Computational Design
Biomimetics- Natural System Mimosa Pudica
Namraota Jain-PID20215 Sanajana Sreedhar- PID20308
CEPT University|Master of Interior Design
Abstract
This project focuses on the structure and behavior of Mimosa Pudica as a natural system and its possible application in architectural design. Mimosa pudica belongs to family of Leguminosae. It is commonly knows as ‘touch me not’ plant or ‘sensitive plant’. It is commonly found in tropical America, Australia and India, heavily armed with recurved thorns and having sensitive soft grey green leaflets. Once any part of surface like petiole or leaflet is stimulated, the leaves fold.1 The main aim of this project, which is based on Mimosa Pudica, is to achieve a double-curved system in which movement is transferred from one point to another when force is applied at any one point. To achieve this movement in a doubly curved surface, experiments using scissor mechanism are carried.
CEPT University|Master of Interior Design
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Table of contents
1. Abstract 2. Introduction 2.1 The Natural System- Mimosa Pudica 2.2 The Developed System 3. Experiments 3.1. Experiment 1 Experiment 1a Experiment 1b Experiment 1c 3.2. Experiment 2 Experiment 2a Experiment 2b 3.3. Experiment 3 Experiment 3a 3.4. Experiment 4 Experiment 4a Experiment 4b 3.5. Experiment 5 Experiment 5a Experiment 5b Experiment 5c 3.6. Experiment 6 Experiment 6a Experiment 6b Experiment 6c Experiment 6d 3.7. Experiment 7 Experiment 7a Experiment 7b 3.8. Experiment 8 3.9. Experiment 9 Experiment 9a Experiment 9b Experiment 9c Experiment 9d 3.10. Experiment 10 4. Conclusion 5. References
CEPT University|Master of Interior Design
2. Introduction Natural systems are effective in producing material and energy efficient solutions in response to external stimuli and environment. The intention of the studio is to decipher the logic embedded within these systems of mathematics, geometry, hierarchical logic, material properties and jointing mechanisms to develop interior architectural systems. In order to develop a material system, concepts of material based mechanics, mathematics and science are combined By learning from the functional principles of natural forms. Material system is a system resulting out of the properties inherent to the material or a manipulation of those, inorder to extract maximum desired performance v/s minimum materialusage. In this case, Mimosa Pudica as a natural system will be studied to develop a Material System by performing experiments. Various stages of experimenting includes developing performance active models, clear diagramming, prototyping, detailing and joineries, physical and digital fabrication processes. The results obtained will be used to explore the possibility of a material system based on the natural system.
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2.1 The Natural SystemMimosa Pudica Unlike animals, plants are often regarded as immotile organisms, as they do not normally make movements that can be easily observed by humans. However, in nature, plants can slowly displace their bodies in response to various stimuli. Such types of slow movements (minutes to hours) are widely seen in plants as they adapt to various environmental pressures. For example, in response to mechanical stimulation, the sensitive leguminous plant Mimosa Pudica quickly folds its leaves.
External stimulus Rapid movement
Reversible Slow recovery Fig 1: Factors affecting the movement in plant
When a leaf of M. pudica is mechanically stimulated (e.g., touched by hand), it drops and leaflets are folded upward. Such rapid movements are only possible due to the existence of the pulvini, found at the base of leaflet, rachilla, and petiole. Of the three types of pulvini found in M. pudica, the primary and tertiary pulvini are more sensitive to mechanical stimuli than the secondary pulvinus. When M. pudica is stimulated, it generates a stimulus-induced signal propagating toward distant organs. Early studies examining this phenomenon monitored the pulvinar movement as a visible indicator of signal transmission. Sudden turgor loss in the pulvinus caused by water redistribution is the driving force behind rapid movements in plants.2
Leaves collapse due to Loss of Turgor Pressure under Stimulus
Pulvinus
Factors affecting movement in M. pudica1. Touch 2. Sunlight 3. Temperature
Fig 2: Mimosa Pudica under stimulus
before stimulus low pressure
after stimulus high pressure
high pressure
low pressure
4. Vibration This project attempts to understand and analyze the movement in M. pudica due to touch. The findings are used to develop a material system in which movement is transferred from one point to another.
