Untethered Microrobots of the Rolling, Jumping & Flying kinds

In this dissertation we study microrobot design for three modes of locomotion, namely rolling, jumping, and flying. This work covers power electronics, actuator and mechanical transmission design for these types of microrobots along with power source selection. Though interesting, we do not cover the sensors, controllers/computers, communications and useful payloads for these bots. This remains a topic for future work. Piezoelectric and electrostatic actuators generally have been the actuators of choice for researchers working in microrobotics, since conventional electromagnetic motor designs don't scale down well. Here we design an electromagnetic actuator in a way that significantly reduces its scaling down disadvantages, while still retaining its original advantages. This has enabled us to achieve untethered operation for our bots, which is one of the coveted goals for researchers working in this domain. Though untethered rolling and jumping is demonstrated, the untethered flying bot reported in this dissertation remains underpowered and doesn't take flight yet. First a micro-ratcheting mechanism is developed as a means to convert small periodic motions of actuators to continuous rotational motion. A supercapacitor, a fixed frequency H-bridge, and a low-voltage electromagnetic actuator is then used to drive this micro-ratchet to achieve untethered rolling motion for 8 seconds at 27mm/s. At 130mg mass, this is the lightest and fastest untethered rolling microrobot reported yet. The same continuous rotation mechanism developed for the rolling bot is then used to load a spring in an energy storage mechanism that can then release the stored energy rapidly and passively, via use of magnets, after the stored energy crosses a certain threshold. In this case, the continuous rotation mechanism is driven using laser-powered photovoltaic cells and untethered jumping up to heights of 8mm is demonstrated. At 75mg mass, it is the lightest untethered jumping microrobot with onboard power source. Next, a highly efficient resonant low-voltage electromagnetic actuator is developed to generate insect-like flapping wing motion. It is demonstrated to produce 90% of its weight in lift. Further light-weight and power-efficient power electronics are developed to power this actuator using laser-powered photovoltaic cells. The designed power electronics are an order of magnitude lighter and two orders of magnitude more efficient than all other power electronics units reported yet for flying microrobots. While sufficient lift for flight is not achieved, due to the actuator being underpowered because of power source overheating, untethered flapping wing motion is demonstrated. To provide inspiration to future generations of microroboticists, a fruit fly scale flapping winged robot is developed. At 0.7mg mass, even though tethered, it is the lightest and smallest bot to demonstrate flapping wing kinematics

Mechanical design and manufacturing of an insect-scale flapping-wing robot

Despite the prevalence of insect flight as a form of locomotion in nature, manmade aerial systems have yet to match the aerial prowess of flying insects. Within a tiny body volume, flying insects embody the capabilities to flap seemingly insubstantial wings at very high frequencies and sustain beyond their own body weight in flight. A precise authority over their wing motions enables them to respond to obstacles and threats in flight with unrivaled speed and grace. Motivated by a desire for comparably agile flying machines, research efforts in the last decade have generated crucial developments for realizing an artificial instantiation of insect flight. The need for tiny, high-efficiency mechanical components has produced unconventional solutions for propulsion, actuation, and manufacturing. Early vehicle designs proved to be flightworthy but were critically limited by the inability to produce control torques in flight. In this thesis, we synthesize all existing technologies for insect-scale manufacturing and actuation, and we introduce a new vehicle design, the "dual actuator bee," to address the need for flight control. Our work culminates in the first demonstration of controlled, hovering flight of an insect-scale, flapping-wing robot. As the ultimate goal for this research effort is the creation of fully autonomous flying robots, these vehicles must sustain their own power sources and intelligence. To that end, we explore the challenges of scaling flapping-wing flight to attain greater lift forces. Using a scaling heuristic to determine key vehicle specifications, we develop and successfully demonstrate a hover-capable vehicle design that possesses the requisite payload capacity for the full suite of components required for control autonomy. With this operational vehicle as a point of reference, we introduce an iterative sizing procedure for specifying a vehicle design with payload capacity capable of supporting power autonomy. In the development of these vehicles, the reliability of their construction has been a substantial challenge. We present strategies for systematically addressing issues of vehicle construction. Together, this suite of results demonstrates the feasibility of achieving artificial, insect-like flight.Engineering and Applied Sciences - Engineering Science

The Characterization of Material Properties and Structural Dynamics of the Manduca Sexta Forewing for Application to Flapping Wing Micro Air Vehicle Design

The Manduca Sexta species of moth serves as a source of biological inspiration for the future of micro air vehicle flapping flight. The ability of this species to hover in flapping flight has warranted investigation into the critical material, structural, and geometric properties of the forewing of this biological specimen. A rigorous morphological study of the Manduca Sexta forewing was conducted to characterize the physical and material properties of the biological forewing for the purpose of developing an advanced parametric three dimensional model finite element analysis (FEA) model. This FEA model was tuned to match the experimentally determined structural dynamics of the biological specimen and serves as the basis for an engineered wing design. Manufacturing methods are developed and implemented to fabricate the baseline engineered wing design. Biological wings and engineered wings are experimentally tested to determine the aerodynamic lift production of each of wings under the same boundary conditions. Through this research, a structural dynamics based engineering methodology has been used to design, develop, and identify biomimetic engineered wings that experimentally produce aerodynamic forces equivalent to their biological analog

