Concepts for Power and Energy Analysis in Nastic Structures

Giurgiutiu, Victor; Matthews, Luke; Leo, Donald J.; Sundaresan, Vishnu-Baba

doi:10.1115/imece2005-82786

Cited by 5 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence FMC actuators can be designed to twist or provide greater axial force than a PAM actuator. (184)(185)(186)(187)(188)(189) In the papers by Shan et al (188,189) an analytical model is presented that is validated by experimental data. The results show that the modulus of a single FMC tube is a function of the fibre braid angle and that the demarcation angle between contraction and extension angle increases with the moduli ratio E 1 /E 2 and converges to around 55° when E 1 /E 2 > 100.…”

Section: Magnetic Shape Memory Materialsmentioning

confidence: 99%

Morphing skins

et al. 2008

View full text Add to dashboard Cite

A review of morphing concepts with a strong focus on morphing skins is presented. Morphing technology on aircraft has found increased interest over the last decade because it is likely to enhance performance and efficiency over a wider range of flight conditions. For example, a radical change in configuration, i.e. wing geometry in flight may improve overall flight performance when cruise and dash are important considerations. Although many morphing aircraft concepts have been elaborated only a few deal with the problems relating to a smooth and continuous cover that simultaneously deforms and carries loads. It is found that anisotropic and variable stiffness structures offer potential for shape change and small area increase on aircraft wings. Concepts herein focus on those structures where primary loads are transmitted in the spanwise direction and a morphing function is achieved via chordwise flexibility. To meet desirable shape changes, stiffnesses can either be tailored or actively controlled to guarantee flexibility in the chordwise (or spanwise) direction with tailored actuation forces. Hence, corrugated structures, segmented structures, reinforced elastomers or flexible matrix composite tubes embedded in a low modulus membrane are all possible structures for morphing skins. For large wing area changes a particularly attractive solution could adopt deployable structures as no internal stresses are generated when their surface area is increased.

show abstract

Section: Magnetic Shape Memory Materialsmentioning

confidence: 99%

Morphing skins

et al. 2008

View full text Add to dashboard Cite

show abstract

“…3 Research is also currently underway to examine the introduction of the enzyme ATPase to reverse ATP hydrolysis, making the reaction renewable. Future research will also involve, among other things, taking into consideration the effect of atmospheric temperature change and blocking forces on the nastic energy system.…”

Section: Discussionmentioning

confidence: 99%

“…3 In this article, the volume increment from actuation is considered without any outside forces, so ⌬V load can be evaluated as zero. The fluid compressibility under high fluid pressure forces is dependent on the volume of the cylinder, bulk modulus of the fluid, and the applied pressure.…”

Section: Mechanical Actuationmentioning

confidence: 99%

“…The motor cells cause a change in confirmation of the leaves or stem from external stimulus like sunlight or a prey as in the case of insectivorous plants. 1,3 Nastic motion in plants results from osmotic pressure regulation in cellular compartments causing bulk expansion in the tissue. A nonuniform volume change throughout the tissue results in different configurations of the tissue.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bioenergetics and mechanical actuation analysis with membrane transport experiments for use in biomimetic nastic structures

et al. 2006

Self Cite

View full text Add to dashboard Cite

Nastic structures are synthetic constructs capable of controllable deformation and shape change similar to plant motility, designed to imitate the biological process of nastic movement found in plants. This paper considers the mechanics and bioenergetics of a prototype nastic structure system consisting of an array of cylindrical microhydraulic actuators embedded in a polymeric plate. Non-uniform expansion/contraction of the actuators in the array may yield an overall shape change resulting in structural morphing. Actuator expansion/contraction is achieved through pressure changes produced by active transport across a bilayer membrane. The active transport process relies on ion-channel proteins that pump sucrose and water molecules across a plasma membrane against the pressure gradient. The energy required by this process is supplied by the hydrolysis of adenosine triphosphate. After reviewing the biochemistry and bioenergetics of the active transport process, the paper presents an analysis of the microhydraulic actuator mechanics predicting the resulting displacement and output energy. Experimental demonstration of fluid transport through a protein transporter follows this discussion. The bilayer membrane is formed from 1-Palmitoyl-2-Oleoyl-sn-Glycero-3-[Phospho-L-Serine] (Sodium Salt), 1-Palmitoyl-2-Oleoyl-sn-Glycero- 3-Phosphoethanolamine lipids to support the AtSUT4 H+-sucrose cotransporter.

show abstract

“…The possibility of constructing a smart material composed of hydraulic microactuators that imitate nastic motor cells and use the same biological energy and power sources has been investigated in ref. [1] [2]. The biological energy for nastic movement is supplied by adenosine triphosphate (ATP) hydrolysis and used by SUT-4 active transport proteins to pump water into the cell, increasing osmotic pressure and causing the cell to swell.…”

Section: Introductionmentioning

confidence: 99%

Modeling actuation forces and strains in nastic structures

Matthews

Giurgiutiu

2006

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

Nastic structures are capable of three dimensional shape change using biological principles borrowed from plant motion. The plant motor cells increase or decrease in size through a change in osmotic pressure. When nonuniform cell swelling occurs, it causes the plant tissue to warp and change shape, resulting it net movement, known as nastic motion, which is the same phenomena that causes plants to angle their broad leaf and flower surfaces to face light sources.The nastic structures considered in this paper are composed of a bilayer of microactuator arrays with a fluid reservoir in between the two layers. The actuators are housed in a thin plate and expand when water from the fluid reservoir is pumped into the actuation chamber through a phospholipid bilayer with embedded active transport proteins, which move the water from the low pressure fluid reservoir into a high pressure actuation chamber. Increasing water pressure inside the actuator causes lateral expansion and axial bulging, and the non-uniform net volume change of actuators throughout the nastic structure results in twisting or bending shape change. Modifying the actuation displacement allows controlled volume change. This paper presents an analytical model of the driving and blocking forces involved in actuation, as well as stress and strain that occurs due to the pressure changes. Actuation is driven by increasing osmotic pressure, and blocking forces are taken into consideration to plan actuator response so that outside forces do not counteract the displacement of actuation. Nastic structures are designed with use in unmanned aerial vehicles in mind, so blocking forces are modeled to be similar to in-flight conditions. Stress in the system is modeled so that any residual strain or lasting deformation can be determined, as well as a lifespan before failure from repeated actuation. The long-term aim of our work is to determine the power and energy efficiency of nastic structures actuation mechanism.

show abstract

Concepts for Power and Energy Analysis in Nastic Structures

Cited by 5 publications

References 2 publications

Morphing skins

Morphing skins

Bioenergetics and mechanical actuation analysis with membrane transport experiments for use in biomimetic nastic structures

Modeling actuation forces and strains in nastic structures

Contact Info

Product

Resources

About