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End date: 2019 × Start date: 2016 × DDC: 530 × Publisher: Milton Park : Taylor & Francis × WGL Institute: INM ×

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Now showing 1 - 2 of 2
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    A study of the adhesive foot of the gecko: Translation of a publication by Franz Weitlaner
    (Milton Park : Taylor & Francis, 2015) Kroner, Elmar; Davis, Chelsea S.
    In recent years, hundreds of scientific studies have been published regarding gecko-inspired adhesives. The primary reason for this increasing interest lies in the unique properties which are combined in the adhesive system of the gecko: this natural system can quickly and repeatedly adhere to different surface chemistry and roughness without the use of adhesion-mediating fluids. Although these properties seem to be inconspicuous at first, there is no man-made system currently available which successfully combines all of these properties and competes with the biological adhesive system. However, there are many applications which may benefit from an artificial adhesion system inspired by geckos, ranging from climbing robots and handling systems to biomedical patches and household objects.
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    Discharge during detachment of micro-structured PDMS sheds light on the role of electrostatics in adhesion
    (Milton Park : Taylor & Francis, 2012) Brörmann, Katrin; Burger, Karin; Jagota, Anand; Bennewitz, Roland
    Light emission due to discharge in air is detected during and after the detachment of microstructured PDMS samples from glass surfaces, showing contact charging of the surfaces. The light emission provides information about the detachment process, like the velocity of the peeling front, which is difficult to obtain otherwise. While the work of separation exhibits the dependence on pulling velocity typically found for viscoelastic materials, the emission intensity exhibits almost no velocity dependence. We present a model for the rate-dependent contribution of a mosaic of contact charges to the work of separation. Also, the work of separation increases as expected with increasing aspect ratio of the microstructure, while the emission intensity shows a maximum for intermediate structures. Based on their different dependencies and on an upper-bound estimate of the energy emitted as light, we conclude that for the given system the contribution of electrostatic attraction to the work of separation is minor.