448 research outputs found
LiftTiles: Constructive Building Blocks for Prototyping Room-scale Shape-changing Interfaces
Large-scale shape-changing interfaces have great potential, but creating such
systems requires substantial time, cost, space, and efforts, which hinders the
research community to explore interactions beyond the scale of human hands. We
introduce modular inflatable actuators as building blocks for prototyping
room-scale shape-changing interfaces. Each actuator can change its height from
15cm to 150cm, actuated and controlled by air pressure. Each unit is low-cost
(8 USD), lightweight (10 kg), compact (15 cm), and robust, making it
well-suited for prototyping room-scale shape transformations. Moreover, our
modular and reconfigurable design allows researchers and designers to quickly
construct different geometries and to explore various applications. This paper
contributes to the design and implementation of highly extendable inflatable
actuators, and demonstrates a range of scenarios that can leverage this modular
building block.Comment: TEI 202
Continuum Mechanical Models for Design and Characterization of Soft Robots
The emergence of ``soft'' robots, whose bodies are made from stretchable materials, has fundamentally changed the way we design and construct robotic systems. Demonstrations and research show that soft robotic systems can be useful in rehabilitation, medical devices, agriculture, manufacturing and home assistance. Increasing need for collaborative, safe robotic devices have combined with technological advances to create a compelling development landscape for soft robots.
However, soft robots are not yet present in medical and rehabilitative devices, agriculture, our homes, and many other human-collaborative and human-interactive applications. This gap between promise and practical implementation exists because foundational theories and techniques that exist in rigid robotics have not yet been developed for soft robots. Theories in traditional robotics rely on rigid body displacements via discrete joints and discrete actuators, while in soft robots, kinematic and actuation functions are blended, leading to nonlinear, continuous deformations rather than rigid body motion.
This dissertation addresses the need for foundational techniques using continuum mechanics. Three core questions regarding the use of continuum mechanical models in soft robotics are explored: (1) whether or not continuum mechanical models can describe existing soft actuators, (2) which physical phenomena need to be incorporated into continuum mechanical models for their use in a soft robotics context, and (3) how understanding on continuum mechanical phenomena may form bases for novel soft robot architectures. Theoretical modeling, experimentation, and design prototyping tools are used to explore Fiber-Reinforced Elastomeric Enclosures (FREEs), an often-used soft actuator, and to develop novel soft robot architectures based on auxetic behavior.
This dissertation develops a continuum mechanical model for end loading on FREEs. This model connects a FREEâs actuation pressure and kinematic configuration to its end loads by considering stiffness of its elastomer and fiber reinforcement. The model is validated against a large experimental data set and compared to other FREE models used by roboticists. It is shown that the model can describe the FREEâs loading in a generalizable manner, but that it is bounded in its peak performance. Such a model can provide the novel function of evaluating the performance of FREE designs under high loading without the costs of building and testing prototypes. This dissertation further explores the influence viscoelasticity, an inherent property of soft polymers, on end loading of FREEs. The viscoelastic model developed can inform soft roboticists wishing to exploit or avoid hysteresis and force reversal. The final section of the dissertations explores two contrasting styles of auxetic metamaterials for their uses in soft robotic actuation. The first metamaterial architecture is composed of beams with distributed compliance, which are placed antagonistic configurations on a variety of surfaces, giving ride to shape morphing behavior. The second metamaterial architecture studied is a ``kirigamiââ sheet with an orthogonal cut pattern, utilizing lumped compliance and strain hardening to permanently deploy from a compact shape to a functional one.
This dissertation lays the foundation for design of soft robots by robust physical models, reducing the need for physical prototypes and trial-and-error approaches. The work presented provides tools for systematic exploration of FREEs under loading in a wide range of configurations. The work further develops new concepts for soft actuators based on continuum mechanical modeling of auxetic metamaterials. The work presented expands the available tools for design and development of soft robotic systems, and the available architectures for soft robot actuation.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163236/1/asedal_1.pd
The 15th Aerospace Mechanisms Symposium
Technological areas covered include: aerospace propulsion; aerodynamic devices; crew safety; space vehicle control; spacecraft deployment, positioning, and pointing; deployable antennas/reflectors; and large space structures. Devices for payload deployment, payload retention, and crew extravehicular activities on the space shuttle orbiter are also described
Origami surfaces for kinetic architecture
This thesis departs from the conviction that spaces that can change their
formal configuration through movement may endow buildings of bigger
versatility. Through kinetic architecture may be possible to generate adaptable
buildings able to respond to different functional solicitations in terms of the
used spaces.
