Bats are noted for having extremely powerful biosonar systems that enable them to move through and hunt through the thick foliage. They have a single emitter (mouth or nose) and two receivers in their biosonar system (ears). Some bat species, such as those belonging to the group's rhinophid and hipposiderid, feature intricate pinna motion patterns. These pinnae are divided into two groups: stiff movements and non-rigid motions. To understand how pinna sense worked has been studied in this thesis. The rigid pinna movements displayed a significantly different rotation, with revolutions axes spanning 180° in horizontal and curvature, according to axis-angle representations. The classification of landmarks on the pinna surface has explained two types of non-stiffed pinna movements. Additionally, a bio-inspired pinna has been used to explore the acoustic impact of the stiff pinna movements. All the given results showed precise accuracy in the motion of variance bats pinnae. The research initiative was initiated with a comprehensive exploration of various design concepts, primarily focused on elucidating the intricate interplay between actuator geometry and the resultant deformation of the pinna. Employing a structured design code facilitated the generation of an array of configurations, each subject to stringent conditions and parameter settings necessitating subsequent validation. After this design exploration, a tri-tiered hierarchy of forces, encompassing nominal, intermediate, and elevated magnitudes, was applied to instigate a systematic optimization process aimed at determining the most favorable deformation pattern. Computational simulations leveraging Finite Element Analysis (FEA) were conducted, accompanied by a rigorous material characterization procedure, to effectively quantify the extent of deformation across the array of configurations. A consequential phase of the investigation involved the implementation of Principal Component Analysis (PCA) to differentiate the inherent variability within the different deformation arrangements, shedding light on their relative structural and morphological distinctions. The culmination of the study encompassed the utilization of the Genetic Algorithm (GA), a sophisticated optimization technique, to facilitate the fine-tuning of deformation patterns in pursuit of the overarching goal: the deliberate induction of substantial and diverse variations in pinna morphology. In summary, the research trajectory progressed sequentially through design conceptualization, force-induced optimization, computational simulations incorporating FEA and material characterization, Variability analysis via PCA, and culminated in the deployment of the GA to achieve the prime objective of inducing pronounced variability in pinna configuration. The work was done as following, starting with design concepts, the main benefit of this is to understand how the geometry of actuator affects the pinna deformation. Using the design code to present several configurations that must have conditions and parameters to be validated. After that applying 3 different forces (zero, medium, and high) to get the optimization for pattern. Applying the FEA simulations with help of material characterization to display the displacement of the arrangements. Finally doing the Variability analysis by using the principal component analysis. Then concluding the work by using the Genetic algorithm for optimizations to reach the main goal which is large variability in the pinna shape. / Doctor of Philosophy / This research delves into the fascinating world of bats and their extraordinary biosonar systems, specifically focusing on the intricate mechanics of their pinnae—the external ear structures. Bats, known for their remarkable ability to navigate dense foliage using biosonar, have been a subject of keen scientific interest. The study explores the design and functionality of bat pinnae, with a special emphasis on understanding how different movements contribute to their biosonar capabilities. The investigation began with a comprehensive exploration of design concepts, aiming to unravel the complex relationship between actuator geometry and pinna deformation. A structured design code was employed to generate a range of configurations, each subjected to stringent conditions and parameters, requiring subsequent validation. Following this design exploration, a three-tiered hierarchy of forces—ranging from nominal to elevated magnitudes—was applied to initiate a systematic optimization process. Computational simulations, utilizing Finite Element Analysis (FEA) and rigorous material characterization, were conducted to quantify the extent of pinna deformation across various configurations. The study further implemented Principal Component Analysis (PCA) to discern inherent variability in different deformation patterns, shedding light on their structural and morphological distinctions. The research culminated in the deployment of the Genetic Algorithm (GA), a sophisticated optimization technique, to deliberately induce substantial and diverse variations in pinna morphology. In summary, the research trajectory progressed from design conceptualization to force-induced optimization, incorporating computational simulations and material characterization. Variability analysis through PCA provided insights into structural distinctions, and the use of the Genetic Algorithm aimed at achieving the overarching goal of inducing pronounced variability in pinna configuration. This work not only enhances our understanding of bat biosonar systems but also offers potential applications in bio-inspired design and acoustic engineering.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 138-140). Also available via the Internet.