IMPROVED PREDICTION OF FLAPPING WING AERIAL VEHICLE PERFORMANCE THROUGH COMPONENT INTERACTION MODELING

Flapping wing aerial vehicles offer the promise of versatile performance, however prediction of flapping wing aerial vehicle performance is a challenging task because of complex interconnectedness in vehicle functionality. To address this challenge, performance is estimated by using component-level modeling as a foundation. Experimental characterization of the drive motors, battery, and wings is performed to identify important functional characteristics and enable selection of appropriate modeling techniques. Component-level models are then generated that capture the performance of each vehicle component. Validation of each component-level model shows where errors are eliminated by capturing important dynamic functionality. System-level modeling is then performed by creating linkages between component-level models that have already been individually validated through experimental testing, leading to real-world functional constraints that are realized and correctly modeled at the system level. The result of this methodology is a system-level performance prediction that offers the ability to explore the effects of changing vehicle components as well as changing functional properties, while maintaining computational tractability. Simulated results are compared to experimental flight test data collected with an instrumented flapping wing aerial vehicle, and are shown to offer good accuracy in estimation of system-level performance properties

Design and Performance of Insect-Scale Flapping-Wing Vehicles

Micro-air vehicles (MAVs)—small versions of full-scale aircraft—are the product of a continued path of miniaturization which extends across many fields of engineering. Increasingly, MAVs approach the scale of small birds, and most recently, their sizes have dipped into the realm of hummingbirds and flying insects. However, these non-traditional biologically-inspired designs are without well-established design methods, and manufacturing complex devices at these tiny scales is not feasible using conventional manufacturing methods. This thesis presents a comprehensive investigation of new MAV design and manufacturing methods, as applicable to insect-scale hovering flight. New design methods combine an energy-based accounting of propulsion and aerodynamics with a one degree-of-freedom dynamic flapping model. Important results include analytical expressions for maximum flight endurance and range, and predictions for maximum feasible wing size and body mass. To meet manufacturing constraints, the use of passive wing dynamics to simplify vehicle design and control was investigated; supporting tests included the first synchronized measurements of real-time forces and three-dimensional kinematics generated by insect-scale flapping wings. These experimental methods were then expanded to study optimal wing shapes and high-efficiency flapping kinematics. To support the development of high-fidelity test devices and fully-functional flight hardware, a new class of manufacturing methods was developed, combining elements of rigid-flex printed circuit board fabrication with "pop-up book" folding mechanisms. In addition to their current and future support of insect-scale MAV development, these new manufacturing techniques are likely to prove an essential element to future advances in micro-optomechanics, micro-surgery, and many other fields.Engineering and Applied Science

Flapping Wing Micro Air Vehicle Wing Manufacture and Force Testing

Numerous wing manufacturing techniques have been developed by various universities for research on Flapping Wing Micro Air Vehicles. Minimal attention though is given to repeatability of wing aerodynamics and dynamic response, which is crucial to avoid asymmetric flapping. Thus the focus of this research becomes twofold. First, repeatable wing manufacturing techniques are developed to ensure flapping wings have similar aerodynamic and dynamic characteristics. For this purpose, four wing designs were selected to not only test the aerodynamics of the different designs, but to also validate manufacturing techniques. The various wing designs are assessed using two methods: dynamic and aerodynamic data. Dynamic data, specifically the wing\u27s structural dynamic response, is measured using a 3D laser vibrometer. From this vibration data, the wings natural frequency modes can be determined which should correlate strongly within the various wing designs if the manufacturing techniques are repeatable. Next, using a piezoelectric flapping actuator, the four wing designs are flapped with force data collected. This data is then used to determine the aerodynamic characteristics of each wing. From the two methods of wing evaluation, it was found that the wings manufactured using a three-layer carbon layup showed greater structural dynamic modal repeatability as compared to one-layer carbon wings. Additionally, Wing Design 3 flapped with the most efficiency with a significantly higher lift to drag ratio as compared to the other wing designs. From this research, the wing manufacturing techniques are quantitatively shown to be repeatable while an optimal wing design based on the maximum lift-to-drag ratio is found which can be used for future research