The research proposes the exploration of rigidly folding origami surfaces as
the means to materialize reconfigurable spaces through motion. This specific
kind of tessellated surfaces are the result of the transformation of a flat
element, without any special structural skill, into a self-supporting element
through folds in the material, which gives them the aptitude to undertake
various configurations depending on the crease pattern design and welldefined
rules for folding according to rigid kinematics.
The research follows a methodology based on multidisciplinary, practical
experiments supported on digital tools for formal exploration and simulation.
The developed experiments allow to propose a workflow, from concept to
fabrication, of kinetic structures made through rigidly folding regular origami
surfaces. The workflow is a step-by-step process that allows to take a logical
path which passes through the main involved areas, namely origami geometry
and parameterization, materials and digital fabrication and mechanisms and
control.
The investigation demonstrates that rigidly folding origami surfaces can be
used as dynamic structures to materialize reconfigurable spaces at different
scales and also that the use of pantographic systems as a mechanism
associated to specific parts of the origami surface permits the achievement of
synchronized motion and possibility of locking the structure at specific stages
of the folding.A presente tese parte da convicção de que os espaços que são capazes de
mudar a sua configuração formal através de movimento podem dotar os
edifĂcios de maior versatilidade. AtravĂ©s da arquitectura cinĂ©tica pode ser
possĂvel a geração de edifĂcios adaptĂĄveis, capazes de responder a
diferentes solicitaçÔes funcionais, em termos do espaço utilizado.
Esta investigação propĂ”e a exploração de superfĂcies de origami, dobrĂĄveis
de forma rĂgida, como meio de materialização de espaços reconfigurĂĄveis
atravĂ©s de movimento. Este tipo de superfĂcies tesseladas sĂŁo o resultado da
transformação de um elemento plano, sem capacidade estrutural que, através
de dobras no material, ganha propriedades de auto-suporte. Dependendo do
padrĂŁo de dobragem e segundo regras de dobragem bem definidas de acordo
com uma cinemĂĄtica rĂgida, a superfĂcie ganha a capacidade de assumir
diferentes configuraçÔes.
A investigação segue uma metodologia baseada em experiĂȘncias prĂĄticas e
multidisciplinares apoiada em ferramentas digitais para a exploração formal e
simulação. AtravĂ©s das experiĂȘncias desenvolvidas Ă© proposto um processo
de trabalho, desde a conceptualização à construção, de estruturas cinéticas
baseadas em superfĂcies dobrĂĄveis de origami rĂgido de padrĂŁo regular. O
processo de trabalho proposto corresponde a um procedimento passo-apasso
que permite seguir um percurso lĂłgico que atravessa as principais
åreas envolvidas, nomeadamente geometria do origami e parametrização,
materiais e fabricação digital e ainda mecanismos e controle.
A dissertação demonstra que as superfĂcies de origami dobradas de forma
rĂgida podem ser utilizadas como estruturas dinĂąmicas para materializar
espaços reconfiguråveis a diferentes escalas. Demonstra ainda que a
utilização de sistemas pantogråficos como mecanismos associados a partes
especĂficas da superfĂcie permite atingir um movimento sincronizado e a
possibilidade de bloquear o movimento em estados especĂficos da dobragem
Transformable and transportable architecture: analysis of buildings components and strategies for project design
The present Master Thesis is a research about different aspects
of transformable transportable buildings, like components as
mechanisms for movement, building design strategies and construction
detailing, aimed a better understanding of the design and technical necessities
of this particular type of architecture.
