The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Vladimir V. Tsukruk - One of the best experts on this subject based on the ideXlab platform.
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seriography guided reduction of graphene oxide Biopapers for wearable sensory electronics
Advanced Functional Materials, 2017Co-Authors: Vladimir V. TsukrukAbstract:Novel nacre-mimic bio-nanocomposites, such as graphene-based laminates, are pushing the boundaries of strength and toughness as flexible engineering materials. Translating these material advances to functional flexible electronics requires methods for generating print-scalable microcircuits (conductive elements surrounded by dielectric) into these strong, tough, lightweight bio-nanocomposites. Here, a new paradigm for printing flexible electronics by employing facile, eco-friendly seriography to confine the reduction of graphene oxide Biopapers reinforced by silk interlayers is presented. Well-defined, micropatterned regions on the biopaper are chemically reduced, generating a 106 increase in conductivity (up to 104 S m−1). Flexible, robust graphene-silk circuits are showcased in diverse applications such as resistive moisture sensors and capacitive proximity sensors. Unlike conductive (i.e., graphene- or Ag nanoparticle-loaded) inks printed onto substrates, seriography-guided reduction does not create mechanically weak interfaces between dissimilar materials and does not require the judicious formation of ink. The unimpaired functionality of printed-in graphene-silk microcircuits after thousands of punitive folding cycles and chemical attack by harsh solvents is demonstrated. This novel approach provides a low-cost, portable solution for printing micrometer-scale conductive features uniformly across large areas (>hundreds of cm2) in layered composites for applications including wearable health monitors, electronic skin, rollable antennas, and conformable displays.
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Seriography‐Guided Reduction of Graphene Oxide Biopapers for Wearable Sensory Electronics
Advanced Functional Materials, 2017Co-Authors: Ruilong Ma, Vladimir V. TsukrukAbstract:Novel nacre-mimic bio-nanocomposites, such as graphene-based laminates, are pushing the boundaries of strength and toughness as flexible engineering materials. Translating these material advances to functional flexible electronics requires methods for generating print-scalable microcircuits (conductive elements surrounded by dielectric) into these strong, tough, lightweight bio-nanocomposites. Here, a new paradigm for printing flexible electronics by employing facile, eco-friendly seriography to confine the reduction of graphene oxide Biopapers reinforced by silk interlayers is presented. Well-defined, micropatterned regions on the biopaper are chemically reduced, generating a 106 increase in conductivity (up to 104 S m−1). Flexible, robust graphene-silk circuits are showcased in diverse applications such as resistive moisture sensors and capacitive proximity sensors. Unlike conductive (i.e., graphene- or Ag nanoparticle-loaded) inks printed onto substrates, seriography-guided reduction does not create mechanically weak interfaces between dissimilar materials and does not require the judicious formation of ink. The unimpaired functionality of printed-in graphene-silk microcircuits after thousands of punitive folding cycles and chemical attack by harsh solvents is demonstrated. This novel approach provides a low-cost, portable solution for printing micrometer-scale conductive features uniformly across large areas (>hundreds of cm2) in layered composites for applications including wearable health monitors, electronic skin, rollable antennas, and conformable displays.
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Seriography-Guided Reduction of Graphene Oxide Biopapers for Wearable Sensory Electronics
Advanced Functional Materials, 2017Co-Authors: Ruilong Ma, Vladimir V. TsukrukAbstract:© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Novel nacre-mimic bio-nanocomposites, such as graphene-based laminates, are pushing the boundaries of strength and toughness as flexible engineering materials. Translating these material advances to functional flexible electronics requires methods for generating print-scalable microcircuits (conductive elements surrounded by dielectric) into these strong, tough, lightweight bio-nanocomposites. Here, a new paradigm for printing flexible electronics by employing facile, eco-friendly seriography to confine the reduction of graphene oxide Biopapers reinforced by silk interlayers is presented. Well-defined, micropatterned regions on the biopaper are chemically reduced, generating a 106 increase in conductivity (up to 104 S m-1). Flexible, robust graphene-silk circuits are showcased in diverse applications such as resistive moisture sensors and capacitive proximity sensors. Unlike conductive (i.e., graphene- or Ag nanoparticle-loaded) inks printed onto substrates, seriography-guided reduction does not create mechanically weak interfaces between dissimilar materials and does not require the judicious formation of ink. The unimpaired functionality of printed-in graphene-silk microcircuits after thousands of punitive folding cycles and chemical attack by harsh solvents is demonstrated. This novel approach provides a low-cost, portable solution for printing micrometer-scale conductive features uniformly across large areas (>hundreds of cm2) in layered composites for applications including wearable health monitors, electronic skin, rollable antennas, and conformable displays.
