Thesis (Ph. D.)--University of Wisconsin--Madison, 1976. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 157-165).

Thesis (Ph.D.), Memorial University of Newfoundland, 2000. / Bibliography: leaves 190-199.

The use of origami-based bellows is of interest in fields where traditional metal bellows are incapable of meeting compression, mass, or flexibility constraints. Metal bellows are often used in space applications but frequently complicate spacecraft design. Origami-based bellows capable of meeting design constraints while adequately shielding sensitive spacecraft parts may be advantageous to space mechanism design. The design and testing of a highly compressible origami bellows for harsh environments is described. Several origami patterns were evaluated and the Kresling fold pattern was designed to meet constraints and selected for use in the bellows design. Origami bellows were prototyped in five different materials and tested in fatigue, thermal cycling, ablation, and radiation. Tested bellows show good fatigue life exceeding 100,000 cycles for some materials and resilience to potential harsh environmental conditions such as thermal cycling, abrasion, and high radiation. The bellows can be designed to fit within a given inner and outer diameter and stroke length depending on the design requirements. The origami bellows shows promise for space application and as an adequate replacement for current metal bellows due to its high compressibility and low mass. The design, testing, and fabrication of an origami-based bellows for microgravity drilling is presented. The benefits of origami created an opportunity for application on NASA's Asteroid Redirect Mission (ARM) to protect sensitive parts from debris. Origami-based bellows were designed to fit spacial limitations and meet needed compression ratios. Designs have demonstrated high mass reductions, improved stroke length, greatly decreased stowed volume, improved flexibility, and reduced reaction forces in comparison with traditional metal bellows. Material and design testing demonstrated that a nylon-reinforced polyvinyl fluoride based bellows with an aramid fiber stitched seam is well suited for debris containment in space conditions. Various epoxies were able to maintain an adequate bond with polyvinyl fluoride below expected environmental temperature for bellows mounting to the ARM drill. Asymmetric compression of the bellows can occur at extreme low temperatures and is preventable by balancing stiffness within the structure.

For increase productivity, the current technology of welding pipes bellows was replaced by laser welding. Experiment was carried out on the material of austenitic stainless steel 1.4541 for sheet thickness 0.25 mm and 0.15 mm. On sheet 0.25 mm was achieved comparable mechanical properties as the current manufacturing process upon achieving 10 times higher welding speeds. Samples of 0.15 mm thickness achieved to about 30% lower deepening over existing technology. For improvement was advised to reduce heat input. From an economic assessment shows that the price per 1 m of weld decreases with increasing speed welding. With higher welding speeds reduces the heat input.

The objective of this research is to develop a design process for origami-adapted products and demonstrate it using aerospace mechanism examples. Origami-adapted design is a type of origami-based design. Origami-based design ranges from abstract to concrete applications of origami to design and includes: origami-inspired design, origami-adapted design, and origami-applied design. Origami-adapted design adapts origami fold patterns into products while preserving functionality. Some of the desirable attributes of origami that are sought after in design include: 1) reduced number of parts, 2) stowability, 3) deployability, 4) transportability, 5) manufacturability from a flat sheet of material, 6) ease of miniaturization, 7) a single manufacturing technique (folding) and 8) low material volume and mass. The proposed origami-adapted design process has four steps: define the problem, identify an origami solution, modify the fold pattern, and integrate. Intermediate steps apply tools to analyze and modify the origami fold pattern according to the design requirements. The first step defines whether origami is a viable solution by evaluating a set of starting criteria. Once it has been determined that origami is a viable solution, the design process guides the designer through a series of steps that modify the origami crease pattern until the final design is reached. The origami-adapted design process is applied to the design of three aerospace mechanism examples: an origami bellows, an expandable habitat, and a deployable parabolic antenna. The design process is followed throughout the design of these aerospace mechanisms. The origami bellows is designed and tested as a highly compressible origami bellows for harsh environments. It can be designed to endure 100,000+ cycles in fatigue and underwent testing for thermal cycling, abrasion, and radiation. The second example is a proof-of-concept expandable habitat for implementation as a module on the International Space Station. The design process aides in selecting an origami crease pattern and modifying it for thick, rigid materials. The last example is a deployable parabolic antenna. It is based on the flasher fold pattern with a wedge of the pattern removed to create curvature. It is experimentally verified to be approximately parabolic. The examples are shown to follow the origami-adapted design process and that the design process is flexible to accommodate a design's needs.

