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Description
Multi-material manufacturing combines multiple fabrication processes to produce individual parts that can be made up of several different materials. These processes can include both additive and subtractive manufacturing methods as well as embedding other components during manufacturing. This yields opportunities for creating single parts that can take the

Multi-material manufacturing combines multiple fabrication processes to produce individual parts that can be made up of several different materials. These processes can include both additive and subtractive manufacturing methods as well as embedding other components during manufacturing. This yields opportunities for creating single parts that can take the place of an assembly of parts produced using conventional techniques. Some example applications of multi-material manufacturing include parts that are produced using one process then machined to tolerance using another, parts with integrated flexible joints, or parts that contain discrete embedded components such as reinforcing materials or electronics.

Multi-material manufacturing has applications in robotics because, with it, mechanisms can be built into a design without adding additional moving parts. This allows for robot designs that are both robust and low cost, making it a particularly attractive method for education or research. 3D printing is of particular interest in this area because it is low cost, readily available, and capable of easily producing complicated part geometries. Some machines are also capable of depositing multiple materials during a single process. However, up to this point, planning the steps to create a part using multi-material manufacturing has been done manually, requiring specialized knowledge of the tools used. The difficulty of this planning procedure can prevent many students and researchers from using multi-material manufacturing.

This project studied methods of automating the planning of multi-material manufacturing processes through the development of a computational framework for processing 3D models and automatically generating viable manufacturing sequences. This framework includes solid operations and algorithms which assist the designer in computing manufacturing steps for multi-material models. This research is informing the development of a software planning tool which will simplify the planning needed by multi-material fabrication, making it more accessible for use in education or research.

In our paper, Voxel-Based Cad Framework for Planning Functionally Graded and Multi-Step Rapid Fabrication Processes, we present a new framework for representing and computing functionally-graded materials for use in rapid prototyping applications. We introduce the material description itself, low-level operations which can be used to combine one or more geometries together, and algorithms which assist the designer in computing manufacturing-compatible sequences. We then apply these techniques to several example scenarios. First, we demonstrate the use of a Gaussian blur to add graded material transitions to a model which can then be produced using a multi-material 3D printing process. Our second example highlights our solution to the problem of inserting a discrete, off-the-shelf part into a 3D printed model during the printing sequence. Finally, we implement this second example and manufacture two example components.
ContributorsBrauer, Cole D (Author) / Aukes, Daniel (Thesis director) / Sodemann, Angela (Committee member) / Engineering Programs (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
Classical planning is a field of Artificial Intelligence concerned with allowing autonomous agents to make reasonable decisions in complex environments. This work investigates
the application of deep learning and planning techniques, with the aim of constructing generalized plans capable of solving multiple problem instances. We construct a Deep Neural Network that,

Classical planning is a field of Artificial Intelligence concerned with allowing autonomous agents to make reasonable decisions in complex environments. This work investigates
the application of deep learning and planning techniques, with the aim of constructing generalized plans capable of solving multiple problem instances. We construct a Deep Neural Network that, given an abstract problem state, predicts both (i) the best action to be taken from that state and (ii) the generalized “role” of the object being manipulated. The neural network was tested on two classical planning domains: the blocks world domain and the logistic domain. Results indicate that neural networks are capable of making such
predictions with high accuracy, indicating a promising new framework for approaching generalized planning problems.
ContributorsNakhleh, Julia Blair (Author) / Srivastava, Siddharth (Thesis director) / Fainekos, Georgios (Committee member) / Computer Science and Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Soft robots currently rely on additional hardware such as pumps, high voltage supplies,light generation sources, and magnetic field generators for their operation. These components resist miniaturization; thus, embedding them into small-scale soft robots is challenging. This issue limits their applications, especially in hyper-redundant mobile robots. This dissertation aims at addressing some of the

