Inflatable Topography Module

Speculative Proposal / Conceptual Design: 

The members for this project are: Kaleb Crawford, George Wang, Ana Mernik and Jen Liu

Our vision for a tool for tending is a series of inflatable topography modules that create the floor of our biome. These interlocking modules are chambers that can deflate/inflate at different rates to create the most ideal situation for plant growth using fans and a valve system. The arrangements of modules can potentially accommodate water distribution, decomposition and allow for adequate sunlight positioning of plants in the biome.

In thinking of the garden, we decided that our goal was to encourage growth of the plants, whatever form it may take, in order to create a healthy biome. At first we were thinking of a “top-down” approach such as creating a robot arm that could tend to the needs of the plants. However, we decided to then consider the opposite, a “bottom-up” approach, and thinking of how we could modify the surface in this way. Also rather than thinking of a tool that lives in the biome, we also wanted to consider how we can think of the habitat as a whole - as sort of a living organism that can change depending on the conditions presented. In using inflatables and principles of soft robotics for our design, we are also less likely to damage the plants. By creating a modular floor, the biome can adapt to whatever conditions may occur during the 18 month period on Mars. 

Prototype: 

For our prototype we wanted to experiment with inflating different shapes and various methods of inflation. We used a wide variety of materials such as paper, plastic and fabric for this process. We first created a quick paper prototype that explored how the modules would sit together at various heights to create the changes in topography. A piece of cotton fabric sits on top of these chambers to create the surface that these plants would grow on.

Then we built a working prototype that demonstrates the mechanism of a single inflatable cell. The prototype consists of inflatable bag, air pump, solenoid valve and a constraint structure. You can control the speed of inflation by adjusting the air pump speed or the valve. Also, we observed that by changing the shape of constraint structure or the position of the weight on the platform you can change the behavior of the cell significantly. This provides us the potential of a flexible and versatile structure solution. 

Taking into consideration what we learned from this previous prototype, we decided to create an inflatable module that has a wide, square shape with built in structures. Using a vinyl fabric, we attached elastic bands to act as supports so that the module would be able to retain its shape even when deflated. By forming the module into a square shape, this would allow the modules to be easily interlocked with other pieces, rather than a cylindrical or pillow shaped module we were working with in our previous models. 

Paper prototype with four chambers

Vinyl fabric prototype of single square shaped inflatable module

Working prototype of a single cell

Precedents: 

Ant Farm, Environmints, 1970

We were inspired by different inflatable architectures and how they create these contained environments. Along with creating walls and ceiling, the landscape of the ground can also be changed and modified. For example, bouncy castles are inflatable environments where the floor is structured to provide adequate support for a human to jump around. In thinking of how we imagined our biome to flourish on its own with minimal tending, we were inspired to think about how individual inflated chambers could be altered to provide ideal growing conditions and reproduce processes such as decomposition in a closed environment. During the prototyping phase, we also looked at other inflatable objects in our everyday lives. One example that we used was water wings which is typically used for swimming assistance. Inspired by the ability of water wings to stay on an arm, we used its design as a basis for creating an inflatable artery, a tube that can constrict flow based on the inflation of the tube.  

Process: 

Describe how you arrived out the outcome. What iterations, refinements, design decisions and changes were made? Who did what?

The initial idea had to do with an inflatable biome from which a robotic arm with many tools for tending performs all the functions of the human hand. We then redefined our mission objectives and the scope of the project to reflect a bottom-up, hands-off approach: inflatable topography. Some analogies for this system we explored included veins and arteries, and root systems. 

And vessels and chambers. We also tied the shape of our biome to solar collection potentials, as well as plant containers, soil mixing, and water distribution.

A concept sketch of these pockets we’re calling inflatable chamber modules.

Following the initial brainstorming, a prototype in its “final form” was made to give a better visual idea of what we were working with.

Then came many smaller experiments. They had to do with different material properties.

And forces or seams imposed on them to create different shapes.

And sizes, folds, and strengths.

Our latest iteration and exploration attempted to add a structural component to the chambers, to allow control over the inflating and deflating, and the consequent shape of the inflated module. We strove for our unit to be a shape that is compact when scaled up and expanded upon.

Reflection: 

Primarily, this prototype helped us reconsider and question our technique in tending to a Martian Biome. Instead of considering technologies that were analogous to the ways that humans interact with plants and crops, we questioned how the environment itself could tend to the life it contained. Additionally, this prototype helped us realize the versatility of inflatable structures, and how minor changes to their construction changed the ways they behaved, as well as how a modular design approach gives us a great degree of flexibility in how we deal with challenges during the mission.

If we were to do this again, we would have experimented with a larger number of modules in order to test of our hypotheses about their collective behavior were true or if we would encounter unexpected problems.

Open Questions and Challenges: 

Looking forward, we would like not only continue to question our ideas about what robotic or embedded systems look like (and manifest as), but our notions of ‘traditional’ plot and soil based gardening, and if those can be adapted to a gardening system that offers more flexibility inherently (aquaponics, aeroponics, etc.) For example, if we could simplify the growing process, much of what our system offers would be unnecessary.

Some of the challenges we would face building this at scale would be determining the energy demands of multiple inflatable modules, evaluating if maintaining an air supply would be challenging in a Martian atmosphere, and seeing how well the system adapts to failure of specific modules.

Attribution: 

Reference any sources or materials used in the documentation or composition.

Soft Robotics:  https://www.youtube.com/watch?v=kHGLYRUKWeM

Flexible Solar Panel: http://goo.gl/W0NnYF

Inflatable Architecture:  https://www.youtube.com/watch?v=GVCo-WuUpH8