Numerous spacecraft designs exist for exploring the surfaces of planetary bodies and each have their own advantages and disadvantages. All successful landings have been made by stationary landers or wheeled rovers that rely on one-time use mechanisms, such as crushable aluminum honeycomb shock absorbers or inflatable airbags, to reduce shock loading to the spacecraft during landing. The stationary lander is the simplest type of lander, but can only take data from one location. Wheeled rovers add complexity in exchange for mobility to explore different locations. Rovers are limited by the terrain they can traverse; rovers becoming stuck have ended missions. In contrast to rovers and stationary landers, hoppers explore by making multiple launch and landing hops. They have the advantage of being able to avoid terrain that would cause a rover to become stuck. A hopper may require a landing shock absorber that can reliably operate multiple times in harsh environments. Most terrestrial shock absorbers use hydraulic fluid, allowing for compact and inexpensive devices. Hydraulics have been used in space applications, but require thermal controls to maintain the proper fluid viscosity. They also require dynamic seals which, in the case of a leak, can degrade performance, shorten mission life, and contaminate sensitive science equipment. Leakage is also a concern in pressurized systems in space because missions can take decades from when a system is installed to when it actually is used. To address these issues, a pressurized metal bellows shock absorber is proposed. This shock absorber could operate at nearly any expected spacecraft environment. Metal bellows are designed to operate from cryogenic temperatures to several hundred degrees Celsius. A hermetically sealed system eliminates the risks of a system with seals. Metal bellows are in common use for terrestrial harsh environments and vacuum applications. Small metal bellows are used as dampers for pressure control systems with small displacements. Models for the dynamics of this device are developed and presented here. Starting from the ideal gas law, polytropic compression, and compressible flow through an orifice, differential equations of motion and pressure are derived. These equations are nonlinear for the displacements under consideration and are nondimensionalized to help provide insight. Equations for static equilibrium, maximum initial displacement bounds, and estimated natural frequency are presented. Metal bellows can operate as a passive damper with a simple orifice between the control volumes. Optimization is performed for the nondimensional model of a passive damper. Because the response is highly nonlinear, a method is developed to estimate a damping coefficient that is used as the objective function for this optimization. Feasibility of this concept is investigated through an example design problem using data from a metal bellows manufacturer as constraints. An optimal mass configuration is found that meets the design constraints. Performance can be improved over the passive system by adding control. The first control strategy involves a check valve, such that the effective orifice size varies between compression and extension. The next control strategy replaces the orifice with a control valve. Varying the valve opening and closing timing can achieve optimal performance. Finally, using the metal bellows as an actuator to help launch the hopper is investigated. While the valve is closed, the gas in the second volume is compressed. Then the valve is opened the hopper is launched. The results of this research show that a metal bellows device holds promise as a landing shock absorber and launch actuator to extend the range of hopper spacecraft.

