| 1. |
- Backe, Carin, et al.
(författare)
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Serially connected EAP based tape yarns for in-air actuation using textile structures
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Smart textiles that have the capability for actuation are of great interest for creating wearables and haptic devices. Through the use of textile fabric production processes electroactive polymeric materials in the form of film-based yarns can be integrated and combined with passive yarns to create soft, actuating fabrics. This way single EAP materials can be transformed into segments consisting of multiple EAP yarns working together. Furthermore, these segments can be positioned within a fabric to work individually or simultaneously in different patterns by use of incorporated conductive yarn paths. While the chase for additivity in force is a long-standing part of developing new actuator structures, so is the need for additivity in displacement motion. Here we construct an actuating textile fabric through the process of weaving that is able to operate in-air using polypyrrole-based tape yarns with choline acetate ionic liquid. Finding the balance between the weaving parameters turned out to be key. We found that in a vertically suspended arrangement, a three-segment serially connected fabric assembly demonstrated an accumulative effect in displacement and a joint-like motion behaviour. This opens up for more complicated motion patterns to be created through textile processing of EAP materials.
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| 2. |
- Baumgartner, Johanna, et al.
(författare)
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Switchable presentation of cytokines on electroactive polypyrrole surfaces for hematopoietic stem and progenitor cells
- 2018
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Ingår i: Journal of Materials Chemistry B. - Cambridge : Royal Society of Chemistry. - 2050-750X .- 2050-7518. ; 6:28, s. 4665-4675
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoietic stem cells are used in transplantations for patients with hematologic malignancies. Scarce sources require efficient strategies of expansion, including polymeric biomaterials mimicking architectures of bone marrow tissue. Tissue microenvironment and mode of cytokine presentation strongly influence cell fate. Although several cytokines with different functions as soluble or membrane-bound mediators have already been identified, their precise roles have not yet been clarified. A need exists for in vitro systems that mimic the in vivo situation to enable such studies. One way is to establish surfaces mimicking physiological presentation using protein-immobilization onto polymer films. However these films merely provide a static presentation of the immobilized proteins. It would be advantageous to also dynamically change protein presentation and functionality to better reflect the in vivo conditions. The electroactive polymer polypyrrole shows excellent biocompatibility and electrochemically alters its surface properties, becoming an interesting choice for such setups. Here, we present an in vitro system for switchable presentation of membrane-bound cytokines. We use interleukin IL-3, known to affect hematopoiesis, and show that when immobilized on polypyrrole films, IL-3 is bioavailable for the bone marrow-derived FDC-P1 progenitor cell line. Moreover, IL-3 presentation can be successfully altered by changing the redox state of the film, in turn influencing FDC-P1 cell viability. This novel in vitro system provides a valuable tool for stimuli-responsive switchable protein presentation allowing the dissection of relevant mediators in stem and progenitor cell behavior.
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| 3. |
- Bruns, Mathis, et al.
(författare)
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A Straightforward Approach of Wet-Spinning Poly(3,4-ethylenedioxythiophene):Polystyrene Sulfate Fibers for Use in All Conducting Polymer-Based Textile Actuators
- 2024
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Ingår i: ADVANCED INTELLIGENT SYSTEMS. - : WILEY. - 2640-4567.
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Tidskriftsartikel (refereegranskat)abstract
- Poly(3,4-ethylenedioxythiophene) (PEDOT), an inherently electrically conductive or conjugated polymer (CP), exhibits the potential to play a significant role in the development of innovative fiber materials for use in smart textiles, such as wearables. Furthermore, these fibers can function as artificial muscles in the emerging field of interactive fiber rubber composites. This study introduces a straightforward and efficient method for creating PEDOT-based, biomimetic, fiber-shaped, linearly contracting ionic electroactive polymer actuators. To achieve this, a wet-spinning technique is presented, which enables a continuous production of PEDOT:polystyrene sulfate (PSS) fibers at high production rates of 34 m h-1, an additional fiber washing step and a sulfuric acid posttreatment step to increase the fibers conductivity. The fibers provide a high conductivity of 1028 S cm-1, maximum tensile strength reaching 182 MPa, and a maximum elongation of 24%. When utilized as CP actuators in an aqueous sodium dodecylbenzenesulfonate electrolyte medium, the fibers demonstrate a repeatable maximum isometric contractile force of 1.64 mN and repeatable linear contractile strain up to 0.56%. Furthermore, a high level of cyclic long-term actuation stability can be demonstrated. Notably, these contractile strains are, to the best of knowledge, the highest reported values for pristine PEDOT:PSS fibers. This study introduces a wet-spinning method for high-volume production of poly(3,4-ethylenedioxythiophene):polystyrene sulfate-based conducting polymer fibers, spanning tens to hundreds of meters. Evaluating their physical properties, with emphasis on actuation, reveals robust and stable actuation capabilities, promising for integration into intelligent textiles for wearables or soft robotics with sensing or actuating functionalities.image (c) 2024 WILEY-VCH GmbH
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| 4. |
- Cao, Danfeng, 1991-, et al.
