Octofungi is an interactive sculpture that exhibits simple reflexive autonomous behavior, learns its surroundings and interacts with them.
Several ideas are being addressed in this sculpture. At an aesthetic level it is about the duality of symmetry and asymmetry where both condition can exist in one piece. This phenomenon can be seen all around us in nature but also is deeply rooted in the law of physics of our universe as well as in all forms of life.
The idea of symbiosis and our endangerment by ignoring its importance in the wellbeing of our world, and ultimately our own existence. Octofungi meaning Octopus and fungi or mushroom, represents the interdependence between species in our world, and as we deplete our environment we are weakening our chance of survival in the long term.
It is about behavior, and how it is possible to emulate living behaviors with electronics and simple neural networks, and ponder on what defines life. What differentiates living matter from inanimate matter. It explores the principle of emergence and how the combined efforts of multiple simple systems can result in behaviors not seen individually.
Octofungi is a sculpture that stands on a pedestal. The pedestal houses a transformer used to power eight legs and a regulated power supply used to feed the brain and sensors. This is the only external connection to the sculpture; no remote controls or external computers are used in this art piece.
All you need to do to use Octofungi is: plug it in!
Octofungi is a reactive piece. It is sensitive to changes in light and reacts upon these changes. To interact with the sculpture, a person only needs to move his hands above the eight light sensors placed around the brain frame. Depending on the "aggressiveness" or "gentleness" of the participant, Octofungi will manifest different behaviors.
In the genetic brain version currently under development, more complex behaviors will emerge as Octofungi learns new patterns associated with sequences of responses. These behaviors will be more subtle and will need more dexterity from the participant since brutal movements will inevitably trigger instinctual reactions. So, being gentle and patient will produce a more surprising and rewarding experience with Octofungi.
Traditionally, artists try to capture the life of nature through art. With Octofungi, I tried to take this approach one step further by using the brushes of technology. I am attempting to trigger questions about the relationship between animate life and artificially animated objects. I am also trying to persuade people to reexamine our definition of life.
Is life limited to what we know or can it go beyond our present understanding?
Octofungi is quite a complex system but it lacks elements I would consider indispensable to any life form. First it does not look for food. If we consider the intake of energy as eating, Octofungi is fed intravenously, but it does not "know" that it needs to eat and it does not know how to get food. However, plants are also "wired" in a sense to the nutrients in the ground and to the sun's energy. Plants, however, know how to search for these nutrients and energy by moving their roots or leaves closer to the sources.
Although a future version of Octofungi will have a genetically engineered brain, the genetic evolution and sexual reproduction will not be carried out by Octofungi directly, but by an external computer which will simulate specific conditions for a large population of virtual Octofungies. Similarly, some species of fungus emit spores which use the reproductive organs of a host to reproduce. In this respect, Octofungi mimics biological life.
Although Octofungi presents some of the same elements as simple life forms, it still lacks full autonomy. Only Octofungi's behaviors are presently controlled by Octofungi's will. Nonetheless, I believe that the line that separates the living from the inert is more fuzzy than we think.
Octofungi's awareness at present is purely instinctual; it has no higher thought processes. It is probably comparable to a non-social insect such as a moth or to a mollusc such as a snail. With the genetic brain currently under development, I hope to reach or exceed the behavioral complexity of a fish.
Octofungi is for sale. If you are interested you can contact me by fax at 480-991-8547 or by using the contact form.
Octofungi is a product of three previous versions. Each successive generation has evolved because of physical constraints such as cost, gravity, and technological availabilities.
For example, one of the last generations of Octofungi was made of a resin that was very appealing aesthetically but failed to satisfy physical requirements. It was too heavy and too brittle to withstand mechanical stresses. The latest design was made of a polyurethane which was not as pleasing as the resin, but the piece was improved aesthetically by a more intricate and lighter structure.
Octofungi is currently getting a new brain. As this new brain is genetically engineered, the outcome of the implementation is highly unpredictable, but highly promising. Future sculptures will also benefit from this research and more "living sculptures" are under development. So stay in touch!
Octofungi's brain is going to undergo a major revision. Currently, it simulates the base of the spine in a human being, the spine being the center of reflexive behavior. The first modification will be the placement of an "overseer" brain on top of the "reflex" brain. The overseer will examine the inputs received by the reflex brain and find patterns of inputs via a true neural network. The reflex brain is not capable of seeing time-dependent sequences of inputs, but the overseer will be. The overseer will also be capable of giving the legs time-dependent output based on these patterns.
The upshot of all this is as follows: Octofungi will recognize sequences of movements and reply with sequences. Octofungi will also be able to learn new sequences since the overseer brain will be a true neural network.
Next will come a genetically programmed neural network. The network is derived by placing a base population of networks into a software shell in which they can compete, breed and mutate. The weights of the interconnections between neurons can change genetically, as can the mathematical rules by which the neurotransmitters migrate from one neuron to another. Even the basic structure of the neurons can change. With this technique, Yves hopes to derive a network structure that is optimized for Octofungi's brain. In addition, different Octofungis can be given different genetic brains. Since the brains will have different genotypes, or genetic structures, the brains will have different phenotypes, or behaviors.
