This chapter discusses properties and characteristics of ionic biopolymer-metal nanocomposites (IBMCs) as biomimetic multifunctional distributed nanoactuators, nanosensors, nanotransducers, and artificial muscles. After presenting some fundamental properties of biomimetic distributed nanosensing and nanoactuation of ionic polymer-metal composites (IPMCs) and IBMCs, the discussion extends to some recent advances in the manufacturing techniques and 3-D fabrication of IBMCs and some recent modeling and simulations, sensing and transduction, and product development. This chapter also presents procedures on how biopolymers such as chitosan and perfluorinated ionic polymers can be combined to make new nanocomposites with actuation, energy harvesting, and sensing capabilities. Chitin-based chitosan and ionic polymeric networks containing conjugated ions that can be redistributed by an imposed electric field and consequently act as distributed nanosensors, nanoactuators, and artificial muscles are also discussed. The manufacturing methodologies are briefly discussed, and the fundamental properties and characteristics of biopolymeric muscles as artificial muscles are presented. Two ionic models based on linear irreversible thermodynamics as well as charge dynamics of the underlying sensing and actuation mechanisms are also presented. Intercalation of biopolymers and ionic polymers and subsequent chemical plating of them with a noble metal by a reduction-oxidation (redox) operation is also reported and the properties of the new product are briefly discussed.

This chapter describes recent developments in the area of manmade microflyers. The design space for microflyers is described, along with fundamental physical limits to miniaturizing mechanisms, energy storage, and electronics. Aspects of aerodynamics at the scale of microflyers are discussed. Microflyer concepts developed by a number of researchers are described in detail. Because the focus is on bioinspiration and biomimetics, scaled-down versions of conventional aircraft, such as fixed-wing micro air vehicles and micro-helicopters, are not addressed. Modeling of the aeromechanics of flapping wing microflyers is described with an illustrative example. Finally, some of the sensing mechanisms used by natural flyers are discussed.

Even though current micro-nano fabrication technology has reached integration levels at which ultra-sensitive sensors can be fabricated, the sensing performance (bits per Joule) of synthetic systems are still orders of magnitude inferior to those observed in neurobiology. For example, the filiform hair in crickets operates at fundamental limits of noise and energy efficiency. Another example is the auditory sensor in the parasitoid fly Ormia ochracea that can precisely localize ultra-faint acoustic signatures in spite of the underlying physical limitations. Even though many of these biological marvels have served as inspirations for different types of neuromorphic sensors, the main focus of these designs has been to faithfully replicate the biological functions, without considering the constructive role of noise. In manmade sensors, device and sensor noise are typically considered nuisances, whereas in neurobiology noise has been shown to be a computational aid that enables sensing and operation at fundamental limits of energy efficiency and performance. In this chapter, we describe some of the important noise exploitation and adaptation principles observed in neurobiology and how they can be systematically used for designing neuromorphic sensors. Our focus is on two types of noise exploitation principles, namely, (a) stochastic resonance and (b) noise shaping, which are unified within a framework called ΣΔ learning. As a case study, we describe the application of ΣΔ learning for the design of a miniature acoustic source localizer, the performance of which matches that of its biological counterpart (O. ochracea).

Engineered Biomimicry covers a broad range of research topics in the emerging discipline of biomimicry. Biologically inspired science and technology, using the principles of math and physics, has led to the development of products as ubiquitous as VelcroTM (modeled after the spiny hooks on plant seeds and fruits). Readers will learn to take ideas and concepts like this from nature, implement them in research, and understand and explain diverse phenomena and their related functions. From bioinspired computing and medical products to biomimetic applications like artificial muscles, MEMS, textiles and vision sensors, Engineered Biomimicry explores a wide range of technologies informed by living natural systems. Engineered Biomimicry helps physicists, engineers and material scientists seek solutions in nature to the most pressing technical problems of our times, while providing a solid understanding of the important role of biophysics. Some physical applications include adhesion superhydrophobicity and self-cleaning, structural coloration, photonic devices, biomaterials and composite materials, sensor systems, robotics and locomotion, and ultra-lightweight structures. - Explores biomimicry, a fast-growing, cross-disciplinary field in which researchers study biological activities in nature to make critical advancements in science and engineering - Introduces bioinspiration, biomimetics, and bioreplication, and provides biological background and practical applications for each - Cutting-edge topics include bio-inspired robotics, microflyers, surface modification and more