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Self-Powered Electronic Skin with Biotactile Selectivity
Advanced Materials, 2016Co-Authors: Kesong Hu, Ruilong Ma, Rui Xiong, Shuaidi Zhang, Zhong Lin Wang, Vladimir V. TsukrukAbstract:Power-generating flexible thin films for facile detection of biotactile events are fabricated from patterned metal-graphene oxide biopaper. These tactile materials are mechanically robust with a consistent output of 1 V and high response rate of 20 Hz. It is demonstrated that the simple quadruple electronic skin sensitively and selectively recognizes nine spatial biotactile positions and can readily be expanded.
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Written-in conductive patterns on robust graphene oxide biopaper by electrochemical microstamping.
Angewandte Chemie, 2013Co-Authors: Kesong Hu, Lorenzo S. Tolentino, Dhaval D. Kulkarni, Chunhong Ye, Satish Kumar, Vladimir V. TsukrukAbstract:madeby vacuum-assisted assembly have been introduced asprospective superior carbon-only replacements of inorganic-based nanocomposites with excellent mechanical properties,their further progress as protective coatings, electronicsubstrates, electromagnetic shielding, and electromechanicalelements is limited by several issues related to their integra-tion in practical device environment.
Russell K. Pirlo - One of the best experts on this subject based on the ideXlab platform.
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Gene Expression Changes in Long-Term in Vitro Human Blood-Brain Barrier Models and Their Dependence on a Transwell Scaffold Materia
Journal of Healthcare Engineering, 2017Co-Authors: Joel D. Gaston, Lauren L. Bischel, Lisa A. Fitzgerald, Bradley R. Ringeisen, Kathleen D. Cusick, Russell K. PirloAbstract:Disruption of the blood-brain barrier (BBB) is the hallmark of many neurovascular disorders, making it a critically important focus for therapeutic options. However, testing the effects of either drugs or pathological agents is difficult due to the potentially damaging consequences of altering the normal brain microenvironment. Recently, in vitro coculture tissue models have been developed as an alternative to animal testing. Despite low cost, these platforms use synthetic scaffolds which prevent normal barrier architecture, cellular crosstalk, and tissue remodeling. We created a biodegradable electrospun gelatin mat “biopaper” (BP) as a scaffold material for an endothelial/astrocyte coculture model allowing cell-cell contact and crosstalk. To compare the BP and traditional models, we investigated the expression of 27 genes involved in BBB permeability, cellular function, and endothelial junctions at different time points. Gene expression levels demonstrated higher expression of transcripts involved in endothelial junction formation, including TJP2 and CDH5, in the BP model. The traditional model had higher expression of genes associated with extracellular matrix-associated proteins, including SPARC and COL4A1. Overall, the results demonstrate that the BP coculture model is more representative of a healthy BBB state, though both models have advantages that may be useful in disease modeling.
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electrospun gelatin Biopapers as substrate for in vitro bilayer models of blood brain barrier tissue
Journal of Biomedical Materials Research Part A, 2016Co-Authors: Lauren L. Bischel, Bradley R. Ringeisen, Peter K Wu, Peter N Coneski, Jeffrey G Lundin, Carl B Giller, James H Wynne, Russell K. PirloAbstract:: Gaining a greater understanding of the blood-brain barrier (BBB) is critical for improvement in drug delivery, understanding pathologies that compromise the BBB, and developing therapies to protect the BBB. In vitro human tissue models are valuable tools for studying these issues. The standard in vitro BBB models use commercially available cell culture inserts to generate bilayer co-cultures of astrocytes and endothelial cells (EC). Electrospinning can be used to produce customized cell culture substrates with optimized material composition and mechanical properties with advantages over off-the-shelf materials. Electrospun gelatin is an ideal cell culture substrate because it is a natural polymer that can aid cell attachment and be modified and degraded by cells. Here, we have developed a method to produce cell culture inserts with electrospun gelatin "biopaper" membranes. The electrospun fiber diameter and cross-linking method were optimized for the growth of primary human endothelial cell and primary human astrocyte bilayer co-cultures to model human BBB tissue. BBB co-cultures on biopaper were characterized via cell morphology, trans-endothelial electrical resistance (TEER), and permeability to FITC-labeled dextran and compared to BBB co-cultures on standard cell culture inserts. Over longer culture periods (up to 21 days), cultures on the optimized electrospun gelatin Biopapers were found to have improved TEER, decreased permeability, and permitted a smaller separation between co-cultured cells when compared to standard PET inserts.