Soft robotic systems have recently been considered as a new approach that is in principle better suited for tasks where safety and adaptability are important. That is because soft materials are inherently compliant and resilient in the event of collisions. They are also lightweight and can be low-cost; in general, soft robots have the potential to achieve many tasks that were not previously possible with traditional robotic systems. In this paper, we propose a new manufacturing process for creating multi-chambered pneumatic actuators and robots. We focus on using fabric as the primary structural material, but plastic films can be used instead of textiles as well. We introduce two different methods to create layered bellows actuators, which can be made with a heat press machine or in an oven. We also describe origami-like actuators with possible corner structures. Moreover, the fabrication process permits the creation of soft and soft/rigid hybrid robotic systems, and enables the easy integration of sensors into these robots. We analyze various textiles that are possibly used with this method, and model bellows actuators including operating force, restoring force, and estimated geometry with multiple bellows. We then demonstrate the process by showing a bellows actuator with an embedded sensor and other fabricated structures and robots. We next present a new design of a multi-DOF soft/rigid hybrid robotic manipulator. It contains a revolute actuator and several roll-pitch actuators which are arranged in series. To control the manipulator, we use a new variant of the piece-wise constant curvature (PCC) model. The robot can be controlled using forward and inverse kinematics with embedded inertial measurement units (IMUs). A bellows actuator, which is a subcomponent of the manipulator, is modeled with a variable-stiffness spring, and we use the model to predict the behavior of the actuator. With the model, the roll-pitch actuator stiffnesses are measured in all directions through applying forces and torques. The stiffness is used to predict the behavior of the end effector. The robotic system introduced achieved errors of less than 5% when compared to the models, and positioning accuracies of better than 1cm. / Doctor of Philosophy / Future robotic systems are expected to deal with many tasks in real-world environments. The natural environment is highly unpredictable and unstructured, making manipulation and locomotion challenging for robots. Robots need to rely on adaptability, reconfigurability, and safety. Soft robotic systems have recently been considered as a new approach that is in principle better suited for tasks where safety and adaptability are important. That is because soft materials are inherently compliant and resilient in the event of collisions. They are also lightweight and can be low-cost; in general, soft robots have the potential to achieve many tasks that were not previously possible with traditional robotic systems. In this paper, we propose a new manufacturing process for creating multi-chambered pneumatic actuators and robots. We focus on using fabric as the primary structural material, but plastic films can be used instead of textiles as well. We introduce two different methods to create layered bellows actuators, which can be made with a heat press machine or household iron, or in an oven. We also describe origami-like actuators with possible corner structures. Moreover, the fabrication process permits the creation of soft and soft/rigid hybrid robotic systems, and enables the easy integration of sensors into these robots. We analyze various textiles that can be used with this method, and make models of bellows actuators including their operating force, restoring force, and estimated geometry with multiple bellows. We then demonstrate the process by showing a bellows actuator with an embedded sensor and other fabricated structures and robots. We next present a new design of a multi-DOF soft/rigid hybrid robotic manipulator. It contains a revolute actuator and several roll-pitch actuators which are arranged in series. To control the manipulator, we use a new variant of the piece-wise constant curvature (PCC) model. The robot can be controlled using forward and inverse kinematics with embedded inertial measurement units (IMUs). A bellows actuator, which is a subcomponent of the manipulator, is modeled with a variable-stiffness spring, and we use the model to predict the behavior of the actuator. With the model, the roll-pitch actuator stiffnesses are measured in all directions through applying forces and torques. The stiffness is used to predict the behavior of the end effector.

Monitoring accurate temperature and pressure profiles in harsh environments is currently in high demand in aerospace gas turbine engines and nuclear reactor simulators. Having the ability to measure both quantities continuously over a region, without thermal coupling, using a sensor with a small size (envelope) is also highly desirable. Currently available MEMS (microelectromechanical systems) provide effective small scale pressure and temperature measurement devices, however, they have only been shown to be effective up to 600C and lack the ability to perform distributed measurements unless combined with fiber-optic techniques. In general, fiber-optics provide many advantages over electrical based sensors and are the ideal choice for high temperature regimes and distributed sensing. In this thesis, preliminary designs and suggested future work are presented for a sensor built within an 3.175 mm radius envelope and capable of distributed pressure and temperature sensing up to temperatures reaching 800C. Finite element analysis via ANSYS, along with analytical verification models have been used for the design evolution. Diaphragm based designs, seem to provide easy fabrication methods and good sensitivity, however, for this design to be realized at high temperature operation, a robust bonding method must be chosen to avoid unwanted deformation due to misfit strains. / Master of Science