The body will probably be completely redesigned. The current body is not actually a prototype - there was an earlier version - but this body is the first we have made since implementing many changes, most notably the leg sensors. Currently, there is a slight ambient light problem with these sensors that was alleviated by placing "mustaches" around them but a new design should alleviate this problem.
The body also needs to become lighter. The muscle wire can only lift a certain weight, and currently the body is slightly heavier than it should be…
Although I tried to keep its cost as low as possible, Octofungi is an expensive sculpture because of its technological complexity. Every Octofungi is built in my home studio. Every mechanical, electronic and physical part of Octofungi was developed, assembled and tested under these conditions. Octofungi is not a production-line product, it is a sculpture which was built with love and passion just for the sake of curiosity, aesthetics, and research into the imaginary and into dreams. My only hope is that public places such as galleries and museums will consider purchasing this work so that it can be available to anyone who wishes to interact with Octofungi. However, because Octofungi needs to be trained, a one-on-one relationship is most likely to give the best results and be the most rewarding for art collectors.
The body is where most of the force generated by the piece's weight and by the muscle wires is dissipated. The vertebrate-looking rings are tension rings that hold the shoulders and legs in place. This interlocking technology alleviates the need for screws and other metal fasteners, allowing Octofungi to keep his weight down. Finally, the body contains the two spine boards.
Octofungi is designed to lock together without any screws or other hardware fasteners. The key to this locking mechanism is the "stars" (pictured to the left) which support the body at the top and bottom. Each shoulder has a series of pins which fit into the vertebrate-like rings (pictured below).
These rings surround a tube, which in turn surrounds the spine boards. The shoulders are locked into place by the two stars. The legs snap around the shoulders with the same pin technique. So, essentially, the entire piece is held together by the stars at the top and bottom of the body and the rings in the middle of the body.
Octofungi is made from a polyurethane base that combines low weight with high strength. The polyurethane is an extremely strong plastic that can resist minor shocks. The prototype of Octofungi used a conventional resin, but this proved infeasible due to the resin's extreme brittleness.
Added to the polyurethane base are nutshell fiber powder, soybean flour, and micro glass beads. These increase strength while decreasing overall weight. The composition of the body was dictated by the need to find the highest strength to weight ratio possible without destroying the aesthetics of the piece. This goal was necessitated by the need to support the force generated by the muscle wire.
Octofungi's total weight is about 2.5 kg and the total lift provided by the legs is about two inches.
Electrically, the heart of Octofungi is four Microchip PIC microcontrollers. These microcontrollers use a RISC architecture to achieve high speeds combined with low programming overheads. In addition, the brain sports five kilobytes of EEPROM memory. This memory is used for the neurotransmitters of the neural network. The microcontrollers get the inputs from the eyes by way of an eight channel A/D converter. The four microcontrollers reside in two circuit boards arranged in a flying saucer configuration. These two boards and the spine boards communicate by way of a central "spine connector."
The spine boards carry signals to and from the legs. One is a simple electrical conduit, while the other translated low voltage microcontroller signals to higher voltage muscle wire signals with logic level MOSFETs.
The electrical section is the leg sensors. These determine the position of the legs at any given time and feed it to the brain where all of the actual processing is done.
Finally, in Octofungi's pedestal is a five volt power supply for the brain and a twelve volt rectified supply for the muscle wires.
Inside Octofungi's body are two "spine" boards. These got their names by simulating functions of the human spine. One of the boards, the sensor spine board, transfers signals from the leg sensors to the brain. This function is an analogue to the sensor neurons found in the animal kingdom. The other spine board is the driver board. This board translated the brain's low voltage signals into the higher voltage signals that the muscle wire needs to operate. This is accomplished with a bank of simple MOSFET switches. The driver spine board simulates the motor neurons in a human body.
Octofungi has eight eyes. These eyes are actually cadmium sulfide cells whose resistances vary inversely to the intensity of light striking them. The eyes are multiplexed through an analog to digital converter, which then feeds their signals to the brain. The eyes point up and out from the body, enabling Octofungi to see its surroundings. Unlike a human, Octofungi can see in all directions simultaneously due to the placement of its eyes. However, Octofungi is extremely myopic and can only see for about two feet. These eyes are the only sense that Octofungi possesses.
Interaction with Octofungi is achieved by changing the light hitting any eye. Usually, this is accomplished by waving one's hands over Octofungi's head, although people have done things like turning out lights, teaming up to cover all its eyes, and using a flashlight in a dark room.
Octofungi's current brain structure gives interesting results when Octofungi is left alone in a room with a window. As the sun moves across the sky, Octofungi will occasionally sit up to look at it, then sit down again. When night comes, Octofungi will go to sleep, although he will still stir occasionally. If someone comes into the room and turns on the lights, all of Octofungi's legs will extend fully.
Theoretically, Octofungi should be capable of distinguishing different people's movements from one another. See what's in store for information about new brain software that may make this possible.