CEPT University|Master of Interior Design
Fig3: Pressure difference inside the pulvinus
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2.2 The Developed SystemDeployable Structures Deployable scissor structures can quickly transform between different configurations, making them particularly fit for exploring the movement mechanism of M. pudica. Their ability to deploy typically comes along with a high design complexity and a limited freedom of shape. A deployable scissor grid can be considered as a kinematic linkage of scissor units, also known as pantographs or scissor-like element. A scissor unit consists of a pair of bars crosswise interconnected by a revolute joint, allowing a relative rotation about an axis normal to the unit plane (i.e. the plane containing the scissor bars). The imaginary lines running through the upper and lower end point at both sides of the unit are called the unit lines. Depending on how these lines vary during deployment, different types of scissor units can be distinguished (Fig. 4), each offering a unique range of geometric possibilities and kinematic behaviour. The kinematic behaviour of a scissor grid depends on the type of scissor unit used, the geometric constraints that have been applied and the configuration in which the units are assembled.3 This behaviour is described by the scissor grid’s geometric compatibility during the two outer deployment stages (e.g. the expanded, functional stage and the compact, stowed configuration) and the transition stage. A scissor grid is geometrically compatible when all its members fit together without deformations. The scissor units considered in this project consist of straight bars and curved bars that have intersecting unit lines (Fig. 4b). This is done to achieve a global double-curved deployable system.
CEPT University|Master of Interior Design
a: Parallel unit lines
b: Intersecting unit lines
Fig4: Scissor mechanism
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3. Experiments Aim- To observe deflection from mimimum to maximum in terms of height and span of curvature by varying point to point connection The experiments use sticks of MDF joined together using hinge joint. Explorations are done using linear, curved and filleted sticks of varying lengths to achieve a double-curved geometry. Two of the hinge joints are kept fixed and a third joint is shiftedto achieve curved deployable geometry that moves on applying force on one point. Once this is achived, the next step involves joining the modules in multiple axes to achieve similar result. Techniques such as joining alternate modules, mirroring of modules, aggregation etc are used to develop a material system. Initially, off-centered points in one axis resulting in a single-curved system. In the next step, another axes was used to join the sticks together which gave a double-curved system. Finally, the joinery pattern obtained was replicated in the third axis by aggregating. As a result, a double-surved anticlastic deployable system was obtained.
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3.1. Experiment 1 ParametersConstant: - length of sticks: 10x - width of sticks: x - no. of sticks: 6
- distance between two points: x - Two points of connection: 1-1. 9-9
Variables: - 2nd point of connection
Module
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Experiment 1a Variables: - 2nd point of connection: 5-5
Variable Pt 5
Input Diagram
a) Close
b) Semi open
c) Open
Output: - Length (closed)= 5.5x - Length (open)= 26.5x - Geometry is linear - No curvature is formed
CEPT University|Master of Interior Design
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Experiment 1b Variables: - 2nd point of connection: 6-6 Variable Pt 6
Input Diagram
b) Semi open
b) Semi open
height (h)
height (h)
a) Closed
c) Open
span (s)
c) Open
height (h)
a) Closed
span (s)
span (s)
Output: a) h=10x; s=9x b) h= 9.5x; s=18x c) h=14x; s=14x
CEPT University|Master of Interior Design
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Experiment 1c Variables: - 2nd point of connection: 6-6 Variable Pt 7
Input Diagram
b) Semi open
b) Semi open
height (h)
height (h)
a) Closed
c) Open
span (s)
c) Open
height (h)
a) Closed
span (s)
span (s)
Output: a) h=9.5x; s=15.5x b) h= 10.5x; s=20x c) h=15.5x; s=10x
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3.2. Experiment 2 ParametersConstant: - length of sticks: 10x - width of sticks: x - no. of sticks: 6
- distance between two points: x - Two points of connection: 2-2. 8-8
Variables: - 2nd point of connection
Module
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Experiment 2a Variables: - 2nd point of connection: 5-5 Variable Pt 5
Input Diagram
a) Closed
b) Semi open
c) Open
Output: - Length (closed)= 6x - Length (open)= 22x - Geometry is linear - No curvature is formed
CEPT University|Master of Interior Design
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Experiment 2b Variables: - 2nd point of connection: 6-6 Variable Pt 6
Input Diagram
a) Closed
b) Open
height (h)
b) Open
height (h)
a) Closed
span (s)
span (s)
Output: a) h=10x; s=13x b) h= 10x; s=18x
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3.3. Experiment 3
ParametersConstant: - length of sticks: 10x - width of sticks: x - no. of sticks: 8
- distance between two points: x - Two points of connection: 1-1, 9-9
Variables: - Two points of connection
Module
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Experiment 3a Variable Pt 4
Variables: - 2nd point of connection: 5-5
Variable Pt 6
Input Diagram
a) Closed
b) Semi open
c) Open
Output: - Length (closed)= 8x - Length (open)= 36x - Geometry is linear - No curvature is formed
