Autonomous decision making in a bioinspired adaptive robotic anchoring module

This paper proposes a bioinspired adaptive anchoring module that can be integrated into robots to enhance their mobility and manipulation abilities. The design of the module is inspired by the structure of the mouth in Chilean lamprey (Mordacia lapicida) where a combination of suction and several arrays of teeth with different sizes around the mouth opening is used for catching preys and anchoring onto them. The module can deploy a suitable mode of attachment, via teeth or vacuum suction, to different contact surfaces in response to the textural properties of those surfaces. In order to make a decision on the suitable mode of attachment, an original dataset of 500 images of outdoor and indoor surfaces was used to train a visual surface examination model using YOLOv3; a virtually real-time object detection algorithm. The mean average precision of the trained model was calculated to be 91%. We have conducted a series of pull-out tests to characterize the module’s strength of attachments. The results of the experiments indicate that the anchoring module can withstand an applied detachment force of up to 70N and 30N when attached using teeth and vacuum suction, respectively

A Framework for the Symmetric Generalisation of the Miura-ori

The Miura fold pattern, or the Miura-ori, is a flat-foldable origami tessellation which has been applied to the folding of deployable structures for various engineering and architectural applications. In recent years, researchers have proposed systematic (see, e.g., [1] or [2]), and also free-form [3], variations on the Miura pattern. This paper develops a geometric framework for the symmetric generalisation of the Miura-ori while preserving the ‘stacking while folding’ behaviour of the pattern. We present a number of novel concepts and definitions which help us apply systematic variations on the original pattern. We study the Miura crease pattern as a pmg wallpaper pattern which is one of the seventeen distinct wallpaper groups. We reduce the symmetry of the Miura-ori to obtain new patterns while preserving the flat-foldability condition at each node. We conclude that we are able to use the Miura-ori, which is a globally planar pattern in its partially folded states, to systematically design either ‘globally planar’ or ‘globally curved’ patterns, through appropriate design variations on the original pattern. </jats:p

Roughening transition as a driving factor in the formation of self-ordered one-dimensional nanostructures

Based on the Monte Carlo kinetic method, we investigated the formation mechanisms of periodical modulations arising along the length of one-dimensional structures. The evolution of initially cylindrical nanowires/slabs at temperatures lower than their respective melting temperatures can result either in breakup into single nanoclusters or in the formation of stable states with pronounced modulations of cross section. Such configurations, observed in a number of experiments, are excited at wavelengths that are below the critical value for the development of classical Rayleigh instability. We show that the modulation excited in the subcritical mode corresponds to the appearance of roughening transition on the quasi-one-dimensional surface of nanowires/slabs. Since the arise of roughening transition is possible only on certain facets of metals with a given crystal structure, the short-wavelength modulations of one-dimensional systems, as shown in our work, can be realized (i) with the proper orientation of the nanowire/slab axis providing spontaneous appearance of roughening transition on its lateral surface, (ii) by the method of activating the surface diffusion of atoms by external impact (irradiation with an electron beam or contact with a cold plasma), which stimulates roughening transition without significant heating of the nanowire. The results obtained for the cases of BCC and FCC lattices can be used in the controlled synthesis of ordered one-dimensional structures for use in optoelectronics and in ultra-large-scale integrated circuits