Soft robots currently rely on additional hardware such as pumps, high voltage supplies,light generation sources, and magnetic field generators for their operation. These components resist miniaturization; thus, embedding them into small-scale soft robots is challenging. This issue limits their applications, especially in hyper-redundant mobile robots. This dissertation aims at addressing some of the challenges associated with creating miniature, untethered soft robots that can function without any attachment to external power supplies or receiving any control signals from outside sources. This goal is accomplished by introducing a soft active material and a manufacturing method that together, facilitate the miniaturization of soft robots and effectively supports their autonomous, mobile operation without any connection to outside equipment or human intervention. The soft active material presented here is a hydrogel based on a polymer called poly(Nisopropylacrylamide) (PNIPAAm). This hydrogel responds to changes in the temperature and responds by expanding or contracting. A major challenge regarding PNIPAAm-based hydrogels is their slow response. This challenge is addressed by introducing a mixedsolvent photo-polymerization technique that alters the pore structure of the hydrogel and facilitates the water transport and thus the rate of volume change. Using this technique, the re-swelling response time of hydrogels is reduced to 2:4min – over 25 times faster than hydrogels demonstrated previously. The material properties of hydrogels including their response rate and Young’s modulus are tuned simultaneously. The one-step photopolymerization using UV light is performed in under 15 sec, which is a significant improvement over thermo-polymerization, which takes anywhere between a few minutes to several hours. Photopolymerization is key towards simplifying recipes, improving access to these techniques, and making them tractable for iterative design processes. To address the manufacturing challenges, soft voxel actuators (SVAs) are presented. SVAs are actuated by electrical currents through Joule heating. SVAs weighing only 100 mg require small footprint microcontrollers for their operation which can be embedded in the robotic system. The advantages of hydrogel-based SVAs are demonstrated through different robotic platforms namely a hyper-redundant manipulator with 16 SVAs, an untethered miniature robot for mobile underwater applications using 8 SVAs, and a gripper using 32 SVAs.
ContributorsKhodambashi, Roozbeh (Author) / Aukes, Daniel (Thesis advisor) / Sugar, Thomas (Committee member) / Nam, Changho (Committee member) / Arizona State University (Publisher)
Created2021
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Description
In nature, some animals have an exoskeleton that provides protection, strength, and stability to the organism, but in engineering, an exoskeleton refers to a device that augments or aids human ability. However, the method of controlling these devices has been a challenge historically. Depending on the objective, control systems for

In nature, some animals have an exoskeleton that provides protection, strength, and stability to the organism, but in engineering, an exoskeleton refers to a device that augments or aids human ability. However, the method of controlling these devices has been a challenge historically. Depending on the objective, control systems for exoskeletons have ranged from devices as simple spring-loaded systems to using sensors such as electromyography (EMG). Despite EMGs being very common, force sensing resistors (FSRs) can be used instead. There are multiple types of exoskeletons that target different areas of the human body, and the targeted area depends on the need of the device. Usually, the devices are developed for either medical or military usage; for this project, the focus is on medical development of an automated elbow joint to assist in rehabilitation. This thesis is a continuation of my ASU Barrett honors thesis, Upper-Extremity Exoskeleton. While working on my honors thesis, I helped develop a design for an upper extremity exoskeleton based on the Wilmer orthosis design for Mayo Clinic. Building upon the design of an orthosis, for the master’s thesis, I developed an FSR control system that is designed using a Wheatstone bridge circuit that can provide a clean reliable signal as compared to the current EMG setup.
ContributorsCarlton, Bryan (Author) / Sugar, Thomas (Thesis advisor) / Aukes, Daniel (Committee member) / Hollander, Kevin (Committee member) / Arizona State University (Publisher)
Created2023
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Description
This dissertation introduces and examines Soft Curved Reconfigurable Anisotropic Mechanisms (SCRAMs) as a solution to address actuation, manufacturing, and modeling challenges in the field of soft robotics, with the aim of facilitating the broader implementation of soft robots in various industries. SCRAM systems utilize the curved geometry of thin elastic

This dissertation introduces and examines Soft Curved Reconfigurable Anisotropic Mechanisms (SCRAMs) as a solution to address actuation, manufacturing, and modeling challenges in the field of soft robotics, with the aim of facilitating the broader implementation of soft robots in various industries. SCRAM systems utilize the curved geometry of thin elastic structures to tackle these challenges in soft robots. SCRAM devices can modify their dynamic behavior by incorporating reconfigurable anisotropic stiffness, thereby enabling tailored locomotion patterns for specific tasks. This approach simplifies the actuation of robots, resulting in lighter, more flexible, cost-effective, and safer soft robotic systems. This dissertation demonstrates the potential of SCRAM devices through several case studies. These studies investigate virtual joints and shape change propagation in tubes, as well as anisotropic dynamic behavior in vibrational soft twisted beams, effectively demonstrating interesting locomotion patterns that are achievable using simple actuation mechanisms. The dissertation also addresses modeling and simulation challenges by introducing a reduced-order modeling approach. This approach enables fast and accurate simulations of soft robots and is compatible with existing rigid body simulators. Additionally, this dissertation investigates the prototyping processes of SCRAM devices and offers a comprehensive framework for the development of these devices. Overall, this dissertation demonstrates the potential of SCRAM devices to overcome actuation, modeling, and manufacturing challenges in soft robotics. The innovative concepts and approaches presented have implications for various industries that require cost-effective, adaptable, and safe robotic systems. SCRAM devices pave the way for the widespread application of soft robots in diverse domains.
ContributorsJiang, Yuhao (Author) / Aukes, Daniel (Thesis advisor) / Berman, Spring (Committee member) / Lee, Hyunglae (Committee member) / Marvi, Hamidreza (Committee member) / Srivastava, Siddharth (Committee member) / Arizona State University (Publisher)
Created2023
Description
Undulatory locomotion is a unique form of swimming that generates thrust through the propagation of a wave through a fish’s body. The proposed device utilizes a constrained compliant material with a single actuator to generate an undulatory motion. This paper draws inspiration from Anguilliformes and discusses the kinematics and dynamics