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Orientador: Maria Del Pilar Taboada Sotomayor / Banca: Flavio Santos Damos / Banca: Arnaldo Cesar Pereira / Resumo: Eletrodos quimicamente modificados à base de pasta de carbono foram construídos para determinação de captopril, empregando catalisadores biomiméticos em potencial da enzima P450. O complexo que permitiu obter os resultados mais satisfatórios foi o bis(piridil)ftalocianinaferro (II) [Fe(dipy)Pc]. O sensor proposto foi avaliado em batelada e em sistema de análise por injeção em fluxo (FIA), e as condições de análise foram devidamente otimizadas empregando a amperometria. Em batelada obtiveram-se os melhores resultados aplicando potencial de 0,175 V vs Ag|AgCl(KClsat) e usando solução tampão TRIS 0,1 mol L-1 como eletrólito em pH 8,0. Nestas condições observou-se uma faixa linear de resposta para o sensor entre 25 e 165 μmol L-1; com uma sensibilidade de 2.315(±61) μA L mol-1 e um limite de detecção e quantificação de 0,9 e 3,1 μmol L-1, respectivamente. Em sistema em fluxo, os melhores resultados foram obtidos aplicando potencial de 0,100 V vs Ag|AgCl (KClsat) em solução carregadora de tampão TRIS 0,1 mol L-1 e pH 8.0, com volume de amostra injetado de 75 μL e vazão de 1,4 mL min-1. A faixa linear de resposta obtida no sistema em fluxo (FIA) foi entre 5,0 x 10-5 e 2,5 x 10-2 mol L-1, com uma sensibilidade de 210(±1) μA L mol-1 e uma reprodutibilidade menor que 4%, avaliado pelo valor do desvio padrão médio relativo (R.S.D.) para sete injeções consecutivas de solução padrão de captopril 2,5 x 10-3 mol L-1. A biomimeticidade do sensor foi estudada, assim como a seletividade e seus possíveis interferentes. O sensor biomimético foi aplicado na análise de formulações comerciais, amostras biológicas e ambientais (águas de rios e esgoto). Os resultados obtidos quando comparados com o método oficial de análise baseado na cromatografia líquida de alta eficiência (HPLC), mostraram boa eficiência do sensor desenvolvido na quantificação do captopril / Abstract: Chemically modified electrodes based on carbon paste were constructed for determination of captopril, catalysts employing biomimetic of the P450 enzyme. The compound that allowed to obtain the most satisfying results was the iron (II) phthalocyanine bis(pyridine) complex [Fe(dipy)Pc]. The proposed sensor was evaluated in batch system and flow injection analysis (FIA) and the analysis conditions were properly optimized employing amperometry. In batch experiments were obtaining the best results by applying a potential of 0,175 V vs Ag | AgCl (KClsat) and using 0.1 mol L-1 TRIS buffer at pH 8.0, the electrolyte. These conditions was observed under the linear response range for the sensor between 25 and 165 μmol L-1, with a sensitivity of 2315 (± 61) μA L mol-1 and quantification and detection limits of 0.9 and 3.1 μmol L-1, respectively . In the flow system the best results were obtained at the potential of 0,1 V vs. Ag | AgCl (KClsat) in carrier solution of 0.1 mol L-1 TRIS buffer at pH 8.0, with the injected sample volume of 75 mL and flow rate of 1.4 mL min-1. The linear response range obtained in the FIA system was between 5.0 x 10-5 and 2.5 x 10-2 mol L-1, with a sensitivity of 210 (± 1) μA L mol L-1 and the reproducibility value lower than 4 %, calculated the relative standard deviation (RSD) for seven consecutive injections of standard solution of captopril 2.5 x 10-3 mol L-1. The biomimetic characteristics of the sensor was studied and the selectivity and possible interfering. The biomimetic sensor has been applied to analysis of commercial formulations, biological and environmental samples (river water and sewage). The results compared with the official method of analysis based on high performance liquid chromatography (HPLC) showed the good efficiency of this sensor is developed quantification of captopril / Mestre

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This thesis presents biomimetic control of an anthropomorphic artificial finger actuated by three antagonistic shape memory alloy (SMA) muscle pairs that are each configured in a dual spring-biased configuration. This actuation system forms the basis for biomimetic tendon-driven flexion/extension of the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the artificial finger, as well as the abduction/adduction of its MCP joint. This work focuses on the design and experimental verification of a new fuzzy pulse-width-modulated proportional-integral-derivative (i.e. fuzzy PWM-PID) controller that is capable of realizing cocontraction of the SMA muscle pairs, as well as online tuning of the PID gains to deal with system nonlinearities and parameter uncertainties. One of the main purposes of this thesis is the proposed biomimetic cocontraction control strategy, which