Laser In-Situ synthesis of metallic cobalt decorated porous graphene for flexible In-Plane microsupercapacitors

Direct Laser Processing and Functionalizing PI/PDMS Composites for an On-Demand, Programmable, Recyclable Device Platform

Skin-interfaced high-sensitive biosensing systems to detect electrophysiological and biochemical signals have shown great potential in personal health monitoring and disease management. However, the integration of 3D porous nanostructures for improved sensitivity and various functional composites for signal transduction/processing/transmission often relies on different materials and complex fabrication processes, leading to weak interfaces prone to failure upon fatigue or mechanical deformations. The integrated system also needs additional adhesive to strongly conform to the human skin, which can also cause irritation, alignment issues, and motion artifacts. This work introduces a skin-attachable, reprogrammable, multifunctional, adhesive device patch fabricated by simple and low-cost laser scribing of an adhesive composite with polyimide powders and amine-based ethoxylated polyethylenimine dispersed in the silicone elastomer. The obtained laser-induced graphene in the adhesive composite can be further selectively functionalized with conductive nanomaterials or enzymes for enhanced electrical conductivity or selective sensing of various sweat biomarkers. The possible combination of the sensors for real-time biofluid analysis and electrophysiological signal monitoring with RF energy harvesting and communication promises a standalone stretchable adhesive device platform based on the same material system and fabrication process.

Laser-inducedin situsynthesis of nano-composite Co-Co3O4-rGO on paper: miniaturized biosensor for alkaline phosphatase detection

Recent progress in thein situsynthesise of various nanomaterials has gained tremendous interest and wide applications in various fields. For the first time to the best of our knowledge, this work reports a methodology of ultra-fastin situsynthesis of cobalt-cobalt oxide-reduced graphene oxide (Co-Co₃O₄-rGO (CC-rGO)) composite by laser ablation. The photothermal reduction technique was leveraged to develop the CC-rGO. For this, a low-cost 450 nm blue diode laser was irradiated onto a grade 1 filter paper in the presence of cobalt ions readily patterns the carbon matrix of paper to the composite material. Moreover, the variation of cobalt concentrations from 0.1-0.5 M led to structural and morphological changes. Standard techniques were adopted for thorough characterizations of developed sensor material for conductivity analysis, specific surface area, crystal-structural information, surface morphology, and chemical composition. The observed results were highly promoting towards the electrochemical sensing applications. Further, the developed sensor was found to be highly selective toward detecting a vital bio analyte alkaline phosphatase (ALP). The sensors performance was highly significant in the linear range of 10-800 mU l^-1with a detection limit of 10.13 mU l^-1. The sensors applicability was further validated in actual human serum samples via a recovery-based approach. In the future, the developedin situmaterial methodology can begin a rapid composite material synthesis at a larger scale.

Vanadium Oxide-Doped Laser-Induced Graphene Multi-Parameter Sensor to Decouple Soil Nitrogen Loss and Temperature

Monitoring nitrogen utilization efficiency and soil temperature in agricultural systems for timely intervention is essential for crop health with reduced environmental pollution. Herein, this work presents a high-performance multi-parameter sensor based on vanadium oxide (VOX )-doped laser-induced graphene (LIG) foam to completely decouple nitrogen oxides (NOX ) and temperature. The highly porous 3D VOX -doped LIG foam composite is readily obtained by laser scribing vanadium sulfide (V5 S8 )-doped block copolymer and phenolic resin self-assembled films. The heterojunction formed at the LIG/VOX interface provides the sensor with enhanced response to NOX and an ultralow limit of detection of 3 ppb (theoretical estimate of 451 ppt) at room temperature. The sensor also exhibits a wide detection range, fast response/recovery, good selectivity, and stability over 16 days. Meanwhile, the sensor can accurately detect temperature over a wide linear range of 10-110 °C. The encapsulation of the sensor with a soft membrane further allows for temperature sensing without being affected by NOX . The unencapsulated sensor operated at elevated temperature removes the influences of relative humidity and temperature variations for accurate NOX measurements. The capability to decouple nitrogen loss and soil temperature paves the way for the development of future multimodal decoupled electronics for precision agriculture and health monitoring.

Laser Processing of Flexible In-Plane Micro-supercapacitors: Progresses in Advanced Manufacturing of Nanostructured Electrodes

Flexible in-plane architecture micro-supercapacitors (MSCs) are competitive candidates for on-chip miniature energy storage applications owing to their light weight, small size, high flexibility, as well as the advantages of short charging time, high power density, and long cycle life. However, tedious and time-consuming processes are required for the manufacturing of high-resolution interdigital electrodes using conventional approaches. In contrast, the laser processing technique enables high-efficiency high-precision patterning and advanced manufacturing of nanostructured electrodes. In this review, the recent advances in laser manufacturing and patterning of nanostructured electrodes for applications in flexible in-plane MSCs are comprehensively summarized. Various laser processing techniques for the synthesis, modification, and processing of interdigital electrode materials, including laser pyrolysis, reduction, oxidation, growth, activation, sintering, doping, and ablation, are discussed. In particular, some special features and merits of laser processing techniques are highlighted, including the impacts of laser types and parameters on manufacturing electrodes with desired morphologies/structures and their applications on the formation of high-quality nanoshaped graphene, the selective deposition of nanostructured materials, the controllable nanopore etching and heteroatom doping, and the efficient sintering of nanometal products. Finally, the current challenges and prospects associated with the laser processing of in-plane MSCs are also discussed. This review will provide a useful guidance for the advanced manufacturing of nanostructured electrodes in flexible in-plane energy storage devices and beyond.