| 1. |
- Jager, Edwin, 1973-, et al.
(författare)
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Perpendicular Actuation with Individually Controlled Polymer Microactuators
- 2001
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Ingår i: Advanced Materials. - 0935-9648 .- 1521-4095. ; 13:1, s. 76-79
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Tidskriftsartikel (refereegranskat)abstract
- Actuator systems based on conducting polymers, such as polypyrole, with which three-dimensional movement can be controlled, are described. The Figure shows a combination of two such microactuators which are used to “kick” a glass bead across the surface of a silicon wafer. The microfabrication methods used to produce the systems are described and the potential uses, for example microrobotic arms, discussed.
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| 2. |
- Aziz, Shazed, et al.
(författare)
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Plant-Like Tropisms in Artificial Muscles
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- Helical plants have the ability of tropisms to respond to natural stimuli, and biomimicry of such helical shapes into artificial muscles has been vastly popular. However, the shape-mimicked actuators only respond to artificially provided stimulus, they are not adaptive to variable natural conditions, thus being unsuitable for real-life applications where on-demand, autonomous operations are required. Novel artificial muscles made of hierarchically patterned helically wound yarns that are self-adaptive to environmental humidity and temperature changes are demonstrated here. Unlike shape-mimicked artificial muscles, a unique microstructural biomimicking approach is adopted, where the muscle yarns can effectively replicate the hydrotropism and thermotropism of helical plants to their microfibril level using plant-like microstructural memories. Large strokes, with rapid movement, are obtained when the individual microfilament of yarn is inlaid with hydrogel and further twisted into a coil-shaped hierarchical structure. The developed artificial muscle provides an average actuation speed of approximate to 5.2% s(-1) at expansion and approximate to 3.1% s(-1) at contraction cycles, being the fastest amongst previously demonstrated actuators of similar type. It is demonstrated that these muscle yarns can autonomously close a window in wet climates. The building block yarns are washable without any material degradation, making them suitable for smart, reusable textile and soft robotic devices.
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| 3. |
- Bolin, Maria, et al.
(författare)
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Active Control of Epithelial Cell-Density Gradients Grown Along the Channel of an Organic Electrochemical Transistor
- 2009
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Ingår i: ADVANCED MATERIALS. - : Wiley. - 0935-9648 .- 1521-4095. ; 21:43, s. 4379-
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Tidskriftsartikel (refereegranskat)abstract
- Complex patterning of the extracellular matrix, cells, and tissues under in situ electronic control is the aim of the technique presented here. The distribution of epithelial cells along the channel of an organic electrochemical transistor is shown to be actively controlled by the gate and drain voltages, as electrochemical gradients are formed along the transistor channel when the device is biased.
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| 4. |
- Cao, Danfeng, 1991-, et al.
(författare)
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Biohybrid Variable-Stiffness Soft Actuators that Self-Create Bone
- 2022
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Ingår i: Advanced Materials. - Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA. - 0935-9648 .- 1521-4095. ; 34:8
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Tidskriftsartikel (refereegranskat)abstract
- Inspired by the dynamic process of initial bone development, in which a soft tissue turns into a solid load-bearing structure, the fabrication, optimization, and characterization of bioinduced variable-stiffness actuators that can morph in various shapes and change their properties from soft to rigid are hereby presented. Bilayer devices are prepared by combining the electromechanically active properties of polypyrrole with the compliant behavior of alginate gels that are uniquely functionalized with cell-derived plasma membrane nanofragments (PMNFs), previously shown to mineralize within 2 days, which promotes the mineralization in the gel layer to achieve the soft to stiff change by growing their own bone. The mineralized actuator shows an evident frozen state compared to the movement before mineralization. Next, patterned devices show programmed directional and fixated morphing. These variable-stiffness devices can wrap around and, after the PMNF-induced mineralization in and on the gel layer, adhere and integrate onto bone tissue. The developed biohybrid variable-stiffness actuators can be used in soft (micro-)robotics and as potential tools for bone repair or bone tissue engineering.