På Scania RTCC önskas högre kontroll och precision på dess luftbälgar vid simulering i AdamsCar. Därför har uppdrag tagits fram för att modellera luftbälgar från dragbilens hytt ochhjulupphängning. Till arbetet ingick test av tre luftbälgar som genomgick belastningsmätning i rigg. Modellens struktur togs fram av tre delar som empirisk areamodell Ae, teoretisk tryckmodell P’och empirisk volymmodell VK. Empirisk modell av effektiva arean Ae togs från mätningarna så samband mellan tryck ochkraft kan användas. För att undvika reglerteknisk modellering försummas hysteresen såmodellen blir reversibel. Rapporten kombinerade två av litteraturens tryckmodeller till en egen så samband fåsmellan tryckets förändring P’, luftmassans förändring m’ och volymens relativa förändringVK. Tryckmodellen har med avsikt inte gjorts beroende av volymen eller temperaturen dåmätning av dessa storheter saknas. Temperaturens inverkan på bälgen förenklas tillhastighetskonstanten n som är 1 för mycket långsam körning och 1,4 för normal körning. För att undvika bälgens volym modelleras den relativa volymförändringen VK från trycketsteori samt de empiriska mätningarna. Här idealiseras förändringen på samma sätt som förarean Ae till att vara reversibel genom att ta bort hysteresen. Modellens sammansatta ekvation ger ett lagom enkelt samband för kraftens förändring hos bälgen:Kraftmodellen har förenklingar som ger kända och okända fel. Utan hysteres fås 1,5 % fel viddynamisk körning och antagandet av konstant volym vid förändrad massa ger okända fel. Trotsdet rekomenderas att modellen avänds och utvecklas vidare så felen och osäkerheten minskas. / Scania RTCC requires greater control and precision on its air bellows when simulated in Adams Car. Therefore, assignments have been developed to model air bellows from the trailer's cab andwheel suspension. The work included tests of three air bellows that underwent load deformation. The structure of the model was developed by three parts as empirical area model Ae, theoreticalpressure model P' and empirical volume model VK. Empirical model of the effective area Ae was shaped by measurements so that pressureto-force relationship can be used. To avoid control engineering modeling, the hysteresisis neglected so the model becomes reversible. The report combined two of the literature's pressure models to a new model betweenchange in pressure P', change in air mass m' and change in relative volume VK. Themodel is intentionally independent of the volume or temperature where measurement ofthese have not been taken. The effect of the temperature on the bellows is simplified tothe speed constant n which is 1 for slow driving and 1,4 for normal driving. To avoid the volume of the air bellows, the relative change in volume VK is modeledfrom the pressure model and the empirical measurements. VK is simplified in the manneras for the area Ae by removing the hysteresis and making it reversible. Put together, the model provides a fairly easy theory of the force's change in the air bellows from the equation underneath. The force model has simplifications that give known and unknown errors. Without hysteresis,deviations of 1,5% are obtained during dynamic driving, and the assumption of constant volumeat changed mass gives unknown errors. It is the reports recommendation that the model beimplemented and further developed so that the errors and uncertainties are reduced.

This work consists in the development and design of an energy harvesting device to supply power to the new generation pacemakers, miniaturized leadless implants without battery placed directly in heart chambers. After analyzing different mechanical energy sources in the cardiac environment and associated energy harvesting mechanisms, a concept based on regular blood pressure variation stood out: an implant with a flexible packaging that transmits blood forces to an internal transducer. Advantages compared to traditional inertial scavengers are mainly: greater power density, adaptability to heartbeat frequency changes and miniaturization potential. Ultra-flexible 10-µm thin metal bellows have been designed, fabricated and tested. These prototypes acting as implant packaging that deforms under blood pressure actuation have validated the proposed harvesting concept. A new type of electrostatic transducer (3D multi-layer out-of-plane overlap structure with interdigitated combs) has been introduced and fully analyzed. Promising numerical results and associated fabrication processes are presented. Also, large stroke optimized piezoelectric spiral transducers including their complex electrodes patterns have been studied through a design analysis, numerical simulations, prototype fabrication and experimental testing. Apower density of 3 µJ/cm3/cycle has been experimentally achieved. With further addressed developments, the proposed device should provide enough energy to power autonomously and virtually perpetually the next generation of pacemakers.