Julian F. V. Vincent

Rolling in Nature and Robotics： A Review

This paper presents a review of recent rolling robots including Rollo from Helsinki University of Technology, Spherical Mobile Robot from the Politecnico of Bari, Sphericle from the University of Pisa, Spherobot from Michigan State University, August from Azad University of Qazvin and the University of Tehran, Deformable Robot from Ritsumeijan University, Kickbot from the Massachusetts Institute of Technology, Gravitational Wheeled Robot from Kinki University, Gyrover from Carnegie Mellon University, Roball from the Université de Sherbrooke, and Rotundus from the Ångström Space Technology Center.Seven rolling robot design principles are presented and discussed (Sprung central member, Car driven, Mobile masses, Hemispherical wheels, Gyroscopic stabilisation, Ballast mass — fixed axis, and Ballast mass — moving axis). Robots based on each of the design principles are shown and the performances of the robots are tabulated. An attempt is made to grade the design principles based on their suitability for movement over an unknown and varied but relatively smooth terrain. The result of this comparison suggests that a rolling robot based on a mobile masses principle would be best suited to this specific application.Some wonderful rolling organisms are introduced and defined as “active” or “passive” depending on whether they generate their own rolling motion or external forces cause their rolling.

Planetary Micro-Penetrator Concept Study with Biomimetric Drill and Sampler Design

Due to ultraviolet flux to the surface layers of most solar system bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration, drilling and sampling to detect chemical signature of extant or extinct life. To seek a compact solution to this issue, we present a micro-penetrator concept (mass < 10 kg) that is suited for planetary deployment and in situ investigation of chemical and physical properties. To draw inspiration from nature, a biomimetic drill and sampler subsystem is designed as a penetrator instrument based on the working mechanism of a wood wasp ovipositor to sample beneath the sterile layer for biomarker detection. One of the major limitations of sampling in relatively low gravity environments (such as asteroids, Mars, etc) is the need for high axial force when using conventional drills. The ovipositor drill is proposed to address this limitation by applying a novel concept of reciprocating motion that requires no external force. It is lightweight (0.5 kg), driven at low power (3 W), and able to drill deep (1-2 m). Tests have shown that a reciprocating drill is feasible and has the potential of improving drill efficiency without receiving any external force. As part of the European space agency (ESA) project on bionics and space system design [1], this study provides a conceptual design of the micro-penetrator targeted for a near earth asteroid mission. With bionics-enabling technology, the overall penetration/drilling/sampling system provides a small, light and energy efficient solution to in situ astrobiological studies, which is crucial for space exploration. Such a micro-penetrator can be used for exploration of terrestrial-type planets or other small bodies of the solar system with a moderate level of modifications.

Biomimetics of Campaniform Sensilla: Measuring Strain from the Deformation of Holes

We present a bio-inspired strategy for designing embedded strain sensors in space structures. In insects, the campaniform sensillum is a hole extending through the cuticle arranged such that its shape changes in response to loads. The shape change is rotated through 90° by the suspension of a bell-shaped cap whose deflection is detected by a cell beneath the cuticle. It can be sensitive to displacements of the order of 1 nm. The essential morphology, a hole formed in a plate of fibrous composite material, was modelled by Skordos et al. who showed that global deformation of the plate (which can be flat, curved or a tube) induces higher local deformation of the hole due to its locally higher compliance. Further developments reported here show that this approach can be applied to groups of holes relative to their orientation.The morphology of the sensillum in insects suggests that greater sensitivity can be achieved by arranging several holes in a regular pattern; that if the hole is oval it can be “aimed” to sense specific strain directions; and that either by controlling the shape of the hole or its relationship with other holes it can have a tuned response to dynamic strains.We investigate space applications in which novel bio-inspired strain sensors could successfully be used.

The Materials Revolution

In the final essay of this series the gaps between biology and engineering are examined, and methods are suggested for crossing them. Creativity is seen as the essential, and TRIZ (the Russian Theory of Inventive Problem Solving) is recommended as the best set of methods both for stimulating creativity and for solving technical problems. When the catalogue of Inventive Principles of TRIZ is used to bring biology and technology to the same level of detail, the comparison shows that the similarity is only about 12%. The differences largely reside in the reliance of energy as a controlling parameter in conventional technology and the replacement of energy by information in biological systems. Although we might be moving slowly in this direction, a numerically based comparison such as this should provide more impetus.

