategy demonstrated outstanding adsorption features toward DA detection leading to the detection of subnanomolar levels via preconcentration at an open circuit potential (OCP) system. Under optimal conditions, two linear calibration plots were established in the range of 0.5 µM–10 µM at a close circuit potential and 10 nM–500 nM under 5 min of preconcentration at OCP with a lower limit of detection estimated to be 7 nM. The developed sensor demonstrated good selectivity, adaptability, and stability. As a result, it was effectively employed for the detection of DA in human blood serum and tap water samples, with satisfactory recovery values.

A Highly Sensitive Electrochemical Sensor for Cd2+ Detection Based on Prussian Blue-PEDOT-Loaded Laser-Scribed Graphene-Modified Glassy Carbon Electrode

Heavy metal ion pollution has had a serious influence on human health and the environment. Therefore, the monitoring of heavy metal ions is of great practical significance. In this work, we describe the development of an electrochemical sensor to detect cadmium (Cd2+) using a Prussian blue (PB), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT)-loaded laser-scribed graphene (LSG) nanocomposite-modified glassy carbon electrode (GCE). In this nanocomposite material, we successfully brought together the advantages of an extraordinarily large surface area. The accumulation of PB nanoparticles results in an efficient electrochemical sensor with high sensitivity and selectivity and fast detection ability, developed for the trace-level detection of Cd2+. Electrochemical features were explored via cyclic voltammetry (CV), whereas the stripping voltammetry behavior of modified electrodes was analyzed by utilizing differential pulse voltammetry. Compared with bare GCE, the LSG/PB-PEDOT/GCE modified electrode greatly increased the anodic stripping peak currents of Cd2+. Under the optimized conditions, the direct and facile detection of Cd2+ was achieved with a wide linear range (1 nM–10 µM) and a low LOD (0.85 nM).

Polyaniline Modified Laser-Scribed Graphene for High-Performance Microsupercapacitors

Here, we successfully synthesize polyaniline (PANI)-modified laser-scribed graphene (LSG) composite electrodes for high-performance microsupercapacitors (MSCs). The three-dimensional (3D) porous LSG is directly patterned on a transparent polyethersulfone (PES) film via one-step laser irradiation. PANI is then electrodeposited on the LSG conductive skeletons to obtain LSG/PANI hybrid electrodes. As expected, the fabricated LSG/PANI-40 based MSC offers an outstanding areal capacitance of 129.51 mF cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> , which is far larger than that of pure LSG-based MSC (0.58 mF cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> ). Therefore, this study demonstrates the significant application potential of LSG/PANI composite electrodes in high-performance energy storage devices.

3D printing stretchable core-shell laser scribed graphene conductive network for self-powered wearable devices

Graphene-based flexible electronics, particularly those with self-powered ability and stretchability, are greatly promising candidates in the applications of portable and wearable devices. However, complicated deformation of human body and harsh environment inevitably leads to the degradation of conductivity of wearable electronics due to the intrinsic brittleness and crack sensitivity of graphene. Herein, a metamaterial-inspired stretchable and stable conductive network fabricated by 3D printing polyether-ether-ketone (PEEK) and double-side laser scribing graphene (LSG) techniques is demonstrated, which is called LSGCN. The double-side LSG covers the outer surfaces of printed PEEK filaments and forms a special core-shell structure, and its conductivity is 2.72 times of traditional flat graphene. Moreover, the parametric design of LSGCN can increase the stretchability of the structure from 20% to 118%, while ensuring that the change rate of resistance is limited to 1.06 within the 60% strain range. Based on the triboelectric effect, we also demonstrate LSGCN-based self-powered devices, including wearable smart belts and human-computer interaction gloves. Particularly, the LSGCN glove integrates 21 interactive channels, and it can work as the input equipment to control the simulated calculator, display the slides and even play the 3D games. This hybrid-fabricating method of LSGCN provides a novel strategy to fabricate stretch-stable conductive structures for applications in bio-energy harvesting and self-powered sensing devices, which opens up a new avenue for the future Internet of Things.

Laser-scribed Graphene Electrodes Functionalized with Nafion/Fe3O4 Nanohybrids for the Ultrasensitive Detection of Neurotoxin Drug Clioquinol.