(författare)
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Soft actuators that self-create bone for biohybrid (micro)robotics
- 2022
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Ingår i: Proceedings of The 5th International Conference on Manipulation, Automation, And Robotics at Small Scales (MARSS 2022). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665459730 - 9781665459747 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- Here we present a new class of variable stiffness actuators for soft robotics based on biohybrid materials that change their state from soft-to-hard by creating their own bones. The biohybrid variable stiffness soft actuators were fabricated by combining the electromechanically active polymer polypyrrole (PPy) with a soft substrate of polydimethylsiloxane or alginate gel. These actuators were functionalized with cell-derived plasma membrane nanofragments (PMNFs), which promote rapid mineralization within 2 days. These actuators were used in robotic devices, and PMNF mineralization resulted in the robotic devices to achieve a soft to stiff state change and thereby a decreased or stopped actuation. Moreover, perpendicularly and diagonally patterned actuators were prepared. The patterned actuators showed programmed directional actuation motion and could be fixated in this programmed state. Finally, patterned actuators that combined soft and rigid parts in one actuator showed more complex actuation motion. Together, these variable stiffness actuators could expand the range of applications of morphing robotics with more complex structures and functions.
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| 5. |
- Guan, Na N., et al.
(författare)
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The role of ATP signalling in response to mechanical stimulation studied in T24 cells using new microphysiological tools
- 2018
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Ingår i: Journal of Cellular and Molecular Medicine (Print). - : Wiley. - 1582-1838 .- 1582-4934. ; 22:4, s. 2319-2328
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Tidskriftsartikel (refereegranskat)abstract
- The capacity to store urine and initiate voiding is a valued characteristic of the human urinary bladder. To maintain this feature, it is necessary that the bladder can sense when it is full and when it is time to void. The bladder has a specialized epithelium called urothelium that is believed to be important for its sensory function. It has been suggested that autocrine ATP signalling contributes to this sensory function of the urothelium. There is well‐established evidence that ATP is released via vesicular exocytosis as well as by pannexin hemichannels upon mechanical stimulation. However, there are still many details that need elucidation and therefore there is a need for the development of new tools to further explore this fascinating field. In this work, we use new microphysiological systems to study mechanostimulation at a cellular level: a mechanostimulation microchip and a silicone‐based cell stretcher. Using these tools, we show that ATP is released upon cell stretching and that extracellular ATP contributes to a major part of Ca2+ signalling induced by stretching in T24 cells. These results contribute to the increasing body of evidence for ATP signalling as an important component for the sensory function of urothelial cells. This encourages the development of drugs targeting P2 receptors to relieve suffering from overactive bladder disorder and incontinence.
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| 6. |
- Herland, Anna, et al.
(författare)
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Electrochemical Control of Growth Factor Presentation To Steer Neural Stem Cell Differentiation
- 2011
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Ingår i: Angewandte Chemie International Edition. - Weinheim : Wiley-VCH Verlagsgesellschaft. - 1433-7851 .- 1521-3773. ; 50:52, s. 12529-12533
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Tidskriftsartikel (refereegranskat)abstract
- Graphical Abstract Let it grow: The conjugated polymer poly(3,4-ethylenedioxythiophene) (PEDOT) was synthesized with heparin as the counterion to form a cell culture substrate. The surface of PEDOT:heparin in the neutral state associated biologically active growth factors (see picture). Electrochemical in situ oxidation of PEDOT during live cell culture decreased the bioavailability of the growth factor and created an exact onset of neural stem cell differentiation.
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| 7. |
- Huniade, Claude, 1996-, et al.
