Mechanical Intelligence (MI): A Bioinspired Concept for Transforming Engineering Design

Despite significant scientific advances in the past decades, most structures around us are static and ironically outdated from a technological perspective. Static structures have limited efficiency and durability and typically perform only a single task. Adaptive structures, in contrast, adjust to different conditions, tasks, and functions. They not only offer multi-functionality but also enhanced efficiency and durability. Despite their obvious advantages over conventional structures, adaptive structures have only been limitedly used in everyday life applications. This is because adaptive structures often require sophisticated sensing, feedback, and controls, which make them costly, heavy, and complicated. To overcome this problem, here the concept of Mechanical Intelligence (MI) is introduced to promote the development of engineering systems that adapt to circumstances in a passive-automatic way. MI will offer a new paradigm for designing structural components with superior capabilities. As adaptability has been rewarded throughout evolution, nature provides one of the richest sources of inspiration for developing adaptive structures. MI explores nature-inspired mechanisms for automatic adaptability and translates them into a new generation of mechanically intelligent components. MI structures, presenting widely accessible bioinspired solutions for adaptability, will facilitate more inclusive and sustainable industrial development, reflective of Goal 9 of the 2030 Agenda for Sustainable Development

Effect of sample treatment on the elastic modulus of locust cuticle obtained by nanoindentation

Cuticle is one of the most abundant, but least studied, biological composites. As a result, it has contributed very little to the field of biomimetics. An important step to overcome this problem is to study cuticle biomechanics by means of accurate mechanical measurements. However, due to many reasons, mechanical testing on fresh cuticle specimens is not always possible. Hence, researchers often use stored specimens to measure properties of arthropod cuticle. Our knowledge about the influence of different treatment methods on cuticle properties is currently very limited. In this study, we investigated the effect of freezing, desiccation, and rehydration on the elastic modulus of the hind tibial cuticle of locusts obtained by nanoindentation. We found that all the mentioned treatments significantly influence cuticle properties. This is in contrast to previous reports suggesting that freezing did not significantly influence the elastic modulus of native cuticle specimens tested in bending. In the light of our data, we suggest that changes of the elastic modulus of cuticle are not solely due to changes of the water content. Our results provide a platform for more accurate measurements of cuticle properties

Performance evaluation of FBP reconstruction in SPECT Imaging

Abstract Introduction: The purpose of this study was to define an optimal parameter for the tomographic reconstruction procedure in routine single photon emission tomography (SPECT) studies. In this study Hoffman Brain Phantom is modified in such a way that only software capability is evaluated. The phantom is composed of several independent slice that can be imaged individually (planar) or in 3-D composition (SPECT). Method and Materials: Planar image of the slices were imaged separately. The tomographic image was ..

The Spectroscopic Orbits of Five Solar Type, Single Lined Binaries

We have determined spectroscopic orbits for five single-lined spectroscopic binaries, HD 100167, HD 135991, HD 140667, HD 158222, HD 217924. Their periods range from 60.6 to 2403 days and the eccentricities, from 0.20 to 0.84. Our spectral classes for the stars confirm that they are of solar type, F9 to G5, and all are dwarfs. Their [Fe/H] abundances, determined spectroscopically, are close to the solar value and on average are 0.12 greater than abundances from a photometric calibration. Four of the five stars are rotating faster than their predicted pseudosynchronous rotational velocities.Comment: 12 pages emulateap

Conflicting requirements for transparency and mechanical stability in the compound eyes of desert locusts

Compound eyes of insects should be both thin and transparent to allow light to pass through, and at the same time mechanically stable to serve as exoskeleton. These conflicting requirements make the corneal cuticle an interesting example for studying cuticle biomechanics as well as for designing composite materials that seek similar properties. Here we combined scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and nanoindentation, to investigate the microstructure, material composition and material properties of the corneal cuticle of desert locust Schistocerca gregaria. The results suggest that a fully helicoidal architecture and large proportion of resilin in the corneal cuticle are likely to be adaptations for light transmission. Even though the corneal cuticle is resilin-rich, its elastic modulus is at least three times higher than that previously reported for other resilin-rich cuticles. This is likely due to the specific microstructure of the corneal cuticle with densely packed layers. This study presents one of a series of studies, in which we used multidisciplinary approaches, to understand the link between the structure, material, property, and function in insect cuticle

Double‐spirals offer the development of pre‐programmable modular metastructures

Metamaterials with adjustable, sometimes unusual properties offer advantages over conventional materials with predefined mechanical properties in many technological applications. A group of metamaterials, called modular metamaterials or metastructures, are developed through the arrangement of multiple, mostly similar building blocks. These modular structures can be assembled using prefabricated modules and reconfigured to promote efficiency and functionality. Here, we developed a novel modular metastructure by taking advantage of the high compliance of pre-programmable double-spirals. First, we simulated the mechanical behavior of a four-module metastructure under tension, compression, rotation, and sliding using the finite-element method. Then, we used 3D printing and mechanical testing to illustrate the tunable anisotropic and asymmetric behavior of spiral-based metastructures in practice. Our results show the simple reconfiguration of the presented metastructure toward the desired functions. The mechanical behavior of single double-spirals and the characteristics that can be achieved through their combinations make our modular metastructure suitable for various applications in robotics, aerospace, and medical engineering

Toxicity determination of three sturgeon species exposed to glyphosate

Glyphosate, N–(phosphonomethyl) glycine, has been widely used to control agricultural weeds in the north of Iran. However, it is also supposed to have adverse effects on natural sturgeon population. The present study was undertaken to evaluate the acute toxicity of glyphosate to three different sturgeon species (Huso huso, Acipenser stellatus, and A. persicus) under laboratory conditions. Fish were exposed to one of ten glyphosate concentrations (10 to 100 mg l–1 with 10 mg l–1 intervals), along with a control group. The values of the median lethal concentration (LC50) for each experimental species were estimated using a standard probit regression analyses after each 6, 12, 24, 48, 96, and 168 hours as exposure times. Results showed that increase in glyphosate exposure times up to 168 hours was simultaneous to decrease of the lethal concentration (LC50). 96–h LC50 of glyphosate for H. huso , A. stellatus and A . persicus were 26.4, 23.2 and 27.5 mg l–1, respectively. Glyphosate exhibited a slight to moderate toxicity in sturgeon species . However, it may negatively affect the natural population of sturgeons through decreasing of fry mass, smaller size of yolk sac and the initiation of unsafe behaviors