Tensegrity Principle Research Articles

Tensegrity FlaxSeat: Exploring the Application of Unidirectional Natural Fiber Biocomposite Profiles in a Tensegrity Configuration as a Concept for Architectural Applications

Material selection is crucial for advancing sustainability in the building sector. While composites have become popular, biocomposites play a pivotal role in raising awareness of materials deriving from biomass resources. This study presents a new linear biocomposite profile, fabricated using pultrusion technology, a continuous process for producing endless fiber-reinforced composites with consistent cross-sections. The developed profiles are made from flax fibers and a plant-based resin. This paper focuses on the application of these profiles in tensegrity systems, which combine compression and tension elements to achieve equilibrium. In this study, the biocomposite profiles were used as compression elements, leveraging their properties. The methods include geometrical development using physical and digital models to optimize the geometry based on material properties and dimensions. A parametric algorithm including physics simulations was developed for this purpose. Further investigations explore material options for tension members and connections, as well as assembly processes. The results include several prototypes on different scales. Initially, the basic tensegrity principle was built and explored. The lessons learned were applied in a final prototype of 1.5 m on a furniture scale, specifically a chair, integrating a hanging membrane serving as a seat. This structure validates the developed system, proving the feasibility of employing biocomposite profiles in tensegrity configurations. Furthermore, considerations for scaling up the systems to an architectural level are discussed, highlighting the potential to enhance sustainability through the use of renewable and eco-friendly building materials, while promoting tensegrity design applications.

Form-Finding and Evaluation of Spherical Tensegrity Toward Applying in Locomotive Robots

Abstract A tensegrity-based robot is a locomotive robot that operates on the principle of tensegrity, allowing it to change its shape by adjusting its internal prestress. Tensegrity-based robots can be categorized into different types based on their shape, with the spherical tensegrity-based robot garnering the most attention. However, existing designs for spherical tensegrity-based robots tend to be relatively simple and lack standardized criteria for evaluating their performance. This paper proposes an optimization approach using the force density method to design new spherical regular tensegrity configurations. This is achieved by parameterizing the topology and configuration of the structure, taking into account structural symmetry and the even distribution of internal forces. The proposed approach generates not only classical tensegrities but also novel configurations suitable for locomotive robots. To preliminarily evaluate the suitability of classical tensegrities and novel tensegrities to be used as a rolling robot, a set of performance indexes, including inner space, compactability, prestress evenness, gait repeatability, tilt stability ratio, stride length, and path efficiency, are proposed. The proposed indexes can be quickly determined based on the geometry of the tensegrity and thus are useful in the conceptual selection of the spherical tensegrities for rolling robots. They are used to evaluate a set of six spherical tensegrities. Numerical simulations are carried out to verify the feasibility of geometry-based approximating the gait-dependent indexes. Through the evaluation, a novel spherical tensegrity consisting of 15 struts and 60 tendons is identified as a promising candidate for rolling robots.

Assessment of Selected Trunk and Neck Muscle Activity in Children with Idiopathic Toe Walking

Introduction: Analyses related to idiopathic toe walking (ITW) are limited to the functioning of the lower-limb. It is recommended to broaden our understanding and consider other parts of the body in accordance with the principles of tensegrity.

Kinetostatic Analysis of a Spatial Cable-Actuated Variable Stiffness Joint

Abstract The demand for robots capable of performing collaborative tasks requiring interactions with the environment is on the rise. Safe interactions with the environment require attributes such as high dexterity and compliance around obstacles, while still maintaining the requisite stiffness levels for payload manipulation. Such attributes are inherent to biological musculoskeletal systems. Motivated by this realization, this paper proposes a cable-actuated spatial joint with variable stiffness, inspired by the tensegrity principles found in biological musculoskeletal systems. The paper provides a detailed analysis of the joint’s mobility and mechanism kinematics. Based on the limits of the actuation forces, the paper also presents the wrench-feasible workspace of the joint. The paper also outlines the conditions that the cable actuation forces must satisfy to maintain the static equilibrium of the joint. The stiffness modeling presented in this work demonstrates the modulation of stiffness bounds as a function of cable actuation forces. Furthermore, the stiffness modulation as a function of the geometrical parameters is also presented.