(författare)
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EMIm-OTf Ionogel Coated Fibres - Characterisation and Development, Aiming at Ionic Smart Textiles
- 2021
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ions are prevalent within bioelectronics, as they are the main charge carriers in living systems. In contrast to electronic systems, ionic ones are closer to what can be found in our body; in muscles, neurons and nerves.Textiles are a much-used biomedical material, both in vivo and in vitro due to its membrane character, highly efficient area, softness, biocompatibility and biodegradability. Modifying the physicochemical properties of the core or the surface of textile has been reported a countless number of times, but still, its use in a bioelectrical context is limited.Fibres are the building blocks of textiles and what make textiles an architected class of material. Then ionically conductive fibres are of great interest.Here, we show the preparation of iono-conductive textile fibres through the (semi-)continuous dip-coating of ionogel on the cellulose-based viscose.Ionogels are composed of salts in liquid state and a 3-dimensional solid network, in our case an ionic liquid (IL), 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate, commonly named EMIm OTf or EMIm Triflate, and a thiol acrylate network, allowing the mobility of the ions within or in/out of the gel. This specific combination is a first effort towards the development of ionic textile fibres and ionic smart textiles, as a variety of ILs with different cations and anions exists, potentially allowing a large number of different combinations.We investigate how the coating of this ionogel affects the mechanical properties as well as the conductivity in AC or DC arrangement and their relation to temperature and humidity. Also, the thermal stability and sensitivity of degradation of the fibre system is studied.Moreover, we introduce different textile structures, and potential applications directed to bioelectronics.
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| 8. |
- Huniade, Claude, 1996-, et al.
(författare)
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Investigating ionic liquid-based click-ionogels by thiol-ene photopolymerisation onto textile yarns/fibres
- 2021
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Electronic textiles’ primordial component are the connections that allow a circuit to be formed. As for today, the catalogue of conductive yarns is expanded to highly conductive metals such as copper, silver and steel, or electroconductive plastics composed of conductive polymers and electroconductive fillers such as metal particles or carbon allotropes.Ionic liquids are also able to carry electrical charges, and their capacity to conduct electricity has yet to be investigated as a yarn component, e.g. an ion conducting coating.Here, we report on attempts to coat ionic liquid-based click-ionogel on fibres, using thiol-ene reactions with the help of a photobase generator.Ionogel precursors, composed of plurithiol precursors, acrylate monomers and a triflate ionic-liquid, are applied on yarn and then cured by UV irradiation, initiating the Michael reaction and creating the thiol-acrylate-triflate network around the yarn.The aim of the present study is to prepare and characterise yarns coated with such ionogels, while developing a continuous yarn coating process.Several different ionogel compositions and different yarn topologies are investigated, comparing their structure, electrical conductivity, mechanical properties, thermal stability, behaviour to chemical reagents, as well as the different surface tensions and interfacial interactions.Textile processability is explored by the manufacture of simple fabrics.An application for those ionic conductive coating is the ion supply for electroactive polymers coated yarns that currently rely on electrolytes. This novel coating will render the light-weight property of textile valuable, and therefore broadening their application as wearables.
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| 9. |
- Immerstrand, Charlotte, 1974-, et al.
(författare)
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Altered impedance during pigment aggregation in Xenopus laevis melanophores
- 2003
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Ingår i: Medical and Biological Engineering and Computing. - 0140-0118 .- 1741-0444. ; 41:3, s. 357-364
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Tidskriftsartikel (refereegranskat)abstract
- Melanophores are dark-brown pigment cells located in the skin of amphibia, fish and many invertebrates. The skin colour of these organisms is regulated by the translocation of pigment organelles, and the pigment distribution can be altered by external stimuli. The ability to change colour in response to stimuli makes these cells of interest for biosensing applications. It was investigated whether pigment aggregation in Xenopus laevis melanophores can be detected by impedance measurements performed in transparent microvials. The results show that cell attachment, cell spreading and pigment aggregation all resulted in impedance changes, seen particularly at the highest frequency tested (10 kHz). The mechanisms behind the impedance changes were investigated by the addition of latrunculin or melatonin, both of which cause pigment aggregation. The latrunculin-induced aggregation was associated with cell area decrease and filamentous actin (F-actin) breakdown, processes that can influence the impedance. Lack of F-actin breakdown and an increase in cell area during melatonin-induced aggregation suggest that some other intracellular process also contributes to the impedance decrease seen for melatonin. It was shown that impedance measurements reflect not only cell attachment and cell spreading, but also intracellular events.
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| 10. |
- Inganäs, Olle, et al.
(författare)
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Electrochemomechanical devices from polymer conductors and semiconductors
- 2001. - 2
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Ingår i: Encyclopedia of materials. - Oxford : Elsevier. - 9780080431529 ; , s. 2531-2535
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Conjugated polymer (CP) actuators are devices where the volume of a CP material is changed during a change of the state of oxidation or reduction of the polymer. The volume change is extracted as a geo-metrical change in uni- or bimorphs, where the active material may be combined with the passive supporting material. In bimorphs, which have an active layer supported on a passive Ælm, bending of the assembly occurs as the dimensional change is driven by electrochemistry.
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