Browsing by Subject "Driving forces"

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Open Access
Glucose sensors based on electrospun nanofibers: a review
(Springer Verlag, 2016) Senthamizhan, A.; Balusamy, B.; Uyar, Tamer
The worldwide increase in the number of people suffering from diabetes has been the driving force for the development of glucose sensors. The recent past has devised various approaches to formulate glucose sensors using various nanostructure materials. This review presents a combined survey of these various approaches, with emphasis on the current progress in the use of electrospun nanofibers and their composites. Outstanding characteristics of electrospun nanofibers, including high surface area, porosity, flexibility, cost effectiveness, and portable nature, make them a good choice for sensor applications. Particularly, their nature of possessing a high surface area makes them the right fit for large immobilization sites, resulting in increased interaction with analytes. Thus, these electrospun nanofiber-based glucose sensors present a number of advantages, including increased life time, which is greatly needed for practical applications. Taking all these facts into consideration, we have highlighted the latest significant developments in the field of glucose sensors across diverse approaches.
Open Access
Photopatterning of PMMA films with gold nanoparticles: diffusion of AuCl4-ions
(2010) Yilmaz, E.; Ertas, G.; Bengu, E.; Süzer, Şefik
Photopatterning of poly(methyl methacrylate) (PMMA) films is performed by UV irradiation of the polymer films containing uniformly distributed AuCl 4 - ions. The process reduces the gold ions and leads to production of Au nanoparticles in the irradiated regions at room temperature (RT). Resulting films are investigated with scanning electron microscopy, which revealed, in addition to regions with gold nanoparticles, the presence of "ion-depleted regions". These regions are formed at RT and within the rigid polymer matrix by diffusion of gold ions toward the irradiated regions, ending up with no or very little gold moieties, which are important for prevention of delayed processes for postgeneration of unwanted features, if and when such materials are utilized for device production. Further investigations performed by fluorescence and Raman measurements and XPS mapping give additional evidence supporting the existence of such regions. Similar regions are also observed within the poly(vinyl alcohol) (PVAL) films. The ion-depleted regions are about 10 μm wide, which is a significant length for the metal ions to travel through a rigid matrix like PMMA (or PVAL) at room temperature and raises important questions as to the diffusion mechanism(s) of the metal ions and to the nature of the driving force(s).
Open Access
Reactive footstep planning for a planar spring mass hopper
(IEEE, 2009-10) Arslan, Ömür; Saranlı, Uluç; Morgül, Ömer
The main driving force behind research on legged robots has always been their potential for high performance locomotion on rough terrain and the outdoors. Nevertheless, most existing control algorithms for such robots either make rigid assumptions about their environments (e.g flat ground), or rely on kinematic planning at low speeds. Moreover, the traditional separation of planning from control often has negative impact on the robustness of the system against model uncertainty and environment noise. In this paper, we introduce a new method for dynamic, fully reactive footstep planning for a simplified planar spring-mass hopper, a frequently used model for running behaviors. Our approach is based on a careful characterization of the model dynamics and an associated deadbeat controller, used within a sequential composition framework. This yields a purely reactive controller with a very large, nearly global domain of attraction that requires no explicit replanning during execution. Finally, we use a simplified hopper in simulation to illustrate the performance of the planner under different rough terrain scenarios and show that it is extremely robust to both model uncertainty and measurement noise. © 2009 IEEE.