The principle of tensegrity as the basis of health nowadays

The article examines the principle of "tensegrity" as the basis of health nowadays. The existence of such approaches to the study of health problems as: norm-centric, phenomenological, holistic, discursive, integrative, evolutionist, socially-oriented, norm-centric, phenomenological are mentioned. The problem of formation and preservation of health is one of the main and urgent problems of humanity today. The desire to increase its level leads to the need to constantly review the issue of health formation, search for more effective health systems and methods, and develop new health care technologies.
 It has been established that this term refers to structures whose integrity is maintained due to the balance between the forces of constant tension. It has been proven that problems in one area of the body can be caused by existing clamps in other parts of the body. Pathology occurs either as a result of congenital weakness, or a previous injury or due to compression in a certain part of the human body. Our whole body is built according to the principle of "tensegrity" and if there is an imbalance in certain organs or structures there will be a violation of the state of health that would accurately and accurately identify the causes of health disorders in the early stages, and could be eliminated with the help of safe action algorithms.

Suggesting a mechanism for acupuncture as a global percutaneous needle fasciotomy that respects tensegrity principles for treating fibromyalgia.

Acupuncture is a minimally invasive therapeutic method that uses small caliber needles while inserting them through the skin into various areas of the body. Some empirical studies find evidence to support the use of acupuncture as a treatment for certain medical conditions, however, this peculiar practice is widely considered as the domain of alternative and non-evidence-based medicine. Several mechanisms have been suggested in an attempt to explain the therapeutic action of acupuncture, but the way in which acupuncture alleviates chronic non-cancer pain or psychosomatic and psychiatric disorders is not fully understood. A recent study suggested a theoretical model (coined "Fascial Armoring") with a cellular pathway to help explain the pathogenesis of myofascial pain/fibromyalgia syndrome and functional psychosomatic syndromes. It proposes that these syndromes are a spectrum of a single medical entity that involves myofibroblasts with contractile activity in fascia and aberrant extracellular matrix (ECM) remodeling, which may lead to widespread mechanical tension and compression. This can help explain diverse psycho-somatic manifestations of fibromyalgia-like syndromes. Fascia is a continuous interconnected tissue network that extends throughout the body and has qualities of bio-tensegrity. Previous studies show that a mechanical action by needling induces soft tissue changes and lowers the shear modulus and stiffness in myofascial tissue. This hypothesis and theory paper offers a new mechanism for acupuncture therapy as a global percutaneous needle fasciotomy that respects tensegrity principles (tensegrity-based needling), in light of the theoretical model of "Fascial Armoring." The translation of this model to other medical conditions carries potential to advance therapies. These days opioid overuse and over-prescription are ubiquitous, as well as chronic pain and suffering.

Scoping review and interpretation of myofascial pain/fibromyalgia syndrome: An attempt to assemble a medical puzzle.

BackgroundMyofascial Pain Syndrome (MPS) is a common, overlooked, and underdiagnosed condition and has significant burden. MPS is often dismissed by clinicians while patients remain in pain for years. MPS can evolve into fibromyalgia, however, effective treatments for both are lacking due to absence of a clear mechanism. Many studies focus on central sensitization. Therefore, the purpose of this scoping review is to systematically search cross-disciplinary empirical studies of MPS, focusing on mechanical aspects, and suggest an organic mechanism explaining how it might evolve into fibromyalgia. Hopefully, it will advance our understanding of this disease.MethodsSystematically searched multiple phrases in MEDLINE, EMBASE, COCHRANE, PEDro, and medRxiv, majority with no time limit. Inclusion/exclusion based on title and abstract, then full text inspection. Additional literature added on relevant side topics. Review follows PRISMA-ScR guidelines. PROSPERO yet to adapt registration for scoping reviews.Findings799 records included. Fascia can adapt to various states by reversibly changing biomechanical and physical properties. Trigger points, tension, and pain are a hallmark of MPS. Myofibroblasts play a role in sustained myofascial tension. Tension can propagate in fascia, possibly supporting a tensegrity framework. Movement and mechanical interventions treat and prevent MPS, while living sedentarily predisposes to MPS and recurrence.ConclusionsMPS can be seen as a pathological state of imbalance in a natural process; manifesting from the inherent properties of the fascia, triggered by a disrupted biomechanical interplay. MPS might evolve into fibromyalgia through deranged myofibroblasts in connective tissue (“fascial armoring”). Movement is an underemployed requisite in modern lifestyle. Lifestyle is linked to pain and suffering. The mechanism of needling is suggested to be more mechanical than currently thought. A “global percutaneous needle fasciotomy” that respects tensegrity principles may treat MPS/fibromyalgia more effectively. “Functional-somatic syndromes” can be seen as one entity (myofibroblast-generated-tensegrity-tension), sharing a common rheuma-psycho-neurological mechanism.