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| 5. |
- Mashayekhi Mazar, Fariba, et al.
(författare)
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Artificial Muscles Powered by Glucose
- 2019
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 31:32
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Tidskriftsartikel (refereegranskat)abstract
- Untethered actuation is important for robotic devices to achieve autonomous motion, which is typically enabled by using batteries. Using enzymes to provide the required electrical charge is particularly interesting as it will enable direct harvesting of fuel components from a surrounding fluid. Here, a soft artificial muscle is presented, which uses the biofuel glucose in the presence of oxygen. Glucose oxidase and laccase enzymes integrated in the actuator catalytically convert glucose and oxygen into electrical power that in turn is converted into movement by the electroactive polymer polypyrrole causing the actuator to bend. The integrated bioelectrode pair shows a maximum open-circuit voltage of 0.70 +/- 0.04 V at room temperature and a maximum power density of 0.27 mu W cm(-2) at 0.50 V, sufficient to drive an external polypyrrole-based trilayer artificial muscle. Next, the enzymes are fully integrated into the artificial muscle, resulting in an autonomously powered actuator that can bend reversibly in both directions driven by glucose and O-2 only. This autonomously powered artificial muscle can be of great interest for soft (micro-)robotics and implantable or ingestible medical devices manoeuvring throughout the body, for devices in regenerative medicine, wearables, and environmental monitoring devices operating autonomously in aqueous environments.
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| 6. |
- Melling, Daniel, et al.
(författare)
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Conjugated Polymer Actuators and Devices: Progress and Opportunities
- 2019
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 31:22
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Forskningsöversikt (refereegranskat)abstract
- Conjugated polymers (CPs), as exemplified by polypyrrole, are intrinsically conducting polymers with potential for development as soft actuators or artificial muscles for numerous applications. Significant progress has been made in the understanding of these materials and the actuation mechanisms, aided by the development of physical and electrochemical models. Current research is focused on developing applications utilizing the advantages that CP actuators have (e.g., low driving potential and easy to miniaturize) over other actuating materials and on developing ways of overcoming their inherent limitations. CP actuators are available as films, filaments/yarns, and textiles, operating in liquids as well as in air, ready for use by engineers. Here, the milestones made in understanding these unique materials and their development as actuators are highlighted. The primary focus is on the recent progress, developments, applications, and future opportunities for improvement and exploitation of these materials, which possess a wealth of multifunctional properties.
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| 7. |
- Persson, Kristin M, et al.
(författare)
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Electronic control of cell detachment using a self-doped conducting polymer
- 2011
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Ingår i: Advanced Materials. - : Wiley-Blackwell. - 0935-9648 .- 1521-4095. ; 23:38, s. 4403-4408
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Tidskriftsartikel (refereegranskat)abstract
- An electronic detachment technology based on thin films of a poly(3,4-ethylene-dioxythiophene) derivative is evaluated for controlled release of human epithelial cells. When applying a potential of 1 V, the redox-responsive polymer films detach and disintegrate and at the same time release cells cultured on top in the absence of any enzymatic treatment with excellent preservation of membrane proteins and cell viability.
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| 8. |
- Tybrandt, Klas, et al.
(författare)
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Translating Electronic Currents to Precise Acetylcholine-Induced Neuronal Signaling Using an Organic Electrophoretic Delivery Device
- 2009
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 21:44, s. 4442-
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Tidskriftsartikel (refereegranskat)abstract
- A miniaturized organic electronic ion pump (OEIP) based on conjugated polymers is developed for delivery of positively charged biomolecules. Characterization shows that applied voltage can precisely modulate the delivery rate of the neurotransmitter acetylcholine. The capability of the device is demonstrated by convection-free, spatiotemporally resolved delivery of acetylcholine via a 10 mu m channel for dynamic stimulation of single neuronal cells.
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| 9. |
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