Advances in Bio-Inspired Robots

This book covers three major topics, specifically Biomimetic Robot Design, Mechanical System Design from Bio-Inspiration, and Bio-Inspired Analysis on A Mechanical System. The Biomimetic Robot Design part introduces research on flexible jumping robots, snake robots, and small flying robots, while the Mechanical System Design from Bio-Inspiration part introduces Bioinspired Divide-and-Conquer Design Methodology, Modular Cable-Driven Human-Like Robotic Arm andWall-Climbing Robot. Finally, in the Bio-Inspired Analysis on A Mechanical System part, research contents on the control strategy of Surgical Assistant Robot, modeling of Underwater Thruster, and optimization of Humanoid Robot are introduced

Research and technology 1991 annual report

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, NASA Kennedy is placing increasing emphasis on the center's research and technology program. In addition to strengthening those areas of engineering and operations technology that contribute to safer, more efficient, and more economical execution of the current mission, the technical tools are being developed which are needed to execute the center's mission relative to future programs. The Engineering Development Directorate encompasses most of the labs and other center resources that are key elements of research and technology program implementation and is responsible for implementation of the majority of the projects in this Kennedy Space Center 1991 annual report

PROGRAM and PROCEEDINGS THE NEBRASKA ACADEMY OF SCIENCES: 139th Anniversary Year, One Hundred-Twenty-Ninth Annual Meeting, April 12, 2019, NEBRASKA WESLEYAN UNIVERSITY, LINCOLN, NEBRASKA

PROGRAM AT-A-GLANCE FRIDAY, APRIL 12, 2019 7:30 a.m. REGISTRATION OPENS - Lobby of Lecture Wing, Olin Hall 8:00 Aeronautics and Space Science, Session A – Acklie 109 Aeronautics and Space Science, Session B – Acklie 111 Collegiate Academy; Biology, Session B - Olin B Biological and Medical Sciences, Session A - Olin 112 Biological and Medical Sciences, Session B - Smith Callen Conference Center Chemistry and Physics; Chemistry - Olin A 8:00 “Teaching and Learning the Dynamics of Cellular Respiration Using Interactive Computer Simulations” Workshop – Olin 110 9:30 “Life After College: Building Your Resume for the Future” Workshop – Acklie 218 8:25 Collegiate Academy; Chemistry and Physics, Session A – Acklie 007 8:36 Collegiate Academy; Biology, Session A - Olin 111 9:00 Chemistry and Physics; Physics – Acklie 320 9:10 Aeronautics and Space Science, Poster Session – Acklie 109 & 111 10:30 Aeronautics and Space Science, Poster Session – Acklie 109 & 111 11:00 MAIBEN MEMORIAL LECTURE: Dr David Swanson - OLIN B Scholarship and Friend of Science Award announcements 12:00 p.m. LUNCH – WESLEYAN CAFETERIA Round-Table Discussion – “Assessing the Academy: Current Issues and Avenues for Growth” led by Todd Young – Sunflower Room 12:50 Anthropology – Acklie 109 1:00 Applied Science and Technology - Olin 111 Biological and Medical Sciences, Session C - Olin 112 Biological and Medical Sciences, Session D - Smith Callen Conference Center Chemistry and Physics; Chemistry - Olin A Collegiate Academy; Biology, Session B - Olin B Earth Science – Acklie 007 Environmental Sciences – Acklie 111 Teaching of Science and Math – Acklie 218 1:20 Chemistry and Physics; Physics – Acklie 320 4:30 BUSINESS MEETING - OLIN B NEBRASKA ASSOCIATION OF TEACHERS OF SCIENCE (NATS) The 2019 Fall Conference of the Nebraska Association of Teachers of Science (NATS) will be held at the Younes Conference Center, Kearney, NE, September 19-21, 2019. President: Betsy Barent, Norris Public Schools, Firth, NE President-Elect: Anya Covarrubias, Grand Island Public Schools, Grand Island, NE AFFILIATED SOCIETIES OF THE NEBRASKA ACADEMY OF SCIENCES, INC. 1. American Association of Physics Teachers, Nebraska Section Web site: http://www.aapt.org/sections/officers.cfm?section=Nebraska 2. Friends of Loren Eiseley Web site: http://www.eiseley.org/ 3. Lincoln Gem & Mineral Club Web site: http://www.lincolngemmineralclub.org/ 4. Nebraska Chapter, National Council for Geographic Education 5. Nebraska Geological Society Web site: http://www.nebraskageologicalsociety.org Sponsors of a $50 award to the outstanding student paper presented at the Nebraska Academy of Sciences Annual Meeting, Earth Science /Nebraska Chapter, Nat\u27l Council Sections 6. Nebraska Graduate Women in Science 7. Nebraska Junior Academy of Sciences Web site: http://www.nebraskajunioracademyofsciences.org/ 8. Nebraska Ornithologists’ Union Web site: http://www.noubirds.org/ 9. Nebraska Psychological Association http://www.nebpsych.org/ 10. Nebraska-Southeast South Dakota Section Mathematical Association of America Web site: http://sections.maa.org/nesesd/ 11. Nebraska Space Grant Consortium Web site: http://www.ne.spacegrant.org