| 1. |
- Tehrani, Payman, 1977-, et al.
(författare)
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Evaluation of active materials designed for use in printable electrochromic polymer displays
- 2006
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:4, s. 2485-2492
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Tidskriftsartikel (refereegranskat)abstract
- In a step towards roll-to-roll production of polymer-based electrochromic displays on flexible substrates, nine thiophene-based polymers and copolymers designed to increase the contrast of displays based on poly(3,4-ethylenedioxythiophene)/poly(styrene-sulfonic acid) have been synthesized and evaluated with respect to their absorbance (contrast), switch speed, and ability to switch reversibly in a water-based electrolyte. The results of the evaluation, including cyclic voltammetry and optically visible absorption, provide a basis for understanding what an aqueous electrolyte electrochromic display requires in terms of oxidation potential and material stability, and the effect of chemical structure on the reversibility and speed of switching. © 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Hansson, Kenny, 1972-, et al.
(författare)
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Whole blood coagulation on protein adsorption-resistant PEG and peptide functionalised PEG-coated titanium surfaces.
- 2005
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 26:8, s. 861-72
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate whole blood coagulation on low blood plasma protein adsorbing surfaces. For this purpose, the polycationic graft copolymer poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG), PLL-g-PEG grafted with a cell adhesive peptide containing the amino acid sequence -Arg-Gly-Asp- (RGD), and PLL-g-PEG with a control peptide -Arg-Asp-Gly- (RDG) were adsorbed onto titanium (oxide), forming stable monomolecular adlayers through electrostatic attraction. Free oscillation rheometry and complementary techniques were used to measure the coagulation time (CT) and other interactions of the surfaces with native whole blood, recalcified platelet-rich plasma (PRP), and recalcified citrated platelet-free plasma (PFP). The results show that the uncoated titanium surfaces (reference) activated platelets and quickly triggered the coagulation cascade via the intrinsic pathway, whereas the PLL-g-PEG surfaces displayed a prolonged CT, approximately 2-3 times longer compared to uncoated titanium. We hypothesise that blood coagulates outside the vascular system independent of low protein adsorption to or activation by surfaces, due to the absence of an active down-regulation of procoagulative processes by the vascular endothelium.
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| 3. |
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| 5. |
- Isaksson, Joakim, 1977-
(författare)
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On the Surface of Conducting Polymers : Electrochemical Switching of Color and Wettability in Conjugated Polymer Devices
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the discovery in 1977 that conjugated polymers can be doped to achieve almost metallic electronic conduction, the research field of conducting polymers has escalated, with applications such as light emitting diodes, solar cells, thin film transistors, electrochemical transistors, logic circuits and sensors. The materials can be chemically modified during their synthesis in order to tailor the desired mechanical, electronic and optical properties of the final product. Polymers are also generally possible to process from solution, and regular roll-to-roll printing techniques can therefore be used for manufacturing of electronic components on flexible substrates like plastic or paper. On top of that, the nature of conjugated polymers enables the creation of devices with novel properties, which are not possible to achieve by using inorganic materials such as silicon.The work presented in this thesis mainly focuses on devices that utilize two rather unique properties of conducting polymers. Conducting polymers are generally electrochromic, i.e. they change color upon electrochemical oxidation or reduction, and can therefore be used as both conductor and pixel element in simple organic displays. As a result of the electrochemical reaction, some polymers also alter their surface properties and have proven to be suitable materials for organic electronic wettability switches. Control of surface wettability has applications in such diverse areas as printing techniques, micro-fluidics and biomaterials.The aim of the thesis is to briefly describe the physical and chemical background of the materials used in organic electronic devices. Topics include molecular properties and doping of conjugated polymers, electrochromism, surface tension etc. This slightly theoretical part is followed by a more detailed explanation of device design, functionality and characterization. Finally, a glance into future projects will also be presented.
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| 6. |
- Isaksson, Joakim, 1977-
(författare)
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Organic Bioelectronics : Electrochemical Devices using Conjugated Polymers
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the Nobel Prize awarded discovery that some polymers or “plastics” can be made electronically conducting, the scientific field of organic electronics has arisen. The use of conducting polymers in electronic devices is appealing, because the materials can be processed from a liquid phase, much like ordinary non-conducting plastics. This gives the opportunity to utilize printing technologies and manufacture electronics roll-to-roll on flexible substrates, ultimately at very low costs. Even more intriguing are the possibilities to achieve completely novel functionalities in combination with the inherent compatibility of these materials with biological species. Therefore, organic electronics can be merged with biology and medicine to create organic bioelectronics, i.e. organic electronic devices that interact with biological samples directly or are used for biological applications.This thesis aims at giving a background to the field of organic bioelectronics and focuses on how electrochemical devices may be utilized. An organic electronic wettability switch that can be used for lab-on-a-chip applications and control of cell growth as well as an electrochemical ion pump for cell communication and drug delivery are introduced. Furthermore, the underlying electrochemical structures that are the basis for the above mentioned devices, electrochemical display pixels etc. are discussed in detail. In summary, the work contributes to the understanding of electrochemical polymer electronics and, by presenting new bioelectronic inventions, builds a foundation for future projects and discoveries.
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| 7. |
- Robinson, Linda, 1975-, et al.
(författare)
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Electrochemical wettability switches gate aqueous liquids in microfluidic systems
- 2006
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 6, s. 1277-1278
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a simple low-voltage technique for gating the flow of aqueous liquids in microfluidic systems employing the electrochemically-controlled surface energy of the conjugated polymer poly(3-hexylthiophene).
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