Tensegrital wheel for enhanced planetary surface mobility: Part 1 – Design and evolution

This paper follows ProtoInnovations’ development of a line of novel wheel concepts built with tensegrity principles for planetary mobility. The goal of these tensegrital wheels for enhanced planetary surface mobility is to exploit the geometric and mechanical attributes of tensegrity to mimic the compliant and load-distributing properties of a pneumatic tire using space-qualified methods and materials. In this paper we present our tensegrity design process and the evolution of our tensegrital wheel concepts. We conclude with an exploration of the tensegrital wheel’s potential with regards to planetary exploration applications and summarize considerations and improvements for future tensegrital wheel research.

3D Cell Culture for the Study of Microenvironment-Mediated Mechanostimuli to the Cell Nucleus: An Important Step for Cancer Research.

The discovery that the stiffness of the tumor microenvironment (TME) changes during cancer progression motivated the development of cell culture involving extracellular mechanostimuli, with the intent of identifying mechanotransduction mechanisms that influence cell phenotypes. Collagen I is a main extracellular matrix (ECM) component used to study mechanotransduction in three-dimensional (3D) cell culture. There are also models with interstitial fluid stress that have been mostly focusing on the migration of invasive cells. We argue that a major step for the culture of tumors is to integrate increased ECM stiffness and fluid movement characteristic of the TME. Mechanotransduction is based on the principles of tensegrity and dynamic reciprocity, which requires measuring not only biochemical changes, but also physical changes in cytoplasmic and nuclear compartments. Most techniques available for cellular rheology were developed for a 2D, flat cell culture world, hence hampering studies requiring proper cellular architecture that, itself, depends on 3D tissue organization. New and adapted measuring techniques for 3D cell culture will be worthwhile to study the apparent increase in physical plasticity of cancer cells with disease progression. Finally, evidence of the physical heterogeneity of the TME, in terms of ECM composition and stiffness and of fluid flow, calls for the investigation of its impact on the cellular heterogeneity proposed to control tumor phenotypes. Reproducing, measuring and controlling TME heterogeneity should stimulate collaborative efforts between biologists and engineers. Studying cancers in well-tuned 3D cell culture platforms is paramount to bring mechanomedicine into the realm of oncology.

Relación de los trastornos posturales del sistema estomatognático con las patologías de la columna lumbar, en pacientes adultos del servicio de fisioterapia y rehabilitación del Hospital Militar Central de las Fuerzas Armadas

El Sistema Estomatognático es uno de los sistemas más complejos del cuerpo humano, influye de manera concreta sobre otros sistemas respetando los principios de biotensegridad, ya que este sistema y su posición influye con el centro de gravedad al punto de que el Sistema Estomatognático lo relacionamos con patologías de la columna lumbar en pacientes adultos. El diseño de la investigación fue de tipo experimental, enfoque cuantitativo. El objetivo fue “analizar la relación de los trastornos posturales del Sistema estomatognático con las patologías de la columna lumbar en pacientes adultos en el año 2019”. La muestra formada 40 pacientes adultos de ambos sexos, comprendido entre 18 a 60 años, con patologías lumbares. La fuente primaria de donde se obtuvieron los datos es un software Al Posture Evaluation and Correction Sistem APECS, versión 1.84 evaluación completa en todos los planos más en flexión. Las fichas fueron codificadas por números correlativos para salvaguardar las características personales del paciente. Cada paciente le correspondió 18 fichas con diferentes características en total se analizó 720 fichas. Se observó la diferencia de promedios de cambios biomecánicos en el plano anterior con el promedio de mejoría de 0,9° en el grupo experimental vs al -0,2° en el grupo control en el plano posterior una mejoría de cambios de 1,3 en el grupo experimental vs el 0,2 del grupo control. En el plano lateral derecho y lateral izquierdo los cambios se presentaron en aumento la angulatura después del tratamiento lo que la diferencia de los promedios de antes y después arrojo datos negativos para el plano lateral derecho de -0,81° para el grupo experimental y -1,41° grupo control. El dolor mejoro en ambos grupos, sin embargo fue más significativo en el grupo experimental.