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3.4. Experiment 4 ParametersConstant: - length of sticks: 10x - width of sticks: x - no. of sticks: 12
- distance between two points: x - Two points of connection: 1-1, 9-9
Variables: - Two points of connection
Module
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Experiment 4a Variables: - 2nd point of connection: 4-4, 6-6
Variable Pt 6 Variable Pt 4
Input Diagram
a) Closed
b) Semi open
span (s)
c) Open
height (h)
b) Semi open
height (h)
height (h)
a) Closed
c) Open
span (s)
span (s)
Output: a) h=10x; s=11x b) h= 14x; s=27.5x c) h=13.7x; s=27x CEPT University|Master of Interior Design
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Experiment 4b Variable Pt 7
Variables: - 2nd point of connection: 3-3, 7-7 Variable Pt 3
Input Diagram
span (s)
b) Semi open
height (h)
height (h)
a) Closed
b) Semi open
span (s)
c) Open
c) Open
height (h)
a) Closed
span (s)
Output: a) h=10x; s=11x b) h= 14x; s=27.5x c) h=13.7x; s=22.5x
CEPT University|Master of Interior Design
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3.5. Experiment 5 ParametersConstant: - length of sticks: 10x - width of sticks: x
- distance between two points: x - Points of connection
Variables: - No. of connection between Module 1 and Module 2
Module 1 in X-axis
Connector
Module 2 in Y-axis CEPT University|Master of Interior Design
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Experiment 5a Variables: - Module in y-axis connected to the ends
Plan showing connections a) Closed
b) Open
b) Open
height (h)
height (h)
a) Closed
span (s)
span (s)
Outputa) h=8x; s=14x b) h=12.5x; s=32.5x CEPT University|Master of Interior Design
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Experiment 5b Variables: - Module in y-axis connected intermediately
Plan showing connections
a) Closed
height (h)
b) Open
span (s)
a) close condition
Outputa) h=15x; s=28x b) h=14x; s=40x
b) open condition CEPT University|Master of Interior Design
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Experiment 5c Variables: - Module in y-axis connected at ends as well as intermediately
Plan showing connections a) Closed
b) Open
X- axis
Y- axis
X- axis
Y- axis
Y- axis
height (h)
height (h)
X- axis
a) close condition
span (s)
span (s)
Outputa) x-axis h=10.8x; s=36x b) x- axis h=9.8x; s=35.5x
a) y-axis h=15x; s=17.5x b) y- axis h=13x; s=21.5x
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b) open condition
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3.6. Experiment 6 ParametersConstant: - length of sticks: 10x - width of sticks: x
- distance between two points: x - Points of connection
Variables: - Axis of joinery - Connector
X
10
X
Module
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Connector-variable
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Experiment 6a
Input Diagram
a) Closed
b) Open
Output: -Length (closed) - 15.5x -Length (open) - 10x - Geometry is linear -No curvature is formed - Geometry is linear - No curvature is formed
CEPT University|Master of Interior Design
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Experiment 6b
Input Diagram
a) Closed
b) Open
Output: -Length (closed) - 13.5x -Length (open) - 15.5x - Geometry is linear -No curvature is formed - Geometry is linear - No curvature is formed
CEPT University|Master of Interior Design
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Experiment 6c a) Closed
Input Diagram
b) Open
Output: -Length (closed) - 30.7x -Length (open) - 28.3x - Geometry is linear -No curvature is formed - Geometry is linear - No curvature is formed
CEPT University|Master of Interior Design
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Experiment 6d
Variable Pt 4 Variable Pt 6
Input Diagram
a) Closed
b) Open
height (h)
height (h)
a) Closed
b) Open
span (s)
span (s)
Output: a) h=16.8x; s=53x b) h= 17x; s=69.2x
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3.7. Experiment 7 ParametersConstant: - length of sticks: 10x - width of sticks: x
- distance between two points: x - Two points of connection: 1-1, 9-9
Variables: - Third point of connection
Module
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Experiment 7a Variables: - 3rd point of connection: 5-5
Variable Pt 5
Input Diagram
b) Semi open
span (s)
span (s)
c) Open
c) Open
height (h)
a) Closed
height (h)
b) Semi open
height (h)
a) Closed
span (s)
Output: a) h=8.8x; s=8.5x b) h= 7.6x; s=19.4x c) h= 5.5x; s=21x
CEPT University|Master of Interior Design
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Experiment 7b Variables: - Point of connection: 4-4, 6-6
Variable Pt 4 Variable Pt 6
Input Diagram
height (h)
a) Closed
span (s)
b) Semi open
span (s)
c) Open
c) Open
height (h)
b) Semi open
height (h)
a) Closed
span (s)
Output: a) h=8.7x; s=22.4x b) h= 15x; s=34.1x c) h= 24x; s=23.7x
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3.8. Experiment 8
10
Pt 1 Pt 2
ParametersConstant: - length of sticks: 10x - width of sticks: x
Pt 3
- distance between two points: x - no. of sticks: 6
Pt 4 Pt 5 Pt 6
Variables: - connection
Pt 7 Pt 8 Pt 9
Module
X
10
X
Connector
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Constant Pt 01
Constant Pt 1
Variable Pt
Variable Pt
Constant Pt 09
Constant Pt 9
Input Diagram b) Open
height (h)
a) Closed
Output: a) h=15.5x; s=44x b) h= 31.5x; s=76.5x span (s) a) close condition b) open condition
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3.9. Experiment 9
ParametersConstant: - length of sticks: 10x - width of sticks: x
- distance between two points: x - no. of sticks: 6
Variables: - connection of Module 2 at the centre.
