Dune House: Adapting to the Shifting Dunes

Hi, I'm Lincoln Clarke, and I'm going into grade 12 at Toronto French School.

A year ago, during my trip to Morocco, I stood atop the Erg Chebbi sand dunes and marveled at their beauty. It felt like I was on top of the world. It was the ultimate sense of freedom. I thought to myself how amazing it would be to live there and get that same feeling every day when stepping outside. Imagine that.

Yet, nobody lives permanently on the sand dunes. There are nomads and desert camps, but no permanent structures. At the time, I only thought of a couple reasons why people don't live on the Sahara dunes–One of the 7 natural wonders of Africa. It seemed like such a missed opportunity.

When I saw this contest, I was determined to build a permanent structure that would allow its inhabitants to enjoy the dunes while providing them with a comfortable habitat.

Software

• Fusion 360
• Cura
• Chitubox
• Arduino IDE

Tools

• Dual color FDM 3D printer
• Resin 3D printer
• Small screw drivers, flat head and Phillips

Materials

• ≈1.1 kg Beige PLA
• ≈200 g Black PLA
• ≈300 g Translucent PLA
• ≈200 g ABS like resin
• 16*M3 screws, 4-10 millimeters long (Shorter is quicker to screw in)
• Super Glue

Electronics

• 1*Old TV Remote
• 1*Arduino Nano
• 1*Arduino Nano Terminal Expansion Board
• 4*L298N Motor Driver
• 8*TT gear motor
• 1*2S 7.4 Volt LiPo Battery
• 1*Female JST Plug
• Jumper wires

I started by researching more reasons as to why people don't live permanently on the dunes. It turns out there are a lot, so it's understandable why locals avoid living on them despite their beauty.

The main problem at hand is dune migration: Dunes are in constant motion. The wind gradually blows the sand, and over time, this results in movement of up to 83 meters per year!

As a result, a static house is not an option, and the cases of Kolmanskop Namibia and al-Ghuraifa UAE are the living proof of that, as seen in the photos.

Other challenges

• Wind erosion and sandstorms: Even just the constant wind erosion from blowing sand will deteriorate structures, let alone full-blown sandstorms.
• Temperature extremes: Maintaining a comfortable temperature inside is difficult when Sahara temperatures soar up to 50°C in the day and can plummet to around -6°C at night.
• Low precipitation: The Sahara receives an average of only 76 millimeters precipitation