Hydration and tanning in insect cuticle

Abstract The water content of larval and puparial cuticle of Calliphora vomitoria has been measured under differing conditions using nuclear magnetic resonance, differential scanning calorimetry and simple gravimetry. On average, 2.5 molecules of water are associated with each amino acid side chain. This water is not displaced by tanning, even though tanning reduces the overall content of freezable water, suggesting that tanning agents do not interact with polar groups on the protein but increase overall hydrophobicity. This refutes normally accepted concepts of tanning by covalent cross linking. Additionally, covalent cross linking cannot account for the reduction in swellability of the cuticle on tanning.

Bio-inspired drill for planetary subsurface sampling: Literature survey, conceptual design and feasibility study

It is widely acknowledged that the next significant challenge in planetary exploration is to be able to drill deeply (two meters seems the most scientifically valuable and the most technologically reasonable) into the surface of solar system bodies for chemical or physical data. Major limitation of using conventional rotary drills in low gravity environments (such as Mars, asteroids, comet, etc) is the need for high axial force, which suffers from big overhead mass, buckling problem, and power hungriness. Though drills using percussive motion may operate in low mass and power, the drilling rate is generally slow. Drawing inspiration from nature for a lightweight and energy efficient solution, we propose a novel drilling method based on the working mechanism of wood wasp ovipositors. The bio-inspired drill requires no reactive external force by applying two-valve-reciprocating motion. The proposed bio-inspired system indicates enhanced utility that is critical for space missions where premium is placed on mass, volume and power. Biological systems are similarly constrained making biomimetic technology uniquely suited and advantageous as a model of miniaturized systems. As a result of the European Space Agency (ESA) project on bionics and space system design [Ellery, 2005], this paper presents a conceptual design of the bio-inspired drill. Lab-based experiments have shown that the two-valve-reciprocating drilling method is feasible and has potential of improving drill efficiency without any additional overhead force or mass.

If it's Tanned it Must be Dry: A Critique

The mechanism of phenolic tanning of insect cuticle, and other extracellular protein structures such as byssus and perisarc, has been supposed to be due to specific covalent cross links. Yet cuticle can be swollen in a strong H-bond breaker, an observation that instantly and irrevocably disproves this theory. Physico-chemical expulsion of water is a much more robust mechanism which accords more closely with experimental observation, and suggests stabilisation mechanisms which would give advantages for technical composite materials.

An Ontology of Biomimetics

Statistical analysis of the mechanisms and processes in biological organisms (derived from published, peer-reviewed, research papers) reveals that there are ‘design’ rules which could be used to facilitate technical design, thus producing biologically inspired design without the necessity for the designer using such a system to invoke biology or biological expertise since this has already been done when the rules were extracted. Even so, this is not a necessary and sufficient condition for good design. Four principles derived from the Russian system TRIZ (widely used in technology as an objective system for solving problems inventively) are highlighted and summarised as Local Quality; Consolidation or Merging; Dynamics; Prior Cushioning. More design rules, derived in the same way, are needed to expand the importance of information (sensu lato) and materials, two aspects that the TRIZ system currently does not deal with adequately.

Advantages of a Biomimetic Stiffness Profile in Pitching Flexible Fin Propulsion

The use of oscillating flexible fins in propulsion has been the subject of several studies in recent years, but attention is rarely paid to the specific role of stiffness profile in thrust production. Stiffness profile is defined as the variation in local chordwise bending stiffness (EI) of a fin, from leading to trailing edge. In this study, flexible fins with a standard NACA0012 shape were tested alongside fins with a stiffness profile mimicking that of a Pumpkinseed Sunfish (Lepomis gibbosus). The fins were oscillated with a pitching sinusoidal motion over a range of frequencies and amplitudes, while torque, lateral force and static thrust were measured.Over the range of oscillation parameters tested, it was shown that the fin with a biomimetic stiffness profile offered a significant improvement in static thrust, compared to a fin of similar dimensions with a standard NACA0012 aerofoil profile. The biomimetic fin also produced thrust more consistently over each oscillation cycle.A comparison of fin materials of different stiffness showed that the improvement was due to the stiffness profile itself, and was not simply an effect of altering the overall stiffness of the fin. Fins of the same stiffness profile were observed to follow the same thrust-power curve, independent of the stiffness of the moulding material. Biomimetic fins were shown to produce up to 26% greater thrust per watt of input power, within the experimental range.

Applications — Influence of Biology on Engineering

Examples are presented showing the way in which biological systems produce a range of functions which can be implemented in engineering, such as feedback-control of stiffness (muscles and nervous system), the design of fault-free structures (trees) and damage-tolerant materials (wood) and high performance insulation (penguin feathers) and shock absorbers (hedgehog spines).