Module 1- Constant
X
10
X
Module 2- Variable
CEPT University|Master of Interior Design
Connector
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Experiment 9a
Input Diagram
height (h)
a) Closed
b) Open
Output: a) h=20.1x; s=50.2x b) h= 22x; s=63.4x span (s) a) close condition b) open condition
CEPT University|Master of Interior Design
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Experiment 9b
Input Diagram
height (h)
a) Closed
b) Open
span (s) a) close condition b) open condition
Output: a) h=14.5x; s=47.3x b) h= 18x; s=68.3x
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Experiment 9c
Input Diagram
height (h)
a) Closed
b) Open
a) close condition
span (s)
b) open condition
Output: a) h=17.3x; s=49.3x b) h= 17.5x; s=69.3x
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Experiment 9d
Input Diagram
height (h)
a) Closed
b) Open
a) close condition
span (s)
b) open condition
Output: a) h=15x; s=47.7x b) h= 15.2x; s=68.2x
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3.10. Experiment 10
Input diagram
X- axis
Y- axis
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height (h)
Curve along x-axis
span (s)
height (h)
Curve along y-axis
span (s) a) close condition b) open condition
Outputalong x-axis open: h= 40.4x, s=100.5x close: h=33.6, s= 80.2x CEPT University|Master of Interior Design
along y-axis open: h= 28.5x, s=86.8x close: h=27.7, s= 73.5x 40
4. Conclusion The experimentations are an exploration of the stimulus movement of Mimosa Pudica plant. To achieve this, common deployable structures using scissor-hinge structural mechanisms were investigated. During this investigation, geometric and kinematic principles of these structures were examined and their shortcomings with respect to form flexibility were exposed. The proposed scissor-hinge structure has both 2D and 3D versions. 2D version of the structure can constitute various curvilinear geometries. The 3D version presents remarkable form flexibility from curvilinear to double-curved shapes. The material system developed can achieve remarkable transformations. A deployable doubly curved system was obtained in most of the experiments. It was also observed that magnitude of movement increases as the distance between connection point and the module increases. The explorations can contribute to the field of Architecture, Interior and Technology. Where buildings are expected to be smart and responsive, such system explorations can fulfill those expectations.
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5. Bibliography 1. Volkov, A. G., & Markin, V. S. (2014). Active and Passive Electrical Signaling in Plants. 2. Aduldejcharas, R. (2015-16). Biomimicry Mimosa Pudica. AA London. 3. Bhushan, B. (2009, April 28). Biomimetics: lessons from nature–an overview. Retrieved from https://royalsocietypublishing.org/: https://royalsocietypublishing.org/doi/10.1098/rsta.2009.0011 4. Hagihara, T., & Toyota, M. (2020). Mechanical Signaling in the Sensitive Plant. 5. Kinematic Analysis of Deployable Scissor Structures. (1999). International Journal of Space Structrures. 6. Roovers, K. (2017, August 15). Deployable scissor grids consisting of translational units. Retrieved from https://www.sciencedirect.com/: https://www.sciencedirect.com/science/article/pii/S0020768317302184 7. von, V., Akgün, Y., & Türkei, E. (2010). A NOVEL TRANSFORMATION MODEL FOR DEPLOYABLE SCISSOR-HINGE STRUCTURE. Universität Stuttgart.
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