Maneuverable and Efficient Locomotion of a Myriapod Robot with Variable Body-Axis Flexibility via Instability and Bifurcation

Aoi Shinya, Yabuuchi Yuki, Morozumi Daiki, et al. Maneuverable and Efficient Locomotion of a Myriapod Robot with Variable Body-Axis Flexibility via Instability and Bifurcation. Soft Robotics 6, NT64 (2023); https://doi.org/10.1089/soro.2022.0177

Design and Locomotion Studies of a Miniature Centipede-Inspired Robot

Many applications, such as search and rescue missions, hazardous environment exploration, and surveillance, call for miniature robots capable of agile locomotion in a variety of unpredictable environments. Recent advances in meso-scale fabrication techniques and an understanding of biological insect locomotion have enabled the creation of multiple miniature legged robots to meet this demand. Nearly all insect-scale legged robots take inspiration from rigid-body hexapods; however, another unique body morphology found in nature is that of the centipede, characterized by its many legs and flexible body. These characteristics are expected to offer performance benefits in terms of agility, stability, robustness, and adaptability.Engineering and Applied Science

Silicon and Polymer Components for Microrobots

This dissertation presents the characterization and implementation of the first microfabrication process to incorporate high aspect ratio compliant polymer structures in-plane with traditional silicon microelectromechanical systems (MEMS). This discussion begins with in situ mechanical characterization of microscale polymer springs using silicon-on-insulator-MEMS (SOI-MEMS). The analysis compares microscale samples that were tested on-chip with macroscale samples tested using a dynamic mechanical analyzer. The results describe the effect of the processing steps on the polymer during fabrication and help to guide the design of mechanisms using polymers. Characterization of the dielectric breakdown of polymer thin films with thicknesses from 2 to 14 μm between silicon electrodes was also performed. The results demonstrate that there is a strong dependence of the breakdown field on both the electrode gap and shape. The breakdown fields ranged from 250 V/μm to 635 V/μm, depending on the electrode geometry and gap, approaching 10x the breakdown fields for air gaps of the same size. These materials were then used to create compliant all-polymer thermal and electrostatic microactuators. All-polymer thermal actuators demonstrated displacements as large at 100 μm and forces as high as 55 μN. A 1 mm long electrostatic dielectric elastomer actuator demonstrated a tip displacement as high as 350 μm at 1.1 kV with a electrical power consumption of 11μW. The actuators are fabricated with elastomeric materials, so they are very robust and can undergo large strains in both tension and bending and still operate once released. Finally, the compliant polymer and silicon actuators were combined in an actuated bio-inspired system. Small insects and other animals use a multitude of materials to realize specific functions, including locomotion. By incorporating compliant elastomer structures in-plane with traditional silicon actuators, compact energy storage systems based on elastomer springs for small jumping robots were demonstrated. Results include a 4 mm x 4 mm jumping mechanism that has reached heights of 32 cm, 80x its own height, and an on-chip actuated mechanism that has been used to propel a 1.4mg projectile over 7 cm

Methods for Building Self-Folding Machines

Origami can turn a sheet of paper into complex three-dimensional shapes, and similar folding techniques can be used to build structures and mechanisms. However, folding by hand can be difficult and time consuming. This has led to the development of self-folding materials that transform themselves from flat sheets into 3D shapes by bending themselves along hinges. A variety of self-folding methods have been demonstrated at a variety of length scales, but they have not yet been used to build complex machines. This dissertation demonstrates that self-folding can produce functional machines with a new laminate we refer to as a shape memory composite. We characterize the behavior of this composite with models and experimental data, and use this information to develop design rules for self-folding. We apply these rules to create devices at multiple length scales, including a model crane, a crawling robot, a lamp, and a model ship.Engineering and Applied Sciences - Engineering Science

Dynamik und Kinematik der Lokomotion von Formica polyctena

In der vorliegenden Dissertation wurde untersucht, welche kinematischen und dynamischen Muster sich bei der Ameisenlokomotion identifizieren lassen und wie sich diese im Vergleich zu größeren Arten darstellen. Es wurde gezeigt, dass Waldameisen bei ebener Lokomotion dieselbe Gangdynamik über einen weiten Geschwindigkeitsbereich benutzten, ohne das alternierende, tripodale Schrittmuster aufzulösen. Mit wachsenden Laufgeschwindigkeiten erhöhte sich Schrittlänge und Schrittfrequenz. Die Energetik des Körperschwerpunkts indizierte einen federnden Gang, da kinetische und potentielle Energie nahezu in Phase verliefen. In den Vorderbeinen wurde eine hohe Maß an Nachgiebigkeit festgestellt, welche zu geringen vertikalen Oszillationen des Körperschwerpunktes führt und die Aufrechterhaltung des Bodenkontaktes auch bei höheren Geschwindigkeiten ermöglicht. Federnde Gangarten, ohne Flugphasen, scheinen eine weit verbreitete Strategie bei kleinen, schnell laufenden Lebewesen zu sein und können hinlänglich gut über das bipedale Masse-Feder-Modell beschrieben werden. Diese Form der Lokomotion wird auch als „Grounded Running“ bezeichnet und scheint, gemäß unseren Ergebnissen, auch für Ameisen die bevorzugte Fortbewegungsstrategie in der Ebene zu sein. Grundvoraussetzung für das Gelingen des Projektes war die Entwicklung eines miniaturisierten Messplatzes zur Erfassung der dreidimensionalen Bodenreaktionskräfte der Einzelbeine kleiner Insekten, bei gleichzeitiger Aufzeichnung der Kinematik. Im Rahmen dieser Arbeit ist es gelungen eine neuartige Ultraminiaturkraftmessplattform mit einem Auflösungsvermögen im Mikronewton-Bereich zu entwickeln und gemeinsam mit einer Hochgeschwindigkeits-Videokamera in einen weltweit einzigartigen Messplatz zu integrieren