Development and Characterization of Electrospun Composites Built on Polycaprolactone and Cerium-Containing Phases.

The current study reports on the fabrication of composite scaffolds based on polycaprolactone (PCL) and cerium (Ce)-containing powders, followed by their characterization from compositional, structural, morphological, optical and biological points of view. First, CeO, Ce-doped calcium phosphates and Ce-substituted bioglass were synthesized by wet-chemistry methods (precipitation/coprecipitation and sol-gel) and subsequently loaded on PCL fibres processed by electrospinning. The powders were proven to be nanometric or micrometric, while the investigation of their phase composition showed that Ce was present as a dopant within the crystal lattice of the obtained calcium phosphates or as crystalline domains inside the glassy matrix.

Bioinspired polypyrrole based fibrillary artificial muscle with actuation and intrinsic sensing capabilities.

A non-conventional, bioinspired device based on polypyrrole coated electrospun fibrous microstructures, which simultaneously works as artificial muscle and mechanical sensor is reported. Fibrous morphology is preferred due to its high active surface which can improve the actuation/sensing properties, its preparation still being challenging. Thus, a simple fabrication algorithm based on electrospinning, sputtering deposition and electrochemical polymerization produced electroactive aligned ribbon meshes with analogous characteristics as natural muscle fibers.

Direct and remote induced actuation in artificial muscles based on electrospun fiber networks.

The present work reports a new configuration of soft artificial muscle based on a web of metal covered nylon 6/6 micrometric fibers attached to a thin polydimethylsiloxane (PDMS) film. The preparation process is simple and implies the attachment of metalized fiber networks to a PDMS sheet substrate while heating and applying compression. The resulting composite is versatile and can be cut in different shapes as a function of the application sought.

Fabrication of ZnO and TiO Nanotubes via Flexible Electro-Spun Nanofibers for Photocatalytic Applications.

Web-like architectures of ZnO and TiO nanotubes were fabricated based on a three-step process of templating polymer nanofibers produced by electrospinning (step 1). The electrospun polymer nanofibers were covered by radio-frequency magnetron sputtering with thin layers of semiconducting materials (step 2), with FESEM observations proving uniform deposits over their entire surface. ZnO or TiO nanotubes were obtained by subsequent calcination (step 3).

PCL-ZnO/TiO/HAp Electrospun Composite Fibers with Applications in Tissue Engineering.

The main objective of the tissue engineering field is to regenerate the damaged parts of the body by developing biological substitutes that maintain, restore, or improve original tissue function. In this context, by using the electrospinning technique, composite scaffolds based on polycaprolactone (PCL) and inorganic powders were successfully obtained, namely: zinc oxide (ZnO), titanium dioxide (TiO) and hydroxyapatite (HAp). The novelty of this approach consists in the production of fibrous membranes based on a biodegradable polymer and loaded with different types of mineral powders, each of them having a particular function in the resulting composite.

Palladium/palladium oxide coated electrospun fibers for wearable sweat pH-sensors.

The work describes the development of a flexible, hydrogel embedded pH-sensor that can be integrated in inexpensive wearable and non-invasive devices at epidermal level for electrochemical quantification of H ions in sweat. Such a device can be useful for swift, real time diagnosis and for monitoring specific conditions. The sensors' working electrodes are flexible poly(methyl methacrylate) electrospun fibers coated with a thin gold layer and electrochemically functionalized with nanostructured palladium/palladium oxide.

White-Light Emission of Dye-Doped Polymer Submicronic Fibers Produced by Electrospinning.

Lighting and display technologies are evolving at tremendous rates nowadays; new device architectures based on new, microscopic building blocks are being developed. Besides high light-emission efficiencies, qualities including low cost, low environmental impact, flexibility, or lightweightness are sought for developing new types of devices. Electrospun polymer fibers represent an interesting type of such microscopic structures that can be employed in developing new functionalities.

Flexible Delivery Patch Systems based on Thermoresponsive Hydrogels and Submicronic Fiber Heaters.

This paper proposes a novel, flexible, low cost administration patch which could be used as a non-invasive, controlled transdermal drug delivery system. The fabricated device consists in a flexible microfiber architecture heater covered with a thermoresponsive hydrogel, namely poly(N-isopropylacrylamide), as a matrix for the incorporation of active molecules. The manufacturing process consists of two main steps.

Polypyrrole Actuator Based on Electrospun Microribbons.

The development of soft actuators by using inexpensive raw materials and straightforward fabrication techniques, aiming at creating and developing muscle like micromanipulators, represents an important challenge nowadays. Providing such devices with biomimetic qualities, for example, sensing different external stimuli, adds even more complexity to the task. We developed electroactive polymer-coated microribbons that undergo conformational changes in response to external physical and chemical parameters.

Direct and contactless electrical control of temperature of paper and textile foldable substrates using electrospun metallic-web transparent electrodes.

Multiple and complex functionalities are a demand nowadays for almost all materials, including common day-to-day materials such as paper, textiles, wood, etc. In the present report, the surface temperature control of different types of materials, including paper and textiles, was demonstrated by Joule heating of metallic-web transparent electrodes both by direct current and by RF induced eddy currents. Polymeric submicronic fiber webs were prepared by electrospinning, and metal sputtering was subsequently performed to transform them into flexible transparent electrodes.

Electrochromic properties of polyaniline-coated fiber webs for tissue engineering applications.

By combining the electrospinning method advantages (high surface-to-volume ratio, controlled morphology, varied composition and flexibility for the resulting structures) with the electrical activity of polyaniline, a new core-shell-type material with potential applications in the field of artificial muscles was synthesized. Thus, a poly(methylmethacrylate) solution was electrospun in optimized conditions to obtain randomly oriented polymer fiber webs. Further, a gold layer was sputtered on their surface in order to make them conductive and improve the mechanical properties.