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plga hydrogel Biopapers as a stackable substrate for printing huvec networks via biolp
Biotechnology and Bioengineering, 2012Co-Authors: Russell K. Pirlo, Peter K Wu, Bradley R. RingeisenAbstract:: Two major challenges in tissue engineering are mimicking the native cell-cell arrangements of tissues and maintaining viability of three-dimension (3D) tissues thicker than 300 µm. Cell printing and prevascularization of engineered tissues are promising approaches to meet these challenges. However, the printing technologies used in biofabrication must balance the competing parameters of resolution, speed, and volume, which limit the resolution of thicker 3D structures. We suggest that high-resolution conformal printing techniques can be used to print 2D patterns of vascular cells onto biopaper substrates which can then be stacked to form a thicker tissue construct. Towards this end we created 1 cm × 1 cm × 300 µm Biopapers to be used as the transferable, stackable substrate for cell printing. 3.6% w/v poly-lactide-co-glycolide was dissolved in chloroform and poured into molds filled with NaCl crystals. The salt was removed with DI water and the scaffolds were dried and loaded with a Collagen Type I or Matrigel. SEM of the Biopapers showed extensive porosity and gel loading throughout. Biological laser printing (BioLP) was used to deposit human umbilical vein endothelial cells (HUVEC) in a simple intersecting pattern to the surface of the Biopapers. The cells differentiated and stretched to form networks preserving the printed pattern. In a separate experiment to demonstrate "stackability," individual Biopapers were randomly seeded with HUVECs and cultured for 1 day. The mechanically stable and viable Biopapers were then stacked and cultured for 4 days. Three-dimensional confocal microscopy showed cell infiltration and survival in the compound multilayer constructs. These results demonstrate the feasibility of stackable "Biopapers" as a scaffold to build 3D vascularized tissues with a 2D cell-printing technique.
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PLGA/hydrogel Biopapers as a stackable substrate for printing HUVEC networks via BioLP™
Biotechnology and Bioengineering, 2011Co-Authors: Russell K. Pirlo, Peter K Wu, Bradley R. RingeisenAbstract:Two major challenges in tissue engineering are mimicking the native cell-cell arrangements of tissues and maintaining viability of three-dimension (3D) tissues thicker than 300 µm. Cell printing and prevascularization of engineered tissues are promising approaches to meet these challenges. However, the printing technologies used in biofabrication must balance the competing parameters of resolution, speed, and volume, which limit the resolution of thicker 3D structures. We suggest that high-resolution conformal printing techniques can be used to print 2D patterns of vascular cells onto biopaper substrates which can then be stacked to form a thicker tissue construct. Towards this end we created 1 cm × 1 cm × 300 µm Biopapers to be used as the transferable, stackable substrate for cell printing. 3.6% w/v poly-lactide-co-glycolide was dissolved in chloroform and poured into molds filled with NaCl crystals. The salt was removed with DI water and the scaffolds were dried and loaded with a Collagen Type I or Matrigel. SEM of the Biopapers showed extensive porosity and gel loading throughout. Biological laser printing (BioLP) was used to deposit human umbilical vein endothelial cells (HUVEC) in a simple intersecting pattern to the surface of the Biopapers. The cells differentiated and stretched to form networks preserving the printed pattern. In a separate experiment to demonstrate "stackability," individual Biopapers were randomly seeded with HUVECs and cultured for 1 day. The mechanically stable and viable Biopapers were then stacked and cultured for 4 days. Three-dimensional confocal microscopy showed cell infiltration and survival in the compound multilayer constructs. These results demonstrate the feasibility of stackable "Biopapers" as a scaffold to build 3D vascularized tissues with a 2D cell-printing technique.