Reconfiguration of planar quadrilateral linkages utilizing the tensegrity principle

The development of reconfigurable planar four-bar linkages by applying the tensegrity principle is considered. Conventional quadrilateral linkages enable two operation modes differing in the kinematic behavior. However, a change between these states is not possible due to the geometric constraints. To enable a reconfiguration between the different modes one-sided limited nonholonomic constraints are introduced in this work. This issue is realized by applying ropes that cannot resist compression. However, to guarantee an appropriate load case in operation a prestress within the mechanism is required. Hence, the linkage is extended to a tensegrity-based mechanism. The structural dynamics are derived using the Lagrange formalism and the structural behavior is evaluated using numerical simulations. Furthermore, a prototype of an exemplary tensegrity-based mechanism is manufactured and experiments regarding the mechanical properties, in particular the reconfiguration, are performed. The results suggest the potential benefit of applying the tensegrity principle within conventional planar four-bar linkages.

Mechanical response of tensegrity dissipative devices incorporating shape memory alloys

To optimize the seismic performance prescribed by modern structural codes, buildings and infrastructures must provide adequate safety for design level earthquake excitations, with limited levels of damage. This paper deals with the computational modelling of a bracing system with tensegrity architecture, which operates as a lightweight mechanical amplifier of longitudinal displacements in the transverse direction, efficiently limiting the interstory drifts while dissipating energy. The proposed brace is based on a D-bar tensegrity structure with a rhomboidal shape comprising Shape-Memory Alloy (SMA) tendons. The SMA tendons can develop austenitic-martensitic (solid to solid) transformations, which enable them to amplify the signals into wide super elastic hysteresis, while subjected to mechanical cycles, comprising strains up to 6÷8%, with no residual deformations. The enhanced energy dissipation of the proposed SMA-D-bar (SMAD) braces are demonstrated through computational simulations of the response of braced frame to real earthquake events. The efficiency of the intended bracing to minimize the seismic impact of the served structure lays the foundation for the development of novel seismic energy dissipation systems integrating principles of tensegrity with superelasticity.

Trabecular architecture during the healing process of a tibial diaphysis defect

The adaptation of trabecular bone microstructure to mechanical loads has been intensively investigated. However, loading-unrelated aspects of trabecular architecture remain unclear. We used synchrotron radiation-based X-ray microtomography to study the 3D microarchitecture of newly formed trabecular tissue in a defect produced in the cortical region of the rat tibia diaphysis, in the absence (7, 14, and 21 days) or the presence (21 days) of carbonated hydroxyapatite/alginate (cHA) microspheres. This work provides the first evidence that the woven bone trabecular network, formed during the healing process, displays a well-organized 3D microarchitecture consisting of nodes with 3 (3-N), 4 (4-N) and 5 (5-N) connecting trabeculae, with a mean relative abundance of (3-N)/(4-N)/(5-N) = 66/24/7, for the analyzed periods. The measured inter-trabecular angles (ITA) distribution presented a Gaussian profile, with mean value at 115° for 3-N nodes, and 105° for 4-N nodes, close to the angles of idealized 3D regular structures (120° and 109.5°, respectively). Changes in the dispersion of ITA distribution suggested that a highly symmetric trabecular fabric organized under tensegrity principles is formed early during the bone healing process. Post-implantation, cHA disaggregated into multiple fragments (~20–400 μm), stimulating osteoconduction and bone growth toward the interior of the medullary cavity. The presence of biomaterials in bone defects affected the trabecular dimensions; however, it did not interfere with the formation of geometrical motifs with topological parameters similar to those found in the sham-defects. Statement of SignificanceThe trabecular bone microstructure enables the tissue to meet the necessary mechanical and functional demands. However, the process of trabecular microarchitecture formation during healing, in the absence or presence of a bone graft, is not yet well understood. This work demonstrated that, from the beginning of its formation in cortical bone defects, the woven-bone trabecular network is spatially organized according to the principle of tensegrity. This microarchitecture is comprised of highly symmetric geometric motifs and is an intrinsic characteristic of trabecular growth, regardless of hierarchical scale or mechanical stimulation. The addition of a biodegradable nanostructured calcium phosphate graft did not disrupt trabecular microarchitecture; however, graft biodegradation should be controlled to optimize the reproduction of intrinsic trabecular motifs throughout the defect.

