The interactive Photoskin Wall can be configured in two ways: completely Analog or using Firefly.
In the Analog configuration, the wall responds directly to sensor data with one mode of behavior. An Arduino, Firefly and computer are not required. The wall just needs a power source such as batteries. The pores are organized into quads to minimize hardware. Click Read More to view drawings of the Analog configuration.
In the Firefly configuration, sensor data is collected and stored via Arduino and Firefly. The data is then processed and interpreted according to the various modes of behavior explored in the Grasshopper Behavior Sketches. The pores are organized into quads. Four quads relay information to one Arduino.
For both the Analog and Firefly configurations wires are embedded in the latex skin as shown in the drawing below.
Chalk guidelines were drawn on the latex skin to reflect the assembly frame location. Additional latex was dabbed where the latex would be attached to the plexiglass. Newly added latex forms a strong bond with existing latex when dry. Monofilament was threaded through the latex and then through the hole in the lever base and tied tight.
The “skin” of the Photoskin Wall was built up in layers using liquid latex. Latex was painted on a clean surface to the desired size. Liquid latex is milky white when wet and dries to a translucent beige. The first layer was allowed to dry for about 1 hour before a second layer was applied. This process was repeated several times to get the desired thickness for the skin. The initial muscle wire experiments helped determine the appropriate amount of layers. Since the skin also serves as a return weight for the muscle wire mechanism, the thickness of the latex affects the movement in the wall. If the skin is too thin, there will not be enough force returning the muscle wire to its original length when cooled. If the skin is too thick it will be too stiff to move. The final skin was built up in 5 layers.
The plexiglass component assembly of the Photoskin Wall is flexible enough to wrap around various curvatures or to deflect when force is applied. Furthermore, although components are securely linked, there is some latitude for movement in various directions. The following video demonstrates this flexibility and movement in the assembly.
Since plexiglass is a relatively brittle material, a flexible and forgiving structure is desirable to prevent plexiglass from snapping or cracking when forces are applied. It also provides an opportunity for unexpected movement in the wall, As pores open and close, the wall itself could buckle, twitch or weave as numerous minute forces act on it.
Monofilament fishing line is threaded through tiny precut holes at the tip of the lever base as shown graphically in the image below. Tension in the monofilament can be adjusted to achieve the desired shape and stiffness in the structure of the Photoskin Wall.
The interlocking plexiglass components of the Photoskin Wall are easily assembled by hand and further secured with monofilament. Here is a quick video demonstrating the assembly process.
Below are all the plexiglass components of the Photoskin wall.
These components were cut using a laser cutter.
Based on the results of the muscle wire experiments I revised the lever mechanism to maximize the amount of movement in the latex skin. Firstly, I increased the lever length, which meant increasing the depth of base. I had to be careful not to increase the length to much however, since increasing the length requires more force to move the lever. Since its difficult to measure exactly how much force the muscle wire is actually exerting, this is pretty much a trial and error process. This is why I added a few additional holes to the lever to allow for a little adjustability in the length. I also carved out some of the excess material in the base to lighten the overall wall assembly. I added a few other interlocking components that facilitate the connection between the lever base and the frame and provide a place for the latex to be connected. This allows for easy assembly by hand with just a little monofilament to secure the structure. Finally, I added a hole at the top of the base for monofilament to be thread through to create a triangulated tension that will prevent the buckling that was observed in the muscle wire experiments.
Summary of changes:
increased lever length to increase movement in latex
added additional holes in lever for adjustability of length
increased base depth to accommodate increased lever length
carved out excess material in the lever base to reduce overall weight
added interlocking components for easy connection between base and frame
added component onto which latex will be attached
added hole at top of base for monofilament to be thread through to create a triangulated tension that will prevent the buckling
These revised components will be cut out of plexiglass using a laser cutter.
Method of Interpretation:
In Study 3, incoming sensor data is processed and implemented in the same way as in Study 2 with one exception; a dominant sensor override condition is also included. This means that if any one sensor deviates from the average of the twelve sensors by 30% or more, then the aperture of all pods reacts to that one overriding sensor value, ignoring data from the other sensors. This reaction dissipates with each pod’s distance from the overriding sensor.
As long as incoming data from all twelve sensors is within 30% of the average value of all sensors, the relationship between pods and sensors is the same as in Study 2. However, if the value of one sensor falls above or below 30% of the average sensor value then all pods respond to that particular sensor, disconnecting their relationship with all other sensors. However, the pods are still linked to each other by extension since their position relative to each other effects the magnitude of their response to the overriding sensor.
For the most part, the response in the wall is similar to that of Study 2. The difference however is evident when one sensor is cast in shadow, such as when a person stands close to the wall or even reaches out with their hand, casting a primary shadow on one sensor. All pores in the wall react to this human activity, repositioning their aperture relative to the source of change. Therefore, based on the resulting behavior, you could say that this wall gives importance to human proximity.
Potential for Implementation:
This type of response to sensor data is beneficial in façade or interior wall applications where both a relationship with the environment and response to human activity is desired. Similar to study 2, imagine a façade that regulates heat gain and interior light levels. However, in this variation, the wall is also highly responsive to human activity. Views to the outside open up as a person approaches the wall from the inside. Conversely, a nosy outsider coming too close to the building causes the façade to clam up, obstructing views to the interior. Or perhaps the building is more welcoming than that, opening up as outsiders approach. In short, this scheme incorporates an overtly interactive relationship between the architecture and human occupant, be it inclusive, exclusive or other.