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+FABRICATION_DESIGN DEVELOPMENT From our initial prototype we identified some key areas in which to improve upon our prototype:

1 DIFFERENT SIZED SPIKES that could be used to accentuate the effect of the personal space boundary.

2 The USE OF TENSIONING CABLES attached to each vertex of the second skin which

could act to exemplify the effect of crawling into a ball and establish a common point to which movement could be focused by attaching the tensioning cables at the same point.

3 A more RIGID MATERIAL that would more effectively stand against an invasion of

personal space. A specific area where this could be implemented would be along the long structural members, which could justify a change of material.


Attachment of slender spikes

The first task involved the smallest change of the design as it was simply an exaggeration of the effect. However, since the design involved triangles extending in both directions, we needed to consider an option which could only extend the length of the spikes and not their overall size. If the overall size was increased, this would infringe upon the mechanism, as shown on the next page. We solved this issue by attaching a long slender spike onto the existing spike, creating a longer and accentuated movement, as shown on the next page. By adding to the existing spikes in this way the movement of adjacent spikes were not blocked.


Option 1: The second modification we made to our initial prototype was the use of tensioning cables to greater capture the movement of crawling into a ball. By placing cables at the point of each vertex and attaching them to a common point, the movement could create a greater force upon the prototype and stretch the spikes further, to establish a greater boundary. Problem: To accomplish this we initially used copper wire, however this proved to be too rigid and did not adequately fit the body. The use of this material therefore did not accentuate the effect of the movement, but rather diminished it since it did not tightly hug the body.

Option 2: As a second option, we used a more flexible material: string. This proved to hug the body much more closely and achieved the intended effect of exaggerating the effect of the movement.


+FABRICATION_DESIGN DEVELOPMENT To accompany this addition we also added a way in which to attach the prototype to the body. For this we used a similarly flexible material: plastic. The use of Velcro and plastic in this instance allowed for a very accommodative and flexible prototype. The Velcro could be adjusted according to the particular user and in this case added to the effect of the tensioning cables since the Velcro could be fastened tightly around the body.

Velcro Attachment Method

Attachment of tensioning string to key vertices

These additions were successful in exaggerating the motion, the spikes deployed much easier and with much less movement. However, from this we realised the weakness of the material. The added force placed on the prototype from the tensioning string and attachment method caused parts of the prototype to rip under the force as it was not adequately strong enough to deal with the stress.



Building upon our prototype testing, we established NEW and functioning second skin: 1. 2.

AREAS OF FOCUS to make it a more successful

Discuss alternative ways in which the spikes could be deployed without damaging the prototype Experiment with different materials which could produce a stronger and more durable prototype.

The first of these proved to be far more difficult than initially anticipated. We decided to change the way the movement affected the deployment of spikes by changing the point of index from a horizontal plane to a vertical plane, that is, changing the movement from the expansion across the back to the expansion along the back. This change meant that there is a greater change in motion, since there is only so much your back expands across, whilst the action of crawling up in a ball dramatically changes the vertical plane of the back. However, changing the way movement along the back affected the spikes proved to be very difficult. Rather than pulling horizontally on the prototype, this new method was pulling vertically. We hence had to adopt an inverse trigger. This changed our deployment mechanism from a pulling motion to a pushing one. For inspiration we focused on pop-up books, which adopted a similar mechanism.



Resolving the material choice also proved to have some problems. Our first experiment was the use of plywood as the key structural members of the prototype as shown on the right. This way we could still achieve the flexibility needed in the spikes by using paper, but provide some strength and stability to the prototype. The plywood however, was too stiff and when the user crawled up into a ball, the plywood would not bend with the arch of the back and was in great risk of snapping. To resolve this we switched to a lighter, thinner plywood which provided greater flexibility but also a degree of stability and strength. This new structural base was far more successful in dealing with the applied force and was able to bend with the curvature of the back to make the second skin far more fitting to the body.

Several adjustments were also brainstormed and considered in relation to the visual impact of the prototype: - A change of shape from a diamond to a V-shaped prototype which would more effectively cover the back. - The use of plywood strips at the bottom and top of the back as a method of attachment to the body - The use of a clasp over the shoulder of the user which could be used as a method of attachment to the body - Lastly, the use of a clasp mechanism as a means of attachment over the shoulder was deemed to be ineffective. The clasp would not be able to hold the prototype to the body without the accompanying use of string to connect the bottom half to the clasp. For this reason, the use of string was deemed to be a simpler and effective method of attaching the prototype to the user as demonstrated in the previous prototype. In this case, the structural members were constructed of a stronger more durable material and more successful in dealing with the applied force.



Each of these proved to be unsuccessful as they impinged on the mechanism of the prototype: - Changing the shape from a diamond structure altered the way in which the lattice functioned. By having the V-shape the bottom of the prototype only had one point of contact which placed too much stress on the prototype and began to warp the mechanism. - The use of plywood strips as a method of attachment constricted the movement of the lattice. By connecting the strips with the bottom and top vertices as shown below, these members were unable to move and consequently the spikes were unable to deploy. As a result of the pulling motion the prototype narrows in size, as the lattice moves throughout the design. However, having the top and bottom members connected to a fixed point meant the prototype was unresponsive to the movement and rigid.

Module 3 monicasutisna 614340  
Module 3 monicasutisna 614340