Octofungi's brain currently performs only reflexive behavior. The brain tells the eyes to open every 1.5 seconds. The eyes return to the brain the intensity of light hitting them at that instant. The brain processes this information through a simplified eight dimensional Kohonen neural network. A Kohonen network is a software analogue of the biological structure of a brain; that is, it contains software neurons which interact by way of software neurotransmitters. Octofungi's current brain, however, is using a simplified version of this neural network which only learns Octofungi's environment. The brain compares the information from the eyes with Octofungi's learned environment to determine whether anything is moving. If something is, the brain will react with either an instinctive "flinch" to simulate fear or an instinctive attraction to simulate curiosity.
Octofungi can react to changing ambient conditions. As conditions change, Octofungi will observe the change and readjust its environmental map accordingly.
Octofungi can also become bored. If it doesn't see any changing conditions for a while, Octofungi will move around a bit on its own.
The heart of the brain is four Microchip 16C57 PIC microcontrollers. These microcontrollers contain software to control the legs, the leg sensors, feedback, input from the eyes, and filtering of the inputs. The brain also connects to the spine.
Download the simulator used to create this version of Octofungi's brain (Mac app.):
> FAT version > PPC version > 68k version
> Download the brain developer's kit
The shoulder takes the majority of the stress induced by the muscle wire. It also holds the spring that returns the legs to their contracted positions and the sensors that tell the legs' positions at any given time. In addition, the shoulders support the brain and the eyes. The pins on the insides of the shoulders are part of the locking mechanism that holds Octofungi together without any screws or metal fasteners.
The shoulders are designed to accommodate 160 newtons of force between the muscle wire anchor points and the pulley. They also accommodate the same force between the spring and the leg anchoring point. This force is equivalent to a 17 kg (37 pound) weight. The legs' design shows a meld of strength maximization, weight minimization, and overall aesthetics.
Octofungi's legs are driven by a memory shape alloy wire, also known as a muscle wire. As the wire is heated by passing electrical current through it, the wire contracts. Octofungi's weight and/or a pair of springs then pull the leg back to its original position. Due to the non-linear reaction of the muscle wire, Octofungi's leg utilizes a reverse-bias pulley. This pulley necessitates a greater amount of force when the leg is first opening and a smaller amount of force when the leg is almost fully extended. For the spring, this force reaction is opposite. The pulley increases the moment the leg sees as the leg opens. With this reverse-bias pulley, we translate the non-linear reaction of the muscle wire into a "closer-to-linear" reaction.
The leg also holds the non-repeating binary bit code that the leg sensor uses to determine the position of any leg at any time. The leg has Teflon glider-feet that allow for easy movement, reducing the strain on the muscle wire due to static and kinetic friction.
Looking at the leg, one should be able to see that it minimizes weight (a problem with the muscle wire) while maximizing strength, all without losing the aesthetics of the piece.
The leg sensors are composed of two small (about 1 inch by 3/4 inch) circuit boards that "sandwich" each leg. On one of the boards is a Texas Instruments sensor which records light intensity in 64 pixels. On the other board is a micro-light-emitting-diode. In between is a mylar strip with a non-repeating binary bar code imprinted on it. As the light emitting diode shines through the mylar, it creates a pattern of shadows on the pixels of the sensor. Since the code on the mylar is non-repeating, the "window" of 64 pixels is sufficient to give the leg's absolute position at any time. The light intensities of each pixel on each leg are transmitted to the brain every 8.33 milliseconds. In the brain, the pulse patterns from the sensors are decoded into an absolute position for each leg. This allows the brain to drive the muscle wire to a specific position instead of fully extended or fully contracted as it is usually used. The brain also contains sophisticated error checking software to avoid spurious sensor readings and to keep the muscle wire from overheating.
Muscle wire, also known as memory wire or memory shape alloy is a titanium nickel alloy that returns to a preset shape at a preset temperature. In Octofungi, the preset temperature is about 200 degrees fahrenheit. At this temperature, the wire contracts by about 3.5%. This contraction is translated over the length of the 17 inch wire into a range of motion for the legs of about 70 degrees.
The wire has a "programmed" temperature at which it has a "programmed" shape. When the wire cools, it goes back to a non-programmed shape. As the wire is heated, it tries to return to its programmed shape. Hence, the wire has two possible states. There is the cooled state (temperature) at which the wire can be stretched, and the programmed state (temperature) at which the wire returns to its programmed length. At the programmed state, the wire exhibits a crystalline structure known as austenite. As the wire cools, the structure changes to martensite, which is a herringbone shaped crystal lattice. The martensite is much more flexible than the austenite, allowing the cooled wire to expand. When the wire is heated to its transformation temperature, the structure reverts to austenite and the wire contracts. When in the austenite state, the wire is much more susceptible to stress, which can damage the wire. In addition, the resistance of the wire changes as the crystalline structure changes, making the wire difficult to control.
Muscle wire has found many application in the bio-medical field, the most notable of which is probably a method to aid in the treatment of aneurisms. It is also used as a catheter guide, an orthodontic arch shaper, and to join pipe ends together.