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Now showing 1 - 3 of 3
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    Fingertip friction and tactile rating of wrapping papers
    (Berlin ; Heidelberg : Springer, 2022) Jost, Kim Michèle; Drewing, Knut; Bennewitz, Roland; Seifi, Hasti; Kappers, Astrid M. L.; Schneider, Oliver; Drewing, Knut; Pacchierotti, Claudio; Abbasimoshaei, Alireza; Huisman, Gijs; Kern, Thorsten A.
    The tactile exploration and perception of wrapping papers is investigated in terms of fingertip friction and rating of sensory, affective, and evaluative adjectives. Friction coefficients, which vary significantly between samples, are correlated with factors such as valence which are identified in a principal component analysis of subjective ratings. We found that affective appraisals of valence and arousal as well as evaluations of novelty, but not of value, decreased with increasing friction.
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    Like a Second Skin: Understanding How Epidermal Devices Affect Human Tactile Perception
    (New York,NY,United States : Association for Computing Machinery, 2019) Nittala, Aditya Shekhar; Kruttwig, Klaus; Lee, Jaeyeon; Bennewitz, Roland; Arzt, Eduard; Steimle, Jürgen; Brewster, Stephen
    The emerging class of epidermal devices opens up new opportunities for skin-based sensing, computing, and interaction. Future design of these devices requires an understanding of how skin-worn devices affect the natural tactile perception. In this study, we approach this research challenge by proposing a novel classification system for epidermal devices based on flexural rigidity and by testing advanced adhesive materials, including tattoo paper and thin films of poly (dimethylsiloxane) (PDMS). We report on the results of three psychophysical experiments that investigated the effect of epidermal devices of different rigidity on passive and active tactile perception. We analyzed human tactile sensitivity thresholds, two-point discrimination thresholds, and roughness discrimination abilities on three different body locations (fingertip, hand, forearm). Generally, a correlation was found between device rigidity and tactile sensitivity thresholds as well as roughness discrimination ability. Surprisingly, thin epidermal devices based on PDMS with a hundred times the rigidity of commonly used tattoo paper resulted in comparable levels of tactile acuity. The material offers the benefit of increased robustness against wear and the option to re-use the device. Based on our findings, we derive design recommendations for epidermal devices that combine tactile perception with device robustness.
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    Perception of Friction in Tactile Exploration of Micro-structured Rubber Samples
    (Berlin ; Heidelberg : Springer, 2022) Fehlberg, Maja; Kim, Kwang-Seop; Drewing, Knut; Hensel, René; Bennewitz, Roland; Seifi, Hasti; Kappers, Astrid M. L.; Schneider, Oliver; Drewing, Knut; Pacchierotti, Claudio; Abbasimoshaei, Alireza; Huisman, Gijs; Kern, Thorsten A.
    Fingertip friction and the related shear of skin are key mechanical mechanisms in tactile perception, but the perception of friction itself is rarely explored except for the flat surfaces of tactile displays. We investigated the perception of friction for tactile exploration of a unique set of samples whose fabric-like surfaces are equipped with regular arrays of flexible micropillars. The measured fingertip friction increases with decreasing bending stiffness, where the latter is controlled by radius (20–75 µm) and aspect ratio of the micropillars. In forced-choice tasks, participants noticed relative differences in friction as small as 0.2, and even smaller when a sample with less than 100 µm distance between pillars is omitted from the analysis. In an affective ranking of samples upon active touch, the perception of pleasantness is anticorrelated with the measured friction. Our results offer insights towards a rational design of materials with well-controlled surface microstructure which elicit a dedicated tactile appeal.