co-activates the antagonistic muscle pairs as a synergistic functional unit. It emulates a similar strategy in neural control, called “common drive,” employed by the central nervous system (CNS). In order to maintain a desired position of a joint, the corresponding agonistic muscle pairs are cocontracted by the CNS and numerical simulations using a dynamic model of the system. The performance advantage of the cocontracting fuzzy PWM-PID controller over the original PWM-PID controller is shown by experimental results. A successful application of the new controller to fingertip trajectory tracking tasks using the MCP joint’s flexion/extension and abduction/adduction is also described. Since commercially available SMA actuators used for artificial muscle pairs have limited stroke, a new compact design was considered to increase the stroke of SMA actuators with similar power capacity. The design and fabrication process of the new SMA actuators are described followed by preliminary testing of the actuators’ performance as artificial muscle pairs with the designed fuzzy PWM-PID control algorithm. / Graduate

Biomimetic synthesis is the branch of synthetic organic chemistry which attempts to learn from nature into order to solve the challenges of chemical synthesis. This thesis describes application of biomimetic principles to the total synthesis of three phenylethanoid alkaloid natural products: incargranine B; millingtonine and incargranine A. Chapter 1 provides a general introduction to the area. Specific introductions can be found at the start of each chapter. Chapter 1 introduces the concept of biomimicry and provides a brief overview of the development of the underlying concepts and terminology. The major biosynthetic pathways involved in the production of incargranine B, millingtonine and incargranine A (shikimic acid, ornithine alkaloids) are also introduced. Chapter 2 discusses the synthesis of incargranine B. Biosynthetic analysis of this dimeric alkaloid led us to question its structural assignment and suggest a structural revision. This speculative reassignment was validated through a biomimetic total synthesis of our proposed structure. Incargranine B was successfully prepared in a longest linear sequence of six steps, forming three new rings, four bonds and three contiguous stereocentres in a single biomimetic domino condensation/Mannich/SEAr sequence. Chapter 3 describes the synthesis of millingtonine. We proposed that millingtonine is biosynthetically related to incargranine B through a divergent/re-convergent network of pathways. Synthetic exploration of this hypothesis culminated in the total synthesis of millingtonine and discovery of an unanticipated biosynthetic intermediate, dia-millingtonine, which we propose as a previously unidentified natural product. . Chapter 4 details the synthesis of incargranine A. Incorporating dia-millingtonine into our biosynthetic hypothesis allowed the development of a four step bioimimetic total syntheses of incargranine A which was scaled-up to provide over one gram of natural product. Chapter 5 summarises the work presented and provides a perspective on its contribution to the field.

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The advancements made in technology over the past several decades have brought the field of humanoid robotics closer to integration into the everyday lives of humans. Despite these advances, the cost of these systems consistently remains high, thus limiting the environments in which these robots can be deployed. In this thesis, a pair of low-cost, bio-mimetic legs for a humanoid robot was developed with 12 degrees of freedom: three at the hip, one at the knee, and two at the ankle. Prior to developing the robot, a survey of the human-sized robotic legs released from 2006-2012 was conducted. The analysis included a summary of the key performance metrics and trends in series of human-sized robots. Recommendations were developed for future data reporting that will allow improved comparison of different prototypes. The design of the new robotic legs in this thesis utilized human anatomy data to devise performance parameters and select actuators. The developed system was able to achieve comparable ROM, size, weight, and torque to a six-foot tall human. Position and zero-moment point sensors were integrated for use in balancing, and a control architecture was developed. A model of the leg dynamics was created for designing balancing and walking algorithms. In addition, hydraulic actuators were evaluated for use in humanoid robotics, and testing was conducted in order to create a position control methodology. Finally, a predictive deadband controller was designed that was able to achieve accuracy of less than one degree using a valve with slow switching speed. / Master of Science