The analysis of pharmaceutical active ingredients plays an important role in quality control and clinical trials because they have a significant physiological effect on the human body even at low concentrations. Herein, a flexible three-electrode system using laser-scribed graphene (LSG) technology, which consists of Nafion/Fe3O4 nanohybrids immobilized on LSG as the working electrode and LSG counter and reference electrodes on a single polyimide film, is presented. A Nafion/Fe3O4/LSG electrode is constructed by drop coating a solution of Nafion/Fe3O4, which is electrostatically self-assembled between positively charged Fe3O4 and negatively charged Nafion on the LSG electrode and is used for the first time to determine a neurotoxicity drug (clioquinol; CQL) in biological samples. Owing to their porous 3D structure, an enriched surface area at the active edges and polar groups (OH, COOH, and −SO3H) in Nafion/Fe3O4/LSG electrodes resulted in excellent wettability to facilitate electrolyte diffusion, which gave ∼twofold enhancement in electrocatalytic activity over LSG electrodes. The experimental parameters affecting the analytical performance were investigated. The quantification of clioquinol on the Nafion/Fe3O4/LSG electrode surface was examined using differential pulse voltammetry and chronoamperometry techniques. The fabricated sensor displays preferable sensitivity (17.4 μA μM–1 cm–2), a wide linear range (1 nM to 100 μM), a very low detection limit (0.73 nM), and acceptable selectivity toward quantitative analysis of CQL. Furthermore, the reliability of the sensor was checked by CQL detection in spiked human blood serum and urine samples, and satisfactory recoveries were obtained.

A Portable Molecularly Imprinted Sensor for On-Site and Wireless Environmental Bisphenol A Monitoring.

The detection of pollutant traces in the public and environmental waters is essential for safety of the population. Bisphenol A (BPA) is a toxic chemical widely used for the production of food storage containers by plastic industries to increase the storage ability. However, the insertion of BPA in water medium leads to serious health risks. Therefore, the development of low-cost, practical, sensitive, and selective devices to monitor BPA levels on-site in the environment is highly needed. Herein, for the first time, we present a homemade portable potentiostat device integrated to a laser-scribed graphene (LSG) sensor for BPA detection as a practical environmental pollutant monitoring tool. Recently, there has been an increasing need regarding the development of graphene-based electrochemical transducers (e.g., electrodes) to obtain efficient biosensing platforms. LSG platform is combined with molecularly imprinted polymer (MIP) matrix. LSG electrodes were modified with gold nanostructures and PEDOT polymer electrodeposition to create a specific MIP biomimetic receptor for ultrasensitive BPA detection. The sensing device has a Bluetooth connection, wirelessly connected to a smartphone providing high sensitivity and sensitivity (LOD: 3.97 nM in a linear range of .01–10 µM) toward BPA. Two commercial bottled water samples, tap water, commercial milk, and baby formula samples have been used to validate the reliability of the portable sensor device.

Highly Stretchable and Self-Adhesive Elastomers Based on Polymer Chain Rearrangement for High-Performance Strain Sensors.

Polydimethylsiloxane (PDMS) has been widely used in many fields. However, the polymerization process of the siloxane chain is highly complex, and it is challenging to enhance the mechanical properties of PDMS elastomers significantly. We found that adding a small amount of polyoxyethylene lauryl ether (Brij-35) into siloxane polymers can result in B-PDMS elastomers with high tensile properties and strong adhesion. It is worth noting that this is the first study to improve the mechanical properties of PDMS using Brij-35. Here, we intensely studied a variety of process conditions that influence the cross-linking of PDMS, emphasizing the modification mechanism of the polymer chain. The hydroxyl groups in Brij-35 and the platinum catalyst in PDMS form a complex, which inhibits the cross-linking process of PDMS, not only forming a heterogeneous cross-linking network in the B-PDMS but also disentangling the strongly wound siloxane polymer chain, thereby rearranging the PDMS polymer chains. Furthermore, in order to prepare a strain sensor based on the B-PDMS elastomer under safe and convenient conditions, we prepared laser-scribed graphene powder (LSGP) by laser-scribing of graphene oxide (GO) films, and the LSGP and carbon nanotubes (CNTs) endowed the B-PDMS elastomers with excellent electrical properties. The sensor could firmly adhere to the skin and generate a high-quality response to a variety of human motions, and it could drive the robotic hand to grasp and lift objects accurately. The high-performance strain sensors based on B-PDMS have broad applications in medical sensing and biopotential measurement.

Laser In Situ Preparation of S-Doped Porous Graphene for Flexible Microsupercapacitors

In this work, a facile growing laser-scribed graphene (LSG) process is successfully demonstrated, which can pattern in situ sulfur (S)-doped porous graphene electrodes on a flexible sodium lignosulfonate (SLS)-coated polyethersulfone (PES) film. The typical microsupercapacitors (MSCs) based on S-doped porous graphene deliver an ultrahigh areal capacitance of 55.4 mF cm^&#x2212;2, and have good long-term cycle stability with 85.2&#x0025; capacitance retention after 10000 cycles. Moreover, these devices exhibit superb mechanical flexibility and outstanding modular integration capability. This novel fabrication approach can be extended to other heteroatom-doped electrode materials for application in high-performance energy storage devices.