Undulatory locomotion is a unique form of swimming that generates thrust through the propagation of a wave through a fish’s body. The proposed device utilizes a constrained compliant material with a single actuator to generate an undulatory motion. This paper draws inspiration from Anguilliformes and discusses the kinematics and dynamics of wave propagation of an underwater robot. A variety of parameters are explored through modeling and are optimized for thrust generation to better understand the device. This paper validates the theoretical spine behavior through experimentation and provides a path forward for future development in device optimization for various applications. Previous work developed devices that utilized either paired soft actuators or multiple redundant classical actuators that resulted in a complex prototype with intricate controls. The work of this paper contrasts with prior work in that it aims to achieve undulatory motion through passive actuation from a single actively driven point which simplifies the control. Through this work, the goal is to further explore low-cost soft robotics via bistable mechanisms, continuum material properties, and simplified modeling practices.
ContributorsKwan, Anson (Author) / Aukes, Daniel (Thesis advisor) / Zhang, Wenlong (Committee member) / Marvi, Hamid (Committee member) / Arizona State University (Publisher)
Created2023
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Description
Unmanned aerial vehicles (UAVs) have revolutionized various fields, but their use in dynamic environments is still limited due to safety concerns arising from sensor malfunctions and localization errors. Inspired by birds, which exhibit unparalleled maneuverability and adaptability to dynamic environments by synergizing mechanical compliance with control, this research focused on

Unmanned aerial vehicles (UAVs) have revolutionized various fields, but their use in dynamic environments is still limited due to safety concerns arising from sensor malfunctions and localization errors. Inspired by birds, which exhibit unparalleled maneuverability and adaptability to dynamic environments by synergizing mechanical compliance with control, this research focused on developing a new generation of bio-inspired soft/compliant UAVs with mechanical intelligence that can withstand collisions and enable aerial interaction. The proposed approach is to harness collision energies and switch into the next favorable configuration, which helps retain stability and successfully fly even in the presence of external forces. It investigated various types of active/passive reconfigurable UAVs to demonstrate this idea. The first approach looked into designs of compliant reconfigurable quadrotors by employing springs which can reduce their dimension under external forces, thereby sustaining 2D planar collision forces and enabling flights through narrow gaps in a squeeze-and-fly manner. Next, fabric-based soft UAVs made of pneumatic beams were successfully explored to design lightweight and collision-resilient quadrotors to demonstrate 3D collision-resilience and impact-based perching. This research contributes to thorough modeling of the unique dynamics of these reconfigurable quadrotors and proposes various adaptive and learning-based controllers for robust low-level tracking. Finally, these controllers were integrated into a novel collision-inclusive motion planning framework based-on optimal control theory to perform physical interaction tasks, such as contact-based navigation, mapping, and inspection. In essence, this research redefines safety for UAVs and expands their capabilities for contact-rich tasks.
ContributorsPatnaik, Karishma (Author) / Zhang, Wennlong (Thesis advisor) / Tsakalis, Konstantinos (Committee member) / Aukes, Daniel (Committee member) / Arizona State University (Publisher)
Created2023
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Description
Foldable robots have gained popularity in recent years due to their versatility and portability. However, the use of composite hinges in these systems has posed challenges in terms of manufacturing complexity and cost. Historically, single material robots were very limited due to the fact that both the link and the