Bradley R. Ringeisen - One of the best experts on this subject based on the ideXlab platform.
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Gene Expression Changes in Long-Term in Vitro Human Blood-Brain Barrier Models and Their Dependence on a Transwell Scaffold Materia
Journal of Healthcare Engineering, 2017Co-Authors: Joel D. Gaston, Lauren L. Bischel, Lisa A. Fitzgerald, Bradley R. Ringeisen, Kathleen D. Cusick, Russell K. PirloAbstract:Disruption of the blood-brain barrier (BBB) is the hallmark of many neurovascular disorders, making it a critically important focus for therapeutic options. However, testing the effects of either drugs or pathological agents is difficult due to the potentially damaging consequences of altering the normal brain microenvironment. Recently, in vitro coculture tissue models have been developed as an alternative to animal testing. Despite low cost, these platforms use synthetic scaffolds which prevent normal barrier architecture, cellular crosstalk, and tissue remodeling. We created a biodegradable electrospun gelatin mat “biopaper” (BP) as a scaffold material for an endothelial/astrocyte coculture model allowing cell-cell contact and crosstalk. To compare the BP and traditional models, we investigated the expression of 27 genes involved in BBB permeability, cellular function, and endothelial junctions at different time points. Gene expression levels demonstrated higher expression of transcripts involved in endothelial junction formation, including TJP2 and CDH5, in the BP model. The traditional model had higher expression of genes associated with extracellular matrix-associated proteins, including SPARC and COL4A1. Overall, the results demonstrate that the BP coculture model is more representative of a healthy BBB state, though both models have advantages that may be useful in disease modeling.
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electrospun gelatin Biopapers as substrate for in vitro bilayer models of blood brain barrier tissue
Journal of Biomedical Materials Research Part A, 2016Co-Authors: Lauren L. Bischel, Bradley R. Ringeisen, Peter K Wu, Peter N Coneski, Jeffrey G Lundin, Carl B Giller, James H Wynne, Russell K. PirloAbstract:: Gaining a greater understanding of the blood-brain barrier (BBB) is critical for improvement in drug delivery, understanding pathologies that compromise the BBB, and developing therapies to protect the BBB. In vitro human tissue models are valuable tools for studying these issues. The standard in vitro BBB models use commercially available cell culture inserts to generate bilayer co-cultures of astrocytes and endothelial cells (EC). Electrospinning can be used to produce customized cell culture substrates with optimized material composition and mechanical properties with advantages over off-the-shelf materials. Electrospun gelatin is an ideal cell culture substrate because it is a natural polymer that can aid cell attachment and be modified and degraded by cells. Here, we have developed a method to produce cell culture inserts with electrospun gelatin "biopaper" membranes. The electrospun fiber diameter and cross-linking method were optimized for the growth of primary human endothelial cell and primary human astrocyte bilayer co-cultures to model human BBB tissue. BBB co-cultures on biopaper were characterized via cell morphology, trans-endothelial electrical resistance (TEER), and permeability to FITC-labeled dextran and compared to BBB co-cultures on standard cell culture inserts. Over longer culture periods (up to 21 days), cultures on the optimized electrospun gelatin Biopapers were found to have improved TEER, decreased permeability, and permitted a smaller separation between co-cultured cells when compared to standard PET inserts.