The first application for transformable and transportable buildings were
developed during post-war period in an urge for solving housing problems
and the transformation of the industries, highly influenced by the
development of spatial structures. And until few years ago, the design of
this type of buildings was only focused on temporary structures or few
applications to real building solutions being pure concepts of futuristic
image but with the lack of technical development.
Recently, a new type of transportable and transformable architecture is
being produced as solutions for every-day-live use, and accepted in the
community they are inserted. In this type of projects the investigation is
going to be focused, analyzing from building components and connections
to technical design.La presente Tesis de MĂĄster es una investigaciĂłn que trata
sobre diferentes aspectos de edificios transformables y transportables,
tales como componentes como mecanismos para generar movimiento,
estrategias de diseño y detalles constructivos, enfocada en mejorar la
comprensión de las necesidad técnico-constructivas de este tipo particular
de arquitectura.
Las primeras aplicaciones de edificios transformables y transportables
fueron desarrolladas durante el perĂodo de posguerra como resultado
de la necesidad de solucionar problemas habitacionales y la transformaciĂłn
de las industrias, altamente influenciados por los avances de
las estructuras espaciales. Y hasta pocos años, el diseño de este tipo
de edificios era sĂłlo enfocado en estructuras temporales o pocas aplicaciones
a soluciones reales, siendo la mayorĂa puros conceptos con
una imagen futurĂstica pero con deficiencias en su desarrollo tĂ©cnico.
Recientemente, un nuevo tipo de arquitectura transportable y transformable
estĂĄ siendo producida, como soluciones para el uso diario y
aceptado por las comunidades donde son insertados. En este tipo de
proyectos se concentrarĂĄ la investigaciĂłn, analizando desde los componentes
y conexiones de los edificios hacia los aspectos técnicos del
diseño
Design and Fabrication of Soft 3D Printed Actuators: Expanding Soft Robotics Applications
Soft pneumatic actuators are ideal for soft robotic applications due to their innate compliance and high power-weight ratios. Presently, the majority of soft pneumatic actuators are used to create bending motions, with very few able to produce significant linear movements. Fewer can actively produce strains in multiple directions. The further development of these actuators is limited by their fabrication methods, specifically the lack of suitable stretchable materials for 3D printing.
In this thesis, a new highly elastic resin for digital light projection 3D printers, designated ElastAMBER, is developed and evaluated, which shows improvements over previously synthesised elastic resins. It is prepared from a di-functional polyether urethane acrylate oligomer and a blend of two different diluent monomers. ElastAMBER exhibits a viscosity of 1000 mPa.s at 40 °C, allowing easy printing at near room temperatures. The 3D-printed components present an elastomeric behaviour with a maximum extension ratio of 4.02 ± 0.06, an ultimate tensile strength of (1.23 ± 0.09) MPa, low hysteresis, and negligible viscoelastic relaxation
NASA Tech Briefs Index, 1977, volume 2, numbers 1-4
Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977
The development of microfluidic platforms for environmental analysis
There is currently a gap in the use of centrifugal microfluidics in the field environmental sensing. The purpose of this thesis was to develop new and innovative centrifugal microfluidic platforms, which could enhance current environmental monitoring strategy limitations; portability and in-situ capability, cost-effectiveness, generical design for multi-analyte detectability, and the minimal required end-user interaction. Included in the main body of the thesis will be a review article, providing the theoretical perspectives which have been demonstrated for microfluidic applications in other domains and recommendations for adaptation towards environmental sensing using centrifugal microfluidics, and three novel papers on the staged development of a multi- toxin detection platform aimed to be incorporated within the fully deployable MariaBox (Marine environmental in-situ assessment and monitoring toolBox, co-funded by the European Commission: contract no.614088) system. The aspects covered across these three original articles includes the development of a centrifugal microfluidic platform with complementary fluorescence detection system as an initial test bed for toxin bio- assay integration on-disc, progression of current centrifugally-automatable pneumatic microvalve mechanisms for increased actuation predictability, and the further combination of both of these detection and microvalve mechanisms for a complete on- disc, multi-toxin detection platform which has been designed specifically to be compatible with the deployable MariaBox platform
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