'All In One' SARS-CoV-2 variant recognition platform: Machine learning-enabled point of care diagnostics

Point of care (PoC) devices are highly demanding to control current pandemic, originated from severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Though nucleic acid-based methods such as RT-PCR are widely available, they require sample preparation and long processing time. PoC diagnostic devices provide relatively faster and stable results. However they require further investigation to provide high accuracy and be adaptable for the new variants. In this study, laser-scribed graphene (LSG) sensors are coupled with gold nanoparticles (AuNPs) as stable promising biosensing platforms. Angiotensin Converting Enzyme 2 (ACE2), an enzymatic receptor, is chosen to be the biorecognition unit due to its high binding affinity towards spike proteins as a key-lock model. The sensor was integrated to a homemade and portable potentistat device, wirelessly connected to a smartphone having a customized application for easy operation. LODs of 5.14 and 2.09 ng/mL was achieved for S1 and S2 protein in the linear range of 1.0–200 ng/mL, respectively. Clinical study has been conducted with nasopharyngeal swabs from 63 patients having alpha (B.1.1.7), beta (B.1.351), delta (B.1.617.2) variants, patients without mutation and negative patients. A machine learning model was developed with accuracy of 99.37% for the identification of the SARS-Cov-2 variants under 1 min. With the increasing need for rapid and improved disease diagnosis and monitoring, the PoC platform proved its potential for real time monitoring by providing accurate and fast variant identification without any expertise and pre sample preparation, which is exactly what societies need in this time of pandemic.

Laser-scribed graphene sensors on nail polish with tunable composition for electrochemical detection of nitrite and glucose

Laser-induced graphene (LIG) techniques enable the direct laser writing or scribing of conductive graphene electrodes on insulative polymer substrates without complicated synthesis or fabrication processes. The precursors of LIG essentially determine its quality and applications in various fields including electrochemical devices. Here, we demonstrate that the widely used nail polish (NP) is a promising precursor of LIG, which can be converted into 3D porous graphene electrodes in air using a 405 nm laser engraving machine. The produced nail polish-based LIG (NP-LIG) electrodes possess high conductivity, good mechanical property, and tunable composition and electrochemical activity. These unique properties make NP-LIG a promising platform for developing cost-effective electrochemical sensing devices. A robust flexible electrochemical sensor of nitrite was therefore constructed on NP-LIG using chitosan as a sensing material, which shows a sensitive and selective response for the detection of nitrite with a calibration range of 2.0–1000 μM and a detection limit of 0.9 μM (S/N = 3). In addition, a non-enzymatic glucose electrochemical sensor was constructed by doping NP-LIG with copper ions (Cu2+/NP-LIG), suggesting the doping ability of NP-LIG by a simple mixing method.

Two-Beam Ultrafast Laser Scribing of Graphene Patterns with 90-nm Subdiffraction Feature Size

The fabrication of high-resolution laser-scribed graphene devices is crucial to achieving large surface areas and thus performance breakthroughs. However, since the investigation mainly focuses on the laser-induced reduction of graphene oxide, the single-beam scribing provides a tremendous challenge to realizing subdiffraction features of graphene patterns. Here, we present an innovative 2-beam laser scribing pathway for the fabrication of subdiffraction graphene patterns. First, an oxidation reaction of highly reduced graphene oxide can be controllably driven by irradiation of a 532-nm femtosecond laser beam. Based on the oxidation mechanism, a 2-beam laser scribing was performed on graphene oxide thin films, in which a doughnut-shaped 375-nm beam reduces graphene oxide and a spherical 532-nm ultrafast beam induces the oxidation of laser-reduced graphene oxide. The spherical beam turns the highly reduced graphene oxide (reduced by the doughnut-shaped beam) to an oxidized state, splitting the laser-scribed graphene oxide line into 2 subdiffraction featured segments and thus forming a laser-scribed graphene/oxidized laser-scribed graphene/laser-scribed graphene line. Through the adjustment of the oxidation beam power, the minimum linewidth of laser-scribed graphene was measured to be 90 nm. Next, we fabricated patterned supercapacitor electrodes containing parallel laser-scribed graphene lines with subdiffraction widths and spacings. An outstanding gravimetric capacitance of 308 F/g, which is substantially higher than those of reported graphene-based supercapacitors, has been delivered. The results offer a broadly accessible strategy for the fabrication of high-performance graphene-based devices including high-capacity energy storage, high-resolution holograms, high-sensitivity sensors, triboelectric nanogenerators with high power densities, and artificial intelligence devices with high neuron densities.