Structural colors originate in the scattering of light from ordered microstructures, thin films, and even irregular arrays of electrically small particles, but they are not produced by pigments. Examples include the flashing sparks of colors in opals and the brilliant hues of some butterflies such as Morpho rhetenor. Structural colors can be implemented industrially to produce structurally colored paints, fabrics, cosmetics, and sensors.

Materials such as bone, teeth, and seashells possess remarkable combinations of properties despite the poor structural quality of their ingredients (brittle minerals and soft proteins). Nacre from mollusk shells is 3,000 times tougher than the brittle mineral it is made of, a level of toughness amplification currently unmatched by any engineering material. For this reason, nacre has become the model for bio-inspiration for novel structural materials. The structure of nacre is organized over several length scales, but the microscopic brick-and-mortar arrangement of the mineral tablets is prominent. This staggered structure provides a universal approach to arranging hard building blocks in nature and is also found in bone and teeth. Recent models have demonstrated how an attractive combination of stiffness, strength, and toughness can be achieved through the staggered structure. The fabrication of engineering materials that duplicate the structure, mechanics, and properties of natural nacre still present formidable challenges to this day.

In a sense, the archetype of bioinspiration for materials design and use is textiles. The field of biomimesis has spawned many new materials and continues to be a fruitful field of investigation. This chapter presents the current state of bioinspiration in textiles, how this has resulted in improved fibrous materials, how it may inform our continued progress. Because I have found many preconceived notions about the field that need addressing before the application of biomimetics to textiles can be truly appreciated, I begin with an introduction to textiles. Next, naturally enough, the discipline of biomimesis is introduced and then fleshed out in terms of its textile engineering importance. Following this, some details on fiber and textile science and engineering are discussed and biological concepts germane to our topic are presented. In the last step in this journey, the marriage of biomimesis and textiles is performed and some consequences revealed. Finally, I offer some prognostications on the topic.

Insects are dependent on the spatial, spectral, and temporal distributions of light in the environment for flight control and navigation. This chapter reports on flight trials of implementations of insect-inspired behaviors on unmanned aerial vehicles. Optical-flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigational capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other demonstrated vision-based techniques include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low-cost inertial heading and attitude systems.

Self-organization and self-healing appeal to humans because difficult and repeated actions can be avoided through automation via bottom-up nonhierarchical processes. This is in contrast to the top-level controlled manner we normally apply as an action strategy in manufacturing and maintenance work. This chapter presents eight different self-organizing and self-healing approaches in nature and takes a look at realized and potential applications. Furthermore, the core principles for each approach are described using simplified drawings in order to make the ideas behind the self-organizing and self-healing principles more accessible to design practitioners.

The fabrication of three-dimensional (3D) scaffold architectures that closely approximate or effectively mimic native tissue extracellular matrix (ECM) is essential for regenerative success. In tissue engineering, native differentiable cells are incorporated into 3D scaffolds along with growth factors and other proteins. Materials used for the 3D scaffold construction must be biocompatible and bioresorbable to minimize adverse reactions during tissue regeneration. A 3D architecture is created by utilizing materials with specific surface properties, porosity, mechanical strength, etc., to improve desired cell activity and enhance tissue growth. Ideal 3D scaffolds should also not only have hierarchical macroporous structures comparable to those of living tissue, but they should also have surface features on the nanometer scale to improve cell adhesion and accelerate cell in growth.