Scoliosis induced by costotransversectomy in minipigs model.

Aim To validate surgical costotransversectomy as a technique for creating a scoliosis model in minipigs and to assess whether differences in approach (posterior medial approach, posterior paramedial approach and anterior approach by video-assisted thoracoscopy) lead to differences in the production of spinal deformity. Creation of disease models in experimental animals, specifically in minipigs, is controversial, as no appropriate technique has been reported. Methods Surgical costotransversectomy was performed in 11 minipigs using 3 different approaches: posterior medial approach (4 animals, group I), posterior paramedial approach (3 animals, group II) and anterior approach by videothoracoscopy (4 animals, group III). A conventional x-ray study was performed in the immediate postoperative period. Follow-up lasted for 4 months. Specimens were humanely killed according to current protocols, and a second x-ray study was performed. A deformation was measured using the Cobb angle and direct observation of the rotational component. Results Data from group I revealed a scoliosis deformation of 27º-41º (mean 34.5º) with a macroscopic rotational component. No deformity (<10º) or rotational component was observed in groups II and III. Only a posterior medial costotransversectomy produced a significant deformity in minipigs and established a valid model for studying scoliosis in these animals. Conclusion Only a posterior medial costotransversectomy produces a significant deformity in minipigs and establish a valid model for studying scoliosis in these animals. A tensegrity model would elucidate such results and harmonize disparate conclusions. Further investigation is needed to demonstrate the reliability of tensegrity principles for spinal biomechanics.

Synergistic control of a multi-segments vertebral column robot based on tensegrity for postural balance

ABSTRACTWe present a neuronal architecture to control a compliant robotic model of the human vertebral column for postural balance. The robotic structure is designed using the principle of tensegrity that ensures to be lightweight, auto-replicative with multi-degrees of freedom, flexible and also robust to perturbations. We model the central pattern generators of the spinal cords with a network of nonlinear Kuramoto oscillators coupled internally and externally to the structure and error-driven by a proportional derivative (PD) controller using an accelerometer for feedback. This coupling between the two controllers is original and we show it serves to generate controlled rhythmical patterns. We observe for certain coupling parameters some intervals of synchronization and of resonance of the neural units to the tensile structure to permit smooth control and balance. We show that the top-down PD control of the oscillators flexibly absorbs external shocks proportionally to the perturbation and converges to steady state behaviors. We discuss then about our neural architecture to model motor synergies for compliance control and also about tensegrity structures for soft robotics. The 3D printed model is provided as well as a movie at the addresshttps://sites.google.com/site/embodiedai/current-research/tensegrityrobots.

Effect of remote myofascial release on hamstring flexibility in asymptomatic individuals – A randomized clinical trial

BackgroundThe existence of continuity between fascia and muscles that may be anatomically distant from each other is emphasized in the tensegrity principle. Despite evidence from in vitro studies, there is a dearth of literature concerning the in vivo behavior of these connections. AimTo compare the effect of Static Stretching (SS) of hamstrings with remote Myofascial Release (MFR) (bilateral plantar fascia and suboccipital region) and a combination of SS and remote MFR on hamstring flexibility. The secondary aim of this study was to investigate the difference between therapist administered and self-administered interventions. DesignThree arm assessor-blinded Randomized Clinical Trial (RCT). ParticipantsFifty-eight asymptomatic participants (16 Males; Mean age 22.69 ± 2.65 years). MethodParticipants with tight hamstrings defined by a passive Knee Extension Angle (KEA) > 20° were included in the study and were assigned to one of the three groups. Group A (n = 19) was SS, group B (n = 20) was remote MFR, group C (n = 19) was a combination group who received both SS and remote MFR. Seven sessions of therapist administered intervention were delivered over a period of 10 days, which was followed by a 2-week self-administered home program. KEA and Sit and Reach Test (SRT) were used as outcomes and measurements were performed at baseline, end of the seventh session and after atwo-week follow-up. ResultsThe results demonstrated that hamstring flexibility improved in all three groups after therapist administered interventions (p < 0.05), whereas, group C demonstrated additional benefits. None of the groups showed a statistically significant (p > 0.05) change in the KEA with self-intervention. ConclusionThe findings of this study indicated that all three interventions were effective in improving hamstring flexibility in young asymptomatic individuals when performed by the therapist.