Foldable robots have gained popularity in recent years due to their versatility and portability. However, the use of composite hinges in these systems has posed challenges in terms of manufacturing complexity and cost. Historically, single material robots were very limited due to the fact that both the link and the hinge are made with the same material and striking a balance with stiffness of the link and flexibility of the hinge has been very difficult. Hinges would undergo fatigue within hundreds of cycles and show non-linear wear and physical properties. This research proposes an innovative approach to simplify foldable robotics by replacing composite hinges with single material flexure hinges. The proposed hinges are manufactured using a CO2 laser cutter and are designed to enhance performance and reduce costs over previous single-layer-hinges. A mathematical model has been developed to predict the behavior of the hinges and tune them to the desired requirements. Experimental results show that the proposed hinges offer improved flexibility and durability compared to single-layer hinges, while reducing the manufacturing cost and complexity associated with multi-layer hinges. This research contributes to the advancement of foldable robotics by offering a simplified and cost-effective solution that can foster innovation in various applications.
ContributorsKanchan, Viraj (Author) / Aukes, Daniel (Thesis advisor) / Redkan, Sangram (Committee member) / Sugar, Thmas (Committee member) / Arizona State University (Publisher)
Created2023
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Description
Robot motion and control remains a complex problem both in general and inthe field of machine learning (ML). Without ML approaches, robot controllers are typically designed manually, which can take considerable time, generally requiring accounting for a range of edge cases and often producing models highly constrained to specific tasks. ML can decrease

Robot motion and control remains a complex problem both in general and inthe field of machine learning (ML). Without ML approaches, robot controllers are typically designed manually, which can take considerable time, generally requiring accounting for a range of edge cases and often producing models highly constrained to specific tasks. ML can decrease the time it takes to create a model while simultaneously allowing it to operate on a broader range of tasks. The utilization of neural networks to learn from demonstration is, in particular, an approach with growing popularity due to its potential to quickly fit the parameters of a model to mimic training data. Many such neural networks, especially in the realm of transformer-based architectures, act more as planners, taking in an initial context and then generating a sequence from that context one step at a time. Others hybridize the approach, predicting a latent plan and conditioning immediate actions on that plan. Such approaches may limit a model’s ability to interact with a dynamic environment, needing to replan to fully update its understanding of the environmental context. In this thesis, Language-commanded Scene-aware Action Response (LanSAR) is proposed as a reactive transformer-based neural network that makes immediate decisions based on previous actions and environmental changes. Its actions are further conditioned on a language command, serving as a control mechanism while also narrowing the distribution of possible actions around this command. It is shown that LanSAR successfully learns a strong representation of multimodal visual and spatial input, and learns reasonable motions in relation to most language commands. It is also shown that LanSAR can struggle with both the accuracy of motions and understanding the specific semantics of language commands
ContributorsHardy, Adam (Author) / Ben Amor, Heni (Thesis advisor) / Srivastava, Siddharth (Committee member) / Pavlic, Theodore (Committee member) / Arizona State University (Publisher)
Created2024
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Description
In today's world, robotic technology has become increasingly prevalent across various fields such as manufacturing, warehouses, delivery, and household applications. Planning is crucial for robots to solve various tasks in such difficult domains. However, most robots rely heavily on humans for world models that enable planning. Consequently, it is not

In today's world, robotic technology has become increasingly prevalent across various fields such as manufacturing, warehouses, delivery, and household applications. Planning is crucial for robots to solve various tasks in such difficult domains. However, most robots rely heavily on humans for world models that enable planning. Consequently, it is not only expensive to create such world models, as it requires human experts who understand the domain as well as robot limitations, these models may also be biased by human embodiment, which can be limiting for robots whose kinematics are not human-like. This thesis answers the fundamental question: Can we learn such world models automatically? This research shows that we can learn complex world models directly from unannotated and unlabeled demonstrations containing only the configurations of the robot and the objects in the environment. The core contributions of this thesis are the first known approaches for i) task and motion planning that explicitly handle stochasticity, ii) automatically inventing neuro-symbolic state and action abstractions for deterministic and stochastic motion planning, and iii) automatically inventing relational and interpretable world models in the form of symbolic predicates and actions. This thesis also presents a thorough and rigorous empirical experimentation. With experiments in both simulated and real-world settings, this thesis has demonstrated the efficacy and robustness of automatically learned world models in overcoming challenges, generalizing beyond situations encountered during training.
ContributorsShah, Naman (Author) / Srivastava, Siddharth (Thesis advisor) / Kambhampati, Subbarao (Committee member) / Konidaris, George (Committee member) / Speranzon, Alberto (Committee member) / Zhang, Yu (Committee member) / Arizona State University (Publisher)
Created2024