Inherent Surface Activation of Laser-Scribed Graphene Decorated with Au and Ag Nanoparticles: Simultaneous Electrochemical Behavior toward Uric Acid and Dopamine.

Laser-scribed graphene electrodes (LSGEs) have attracted great attention for the development of electrochemical (bio)sensors due to their excellent electronic properties, large surface area, and high porosity, which enhances the electrons' transfer rate. An increasing active surface area and defect sites are the quickest way to amplify the electrochemical sensing attributes of the electrodes. Here, we have found that the activation procedure coupled to the electrodeposition of metal nanoparticles resulted in a significant amplification of the active area and the analytical performance. This preliminary study is supported by the demonstration of the simultaneous electrochemical sensing of dopamine (DA) and uric acid (UA) by the electrochemically activated LSGEs (LSGE*s). Furthermore, the electrodeposition of two different metal nanoparticles, gold (Au) and silver (Ag), was performed in multiple combinations on working and reference electrodes to investigate the enhancement in the electrochemical response of LSGE*s. Current enhancements of 32, 27, and 35% were observed from LSGE* with WE:Au/RE:LSG/CE:LSGE, WE:Au/RE:Au/CE:LSGE, and WE:Au/RE:Ag/CE:LSGE, compared to the same combinations of LSGEs without any surface activation. A homemade and practical potentiostat, KAUSTat, was used in these electrochemical depositions in this study. Among all of the combinations, the surface area was increased 1.6-, 2.0-, and 1.2-fold for WE:Au/RE:LSG/CE:LSGE, WE:Au/RE:Au/CE:LSGE, and WE:Au/RE:Ag/CE:LSGE prepared from LSGE*s, respectively. To evaluate the analytical performance, DA and UA were detected simultaneously in the presence of ascorbic acid. The LODs of DA and UA are calculated to be ∼0.8 and ∼0.6 μM, respectively. Hence, this study has the potential to open new insights into new surface activation strategies with a combination of one-step nanostructured metal depositions by a custom-made potentiostat. This novel strategy could be an excellent and straightforward method to enhance the electrochemical transducer sensitivity for various electrochemical sensing applications.

A novel electrochemical insulin aptasensor: From glassy carbon electrodes to disposable, single-use laser-scribed graphene electrodes

Insulin, a peptide hormone secreted by pancreatic β cells, affects the development of diabetes and associated complications. Herein, we propose an electrochemical aptasensor for sensitive and selective detection of insulin using laser-scribed graphene electrodes (LSGEs). Before using disposable LSGEs, the development and proof-of-concept sensing experiments were firstly carried out on research-grade glassy carbon electrode (GCE). The aptasensor is based on using Exonuclease I (Exo I) that catalyses the hydrolysis of single-stranded aptamers attached to the electrode surface; however, the hydrolysis does not occur if the insulin is bound to the aptamer. Therefore, the unbound aptamers are cleaved by Exo I while insulin-bound aptamers remain on the electrode surface. In the next step, the gold nanoparticle - aptamer (AuNPs-Apt) probes are introduced to the electrode surface to form a ‘sandwich’ structure with the insulin on the surface-attached aptamer. The redox probe, methylene blue (MB), intercalates into the aptamers' guanine bases and the sandwich structure of AuNPs-Apt/insulin/surface-bound aptamer amplifies electrochemical signal from MBs. The signal can be well-correlated to the concentrations of insulin. A limit of detection of 22.7 fM was found for the LSGE-based sensors and 9.8 fM for GCE-based sensors used for comparison and initial sensor development. The results demonstrate successful fabrication of the single-use and sensitive LSGEs-based sensors for insulin detection.

Paper-based optimized chemical fuel cell with laser-scribed graphene electrodes for energy harvesting

Paper-based optimized chemical fuel cell with laser-scribed graphene electrodes for energy harvesting

Laser-Scribed Graphene (LSG) Fabrication Method for Microwave Circuit Applications

In this letter, a laser-scribed graphene (LSG) fabrication method is used to create graphene to be used in a microwave application, for example, a voltage-tunable microstrip attenuator. Graphene used in microwave circuits, such as tunable attenuators, usually focuses on using exfoliated graphene, deposited graphene nanoplatelets, or microwave irradiation. It will be demonstrated that the fabrication of LSG from graphene oxide on standard double-sided FR-4 copper-clad substrate can be used as a voltage-controlled resistor that results in a tunable microstrip attenuator across the microwave frequencies from 50 MHz to 5.5 GHz.