Methods and Applications of Multilayer Silk Fibroin Laminates Based on Spatially Controlled Welding in Protein Films

Recent use of biopolymers as interface materials between planar, inorganic electronics and biological tissues has required the adaptation of micro‐ and nanofabrication techniques for use with these nontraditional materials. In this work, a method which builds on this principle for spatial control of adhesion in multilayer silk fibroin laminates is investigated. This is accomplished through the addition of a spatially patterned amorphous silk adhesive layer in between the films to be adhered, before thermally processing them with heat (120 °C) and pressure (80 Psi) according to established procedures. A one‐step method for rapid, high‐throughput fabrication is demonstrated, which establishes a strong (1100 kPa) bond between the layers independent of the initial processing conditions of the films. The adhesive layers can be patterned using existing silk fabrication techniques, allowing for the assembly of complex geometries including bilayers and microbubbles. Additionally, the utility of this method is demonstrated for potential applications in drug delivery and transient electronics. This approach provides a versatile method for construction of complex multilayer structures in silk, which with future work may ultimately improve the utility of this material as a bridge between high technology and the biomedical sciences.     

Water and Sewage Service Quality: A Proposal of a New Multi-Questionnaire Monitoring Tool

The measurement of a service Quality is a relevant issue for organizations. In this paper we describe an application of the Parasuraman, Zeithalm and Berry’s (PZB) conceptual model of service Quality in the field of the water and sewage service. The PZB model determinants have been specialized for this specific target and a multi-questionnaire has been developed. This activity has been developed basing on Quality Function Deployment methodology. The described approach is structured into two parts. The first one concerns a general evaluation of the service Quality, while the second one considers specific service aspects enabling to better understand possible reasons of dissatisfaction. A specific software application to support data collection and statistical analysis is described. The proposed monitoring tool ensures an overall evaluation of service Quality from the customer point of view. Its organization into two parts allows reducing the overall costs of data acquisition as well as maximizing the information got from customers. The multi-questionnaire can be tailored in order to meet the needs of both customers and service controller in the monitored areas. The results of the survey show the perceived Quality of the service. Future work will be focused on the comparison between the customers’ perceptions and the Quality which is actually assured by the service provider (the offered Quality).     

Short-term effects of non-competitive funding to single academic researchers

Scientometrics - Research funding is essential to promote the scientific activity of researchers and the dissemination of their results. Simplifying, funding schemes can be classified in two...     

Transdermal Delivery Devices: Fabrication,Mechanics and Drug Release from Silk

Microneedles are a relatively simple, minimally invasive and painless approach to deliver drugs across the skin. However, there remain limitations with this approach because of the materials most commonly utilized for such systems. Silk protein, with tunable and biocompatibility properties, is a useful biomaterial to overcome the current limitations with microneedles. Silk devices preserve drug activity, offer superior mechanical properties and biocompatibility, can be tuned for biodegradability, and can be processed under aqueous, benign conditions. In the present work, the fabrication of dense microneedle arrays from silk with different drug release kinetics is reported. The mechanical properties of the microneedle patches are tuned by post‐fabrication treatments or by loading the needles with silk microparticles, to increase capacity and mechanical strength. Drug release is further enhanced by the encapsulation of the drugs in the silk matrix and coating with a thin dissolvable drug layer. The microneedles are used on human cadaver skin and drugs are delivered successfully. The various attributes demonstrated suggest that silk‐based microneedle devices can provide significant benefit as a platform material for transdermal drug delivery.     

Functionalized‐Silk‐Based Active Optofluidic Devices

Silk protein from the silkworm Bombyx mori has excellent chemical and mechanical stability, biocompatibility, and optical properties. Additionally, when the protein is purified and reformed into materials, the biochemical functions of dopants entrained in the protein matrix are stabilized and retained. This unique combination of properties make silk a useful multifunctional material platform for the development of sensor devices. An approach to increase the functions of silk‐based devices through chemical modifications to demonstrate an active optofluidic device to sense pH is presented. Silk protein is chemically modified with 4‐aminobenzoic acid to add spectral‐color‐responsive pH sensitivity. The functionalized silk is combined with the elastomer poly(dimethyl siloxane) in a single microfluidic device. The microfluidic device allows spatial and temporal control of the delivery of analytic solutions to the system to provide the optical response of the optofluidic device. The modified silk is stable and spectrally responsive over a wide pH range from alkaline to acidic.     

Materials and designs for wirelessly powered implantable light-emitting systems

Strategies are presented to achieve bendable and stretchable systems of microscale inorganic light-emitting diodes with wireless powering schemes, suitable for use in implantable devices. The results include materials strategies, together with studies of the mechanical, electronic, thermal and radio frequency behaviors both in vitro and in in-vivo animal experiments.