Theoretical investigations on the behavior of artificial sensors for surface texture detection. - In: Dynamical systems in theoretical perspective, (2018), S. 311-321
Animal vibrissae are used as natural inspiration for artificial tactile sensors, e.g., the mystacial vibrissae enable rodents to perform several tasks in using these tactile hairs: object shape determination and surface texture discrimination. Referring to the literature, the Kinetic Signature Hypothesis states that the surface texture detection is a highly dynamic process. It is assumed that the animals gather information about the surface texture out of a spatial, temporal pattern of kinetic events. This process has to be analyzed in detail to develop an artificial tactile sensor with similar functionalities. Hence, we set up a mechanical model for theoretical investigations of the process. This model is analyzed in two different directions using numerical simulations: at first a quasi-static and then a fully dynamic description.
https://doi.org/10.1007/978-3-319-96598-7_25
Properties of polydimethylsiloxane and magnetoactive polymers with electroconductive particles. - In: Macromolecular chemistry and physics, ISSN 1521-3935, Bd. 219 (2018), 18, S. 1800222, insges. 8 S.
Magnetoactive polymers are intelligent materials whose mechanical and electrical characteristics are reversibly influenced by external magnetic stimuli. They consist of a highly elastic polymer matrix in which magnetically soft and/or hard particles are distributed by means of special fabrication processes. In addition to ferromagnetic particles such as carbonyl iron powder, electrically conductive particles may also be embedded into the polymer matrix. After characterizing a range of compounds, this work focuses on a comparison of the electrical properties and the suitability of various materials for applications, with particular emphasis on integration into 3D and 6D printing processes. 6D printing is based on the selective positioning of particles in a 3D polymer matrix with a further three degrees of freedom for a graduated dispersion of the particles at certain points and in desired directions. The aim is therefore to ensure that the polymers containing electroconductive tracks have the best possible electrical properties, that is, low resistivity but are still capable of being printed. A comparison between the traditionally used compounds containing graphite and carbon black is made for the first time. This latter is found to be greatly superior both in terms of electrical conductivity and applicability to 3D printing and 6D printing.
https://doi.org/10.1002/macp.201800222
Periodic locomotion of a two-body crawling system along a straight line on a rough inclined plane. - In: ZAMM, ISSN 1521-4001, Bd. 98 (2018), 11, S. 1930-1946
The motion of a two-body limbless crawler along a line of maximum slope on an inclined plane is considered. Dry friction (anisotropic in the general case) acts between the system's bodies and the underlying plane. The motion is excited and controlled by a periodic change in the distance between the bodies. Of most interest is the periodic upward motion of the system, when the velocity of the system's center of mass changes periodically with a period coinciding with that of the excitation. A mathematical model of the crawler is presented. An upper bound for the inclination angles of the plane at which the system can move upward is estimated. This estimate is based on the averaged model, which implies smallness of the coefficient of friction. Numerical and physical simulation is performed to verify the theoretical results and define an applicability area for them.
https://doi.org/10.1002/zamm.201800107
An approach to the estimation of the actuation parameters for mobile tensegrity robots with tilting movement sequences. - In: 2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2018), ISBN 978-1-5386-6380-6, (2018), insges. 8 S.
https://doi.org/10.1109/REMAR.2018.8449871
Adaptive soft robotic gripper based on shape morphing compliant system. - In: 2018 International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2018), ISBN 978-1-5386-6380-6, (2018), insges. 10 S.
This paper presents a new shape morphing compliant system - a shape morphing compliant structure with integrated actuators and sensors - for application as an adaptive soft robotic gripper. In many of today industries, there is a need to grasp differently shaped and sized objects as well as objects of a different stiffness or very soft objects. Classical rigid-body based grippers cannot safely manipulate such a wide variety of objects, as they are stiff and not adaptive. By integrating actuators within a compliant structure or mechanism, it is possible to develop an adaptive soft gripper that can achieve multiple shapes of its grasping surface i.e. different grasping patterns. Such gripper would be able to adapt its shape to different shaped objects and to realize safe grasping. By additionally integrating sensors, a compliant system results and the gripper can detect contact with objects. Via developed controller and actuators, appropriate shape morphing of its grasping surface can be realised. The concept of a two-finger gripper and a functional model of one gripper finger are presented in the paper. Actuators are formed by using shape memory alloy wire nitinol and sensors are formed by using conductive graphite foam. It will be shown that developed compliant system can realize an adaptive soft gripper finger with different grasping shapes. The control algorithm for the gripper finger is developed as well and it will be demonstrated that the gripper finger can decide which actuator needs to be activated in order to achieve appropriate shape morphing. The presented adaptive soft gripper structure can have many potential applications in robotics.
https://doi.org/10.1109/REMAR.2018.8449831
Investigations of the geometrical scaling in the systematic synthesis of compliant mechanisms. - In: Proceedings of the 18th International Conference of the European Society for Precision Engineering and Nanotechnology, (2018), S. 67-68
Object shape recognition and reconstruction using pivoted tactile sensors. - In: Mathematical problems in engineering, ISSN 1563-5147, (2018), Article ID 1613945, insges. 11 S.
https://doi.org/10.1155/2018/1613945
BDNF-producing human mesenchymal stem cells in an alginate-matrix: neuroprotection and cochlear implant coating stability in vitro. - In: Laryngo-Rhino-Otologie, ISSN 1438-8685, Bd. 97 (2018), S 02, S388, insges. 1 S.
https://doi.org/10.1055/s-0038-1641059
Über den Vorteil sehr langsamer Insertionsgeschwindigkeit: niedrigere Insertionskräfte bei Cochlea-Implantaten :
On the benefit of ultra-slow insertion speed: reduced insertion forces in cochlear implantation surgery. - In: Laryngo-Rhino-Otologie, ISSN 1438-8685, Bd. 97 (2018), S 02, S239, insges. 1 S.
https://doi.org/10.1055/s-0038-1640541
On precise modelling of very thin flexure hinges. - In: Proceedings of the 18th International Conference of the European Society for Precision Engineering and Nanotechnology, (2018), S. 87-88
The continuously rising demands for precision favour the application of monolithic compliant mechanisms with flexure hinges in various fields of precision engineering. It gives way to an almost frictionless and precise motion even under vacuum conditions. These advantages have made compliant mechanism an integral component of high precision weighing cells. A downside of compliant joints is their stiffness towards deflection, which limits the sensitivity of the overall system. Consequently, the flexure hinges are manufactured as thin as possible. The present limit in terms of manufacturing technology is within the range of 50 [my]m. The objective of predicting the behaviour of highest precision weighing cells by modelling is directly interconnected with the exact knowledge of the behaviour of flexure hinges in terms of stiffness. Especially, for flexure hinges with high aspect ratios, typically found in weighing cells, the existing analytical equations and finite element models show pronounced deviations. The present research effort is dedicated to a clarification of this observation. Structure mechanical finite element models are developed to identify the deviations of the models precisely. Results obtained are compared to analytical results and conclusions for the modelling of thin flexure hinges are drawn.