TENSOR: Integration of Tensegrity and Origami to Generate Hybrid Structural Morphologies

This research re-evaluated the relationship between origami and tensegrity through computational means. Objective of this study is to study how geometrical principles of origami and structural principles of tensegrity can be integrated together to generate hybrid structural system through digital investigation. Origami folding has potential of developing deployable, reconfigurable structural system, where materiality plays a major role in the design. These techniques are researched using algorithmic tools and mathematics to attend geometric precision and complexity. With the help of simulation, certain origami folds had potential to integrate with tensegrity modules, where geometry is stabilized by adding another parameter will generate hybrid structural system.

The effect of a single massage based on the tensegrity principle on postural stability in young women.

The aim of this study was to investigate the effects of normalized muscle tension via tensegrity-based massage on postural stability in a sample of female young adults. Nineteen females aged 21.8 ± 1.9years were recruited presenting abnormal tension at muscles adhering to any of the following structural sites: superior iliac spine, lateral sacropelvic surface, linea aspera at 1/2 of femur length, and superior nuchal line of the occiput. Balance and postural control were assessed during bipedal stance using a force platform in multiple conditions: hard surface or soft foam surface with the head in either a neutral posture or tilted backward. Baseline and 3-min and 15-min post-treatment measures were collected while barefoot and eyes closed. Main outcomes measures included center of pressure variability, range, radius, and velocity in the anteroposterior (AP) mediolateral (ML) dimensions. In the solid surface with neutral head posture condition only AP COP measures decreased significantly (p< 0.05). In the soft surface condition, significant differences were observed in the AP and ML dimensions among most measures (p< 0.05). A single application of tensegrity-based massage positively influenced postural control in young adult females, particularly in the AP direction.

Shape and Stress Modification of a Chosen Tensegrity System

Already for more than half a century, tensegrities have noticed a growing researchers’ interest in many fields of science. Despite this relatively long time of a tensegrity idea's existence, structures using entirely or partially a tensegrity principle (i.e. predefined compression members surrounded by a network of predefined tension members with changeless orientation of normal forces during loading) are even at the present time progressive in comparison to common rigid as well as flexible structures. Furthermore, connection between tensegrity systems and information technology is interesting and brings a new view on creation and operation of nowadays conventional structures. By means of active members (actuators) the tensegrity system is able to change its shape and resulting state of stress. Such geometrical and stress modifications are mandatory in order to meet service and ultimate state criteria. The article deals with searching for a convenient shape and stress modification of a chosen tensegrity system in accordance with defined criteria. Obtained results showed to be satisfactory with regard to demanded modification.

The Performance of Half-Cuboctahedron Grid Tensegrity Systems in Roof Structures

Background/Objectives: Sustainability in the use of material and economy are the watchwords of the modern engineering fraternity. Many structural systems have been evolved for this purpose. At present, the qualities of the tensegrity structures, which make the technology attractive for human use, are their resilience and ability to use the material in a very economical way. Thus, the construction of the structures using tensegrity principle will make them highly resilient and reasonably economical at the same time. Methods: Though a lot of research has been carried out on the behaviour of tensegrity systems, the area requires further research for a complete understanding. Hence, this project is aimed at analysis of a tensegrity based roof structure. The prototype module used is half-cuboctahedron. Findings: First, a single module measuring 1 m x 1 m in size, is modelled and analysed using an FEM based software. The investigations are then extended to a 2 x 2 grid, measuring 2 m x 2 m in size. The behavior of the grid is studied under the application of external loads varying the prestressing forces on the members. Later, a 4 x 4 grid, measuring 4 m x 4 m in size and an 8 x 8 grid, measuring 8 m x 8 m in size are modelled and analysed based on the 2 x 2 grid system. From the analysis, it is found that the displacements of the system satisfy the permissible limits as per previous research values. The member forces have also been analysed. Applications/Improvements: The performance of the half-cuboctahedron tensegrity grid structure proves to be more suitable for larger span structures.