Prokaryotic flagellum is considered as the only known example of a biological "wheel," a system capable of converting the action of rotatory actuator into a continuous propulsive force. For this reason, flagella are an interesting case study in soft robotics and they represent an appealing source of inspiration for the design of underwater robots. A great number of flagellum-inspired devices exists, but these are all characterized by a size ranging in the micrometer scale and mostly realized with rigid materials. Here, we present the design and development of a novel generation of macroscale underwater propellers that draw their inspiration from flagellated organisms. Through a simple rotatory actuation and exploiting the capability of the soft material to store energy when interacting with the surrounding fluid, the propellers attain different helical shapes that generate a propulsive thrust. A theoretical model is presented, accurately describing and predicting the kinematic and the propulsive capabilities of the proposed solution. Different experimental trials are presented to validate the accuracy of the model and to investigate the performance of the proposed design. Finally, an underwater robot prototype propelled by four flagellar modules is presented.

In this study, the structures and mechanical properties of the silver-titanium dioxide nanocomposite material were investigated using Atomic Force Microscopy (AFM). These properties include surface roughness, hardness, and reduced Young's modulus. The nanocomposite material was successfully synthesized using the Horizontal Vapor Phase Growth (HVPG) technique which yielded shapes such as nanoparticles, nanospheres, nanorods, triangular nanocomposites, and nanocrystals. Characterization of nanocomposite materials was done through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy to elucidate material shape, diameter, and composition. The pour plate technique combined with McFarland standards was used to evaluate the antibacterial activity of the nanocomposite material against Staphylococcus aureus . The nanocomposite material was able to eradicate bacteria and was suitable for coating applications effectively.

Flagellated micro-organism are regarded as excellent swimmers within their size scales. This, along with the simplicity of their actuation and the richness of their dynamics makes them a valuable source of inspiration to desing continuum, self-propelled underwater robots. Here we introduce a soft, flagellum-inspired system which exploits the compliance of its own body to passively attain a range of geometrical configurations from the interaction with the surrounding fluid. The spontaneous formation of stable helical waves along the length of the flagellum is responsible for the generation of positive net thrust. We investigate the relationship between actuation frequency and material elasticty in determining the steady-state configuration of the system and its thrust output. This is ultimately used to perform a parameter identification procedure of an elastodynamic model aimed at investigating the scaling laws in the propulsion of flagellated robots.

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This paper concerns with the design of a three degrees of freedom robotic arm, which is intended to pick and place lightweight objects based on a color sorting mechanism. It is mainly made of three joints, a gripper, two rectangular shaped links, a rotary table and a rectangular platform. The angular rotation of each joint is powered by a servomotor. Furthermore, the angular position of each servomotor shaft is controlled by a signal from an Arduino microcontroller which executes a Matlab code. The Matlab code includes the inverse kinematics equations which are necessary for the determination of the target joint angles for a certain Cartesian position of the end-effector. The robotic arm's design process included several static and dynamic calculations, mechanical properties calculations and prototype testing in order to provide a final product with well-established structure and functionalities.

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