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plga hydrogel Biopapers as a stackable substrate for printing huvec networks via biolp
Biotechnology and Bioengineering, 2012Co-Authors: Russell K. Pirlo, Peter K Wu, Bradley R. RingeisenAbstract:: Two major challenges in tissue engineering are mimicking the native cell-cell arrangements of tissues and maintaining viability of three-dimension (3D) tissues thicker than 300 µm. Cell printing and prevascularization of engineered tissues are promising approaches to meet these challenges. However, the printing technologies used in biofabrication must balance the competing parameters of resolution, speed, and volume, which limit the resolution of thicker 3D structures. We suggest that high-resolution conformal printing techniques can be used to print 2D patterns of vascular cells onto biopaper substrates which can then be stacked to form a thicker tissue construct. Towards this end we created 1 cm × 1 cm × 300 µm Biopapers to be used as the transferable, stackable substrate for cell printing. 3.6% w/v poly-lactide-co-glycolide was dissolved in chloroform and poured into molds filled with NaCl crystals. The salt was removed with DI water and the scaffolds were dried and loaded with a Collagen Type I or Matrigel. SEM of the Biopapers showed extensive porosity and gel loading throughout. Biological laser printing (BioLP) was used to deposit human umbilical vein endothelial cells (HUVEC) in a simple intersecting pattern to the surface of the Biopapers. The cells differentiated and stretched to form networks preserving the printed pattern. In a separate experiment to demonstrate "stackability," individual Biopapers were randomly seeded with HUVECs and cultured for 1 day. The mechanically stable and viable Biopapers were then stacked and cultured for 4 days. Three-dimensional confocal microscopy showed cell infiltration and survival in the compound multilayer constructs. These results demonstrate the feasibility of stackable "Biopapers" as a scaffold to build 3D vascularized tissues with a 2D cell-printing technique.
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PLGA/hydrogel Biopapers as a stackable substrate for printing HUVEC networks via BioLP™
Biotechnology and Bioengineering, 2011Co-Authors: Russell K. Pirlo, Peter K Wu, Bradley R. RingeisenAbstract:Two major challenges in tissue engineering are mimicking the native cell-cell arrangements of tissues and maintaining viability of three-dimension (3D) tissues thicker than 300 µm. Cell printing and prevascularization of engineered tissues are promising approaches to meet these challenges. However, the printing technologies used in biofabrication must balance the competing parameters of resolution, speed, and volume, which limit the resolution of thicker 3D structures. We suggest that high-resolution conformal printing techniques can be used to print 2D patterns of vascular cells onto biopaper substrates which can then be stacked to form a thicker tissue construct. Towards this end we created 1 cm × 1 cm × 300 µm Biopapers to be used as the transferable, stackable substrate for cell printing. 3.6% w/v poly-lactide-co-glycolide was dissolved in chloroform and poured into molds filled with NaCl crystals. The salt was removed with DI water and the scaffolds were dried and loaded with a Collagen Type I or Matrigel. SEM of the Biopapers showed extensive porosity and gel loading throughout. Biological laser printing (BioLP) was used to deposit human umbilical vein endothelial cells (HUVEC) in a simple intersecting pattern to the surface of the Biopapers. The cells differentiated and stretched to form networks preserving the printed pattern. In a separate experiment to demonstrate "stackability," individual Biopapers were randomly seeded with HUVECs and cultured for 1 day. The mechanically stable and viable Biopapers were then stacked and cultured for 4 days. Three-dimensional confocal microscopy showed cell infiltration and survival in the compound multilayer constructs. These results demonstrate the feasibility of stackable "Biopapers" as a scaffold to build 3D vascularized tissues with a 2D cell-printing technique.
D. Lima - One of the best experts on this subject based on the ideXlab platform.
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Direct Human Cartilage Repair Using Three-Dimensional Bioprinting Technology
Tissue engineering: Part A, 2012Co-Authors: Xiao Feng Cui, Darryl D D Lima, Kurt Breitenkamp, X. Cui, Martin Lotz, M. G. Finn, D. LimaAbstract:Current cartilage tissue engineering strategies cannot as yet fabricate new tissue that is indistinguishable from native cartilage with respect to zonal organization, extracellular matrix composition, and mechanical properties. Integra-tion of implants with surrounding native tissues is crucial for long-term stability and enhanced functionality. In this study, we developed a bioprinting system with simultaneous photopolymerization capable for three-dimensional (3D) cartilage tissue engineering. Poly(ethylene glycol) dimethacrylate (PEGDMA) with human chondrocytes were printed to repair defects in osteochondral plugs (3D biopaper) in layer-by-layer assembly. Compressive modulus of printed PEGDMA was 395.73 – 80.40 kPa, which was close to the range of the properties of native human articular cartilage. Printed human chondrocytes maintained the initially deposited positions due to simultaneous photo-polymerization of surrounded biomaterial scaffold, which is ideal in precise cell distribution for anatomic cartilage engineering. Viability of printed human chondrocytes increased 26% in simultaneous polymerization than poly-merized after printing. Printed cartilage implant attached firmly with surrounding tissue and greater proteoglycan deposition was observed at the interface of implant and native cartilage in Safranin-O staining. This is consistent with the enhanced interface failure strength during the culture assessed by push-out testing. Printed cartilage in 3D biopaper had elevated glycosaminoglycan (GAG) content comparing to that without biopaper when normalized to DNA. These observations were consistent with gene expression results. This study indicates the importance of direct cartilage repair and promising anatomic cartilage engineering using 3D bioprinting technology.
Ruilong Ma - One of the best experts on this subject based on the ideXlab platform.
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Seriography‐Guided Reduction of Graphene Oxide Biopapers for Wearable Sensory Electronics
Advanced Functional Materials, 2017Co-Authors: Ruilong Ma, Vladimir V. TsukrukAbstract:Novel nacre-mimic bio-nanocomposites, such as graphene-based laminates, are pushing the boundaries of strength and toughness as flexible engineering materials. Translating these material advances to functional flexible electronics requires methods for generating print-scalable microcircuits (conductive elements surrounded by dielectric) into these strong, tough, lightweight bio-nanocomposites. Here, a new paradigm for printing flexible electronics by employing facile, eco-friendly seriography to confine the reduction of graphene oxide Biopapers reinforced by silk interlayers is presented. Well-defined, micropatterned regions on the biopaper are chemically reduced, generating a 106 increase in conductivity (up to 104 S m−1). Flexible, robust graphene-silk circuits are showcased in diverse applications such as resistive moisture sensors and capacitive proximity sensors. Unlike conductive (i.e., graphene- or Ag nanoparticle-loaded) inks printed onto substrates, seriography-guided reduction does not create mechanically weak interfaces between dissimilar materials and does not require the judicious formation of ink. The unimpaired functionality of printed-in graphene-silk microcircuits after thousands of punitive folding cycles and chemical attack by harsh solvents is demonstrated. This novel approach provides a low-cost, portable solution for printing micrometer-scale conductive features uniformly across large areas (>hundreds of cm2) in layered composites for applications including wearable health monitors, electronic skin, rollable antennas, and conformable displays.
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Seriography-Guided Reduction of Graphene Oxide Biopapers for Wearable Sensory Electronics
Advanced Functional Materials, 2017Co-Authors: Ruilong Ma, Vladimir V. TsukrukAbstract:© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Novel nacre-mimic bio-nanocomposites, such as graphene-based laminates, are pushing the boundaries of strength and toughness as flexible engineering materials. Translating these material advances to functional flexible electronics requires methods for generating print-scalable microcircuits (conductive elements surrounded by dielectric) into these strong, tough, lightweight bio-nanocomposites. Here, a new paradigm for printing flexible electronics by employing facile, eco-friendly seriography to confine the reduction of graphene oxide Biopapers reinforced by silk interlayers is presented. Well-defined, micropatterned regions on the biopaper are chemically reduced, generating a 106 increase in conductivity (up to 104 S m-1). Flexible, robust graphene-silk circuits are showcased in diverse applications such as resistive moisture sensors and capacitive proximity sensors. Unlike conductive (i.e., graphene- or Ag nanoparticle-loaded) inks printed onto substrates, seriography-guided reduction does not create mechanically weak interfaces between dissimilar materials and does not require the judicious formation of ink. The unimpaired functionality of printed-in graphene-silk microcircuits after thousands of punitive folding cycles and chemical attack by harsh solvents is demonstrated. This novel approach provides a low-cost, portable solution for printing micrometer-scale conductive features uniformly across large areas (>hundreds of cm2) in layered composites for applications including wearable health monitors, electronic skin, rollable antennas, and conformable displays.
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Self-Powered Electronic Skin with Biotactile Selectivity
Advanced Materials, 2016Co-Authors: Kesong Hu, Ruilong Ma, Rui Xiong, Shuaidi Zhang, Zhong Lin Wang, Vladimir V. TsukrukAbstract:Power-generating flexible thin films for facile detection of biotactile events are fabricated from patterned metal-graphene oxide biopaper. These tactile materials are mechanically robust with a consistent output of 1 V and high response rate of 20 Hz. It is demonstrated that the simple quadruple electronic skin sensitively and selectively recognizes nine spatial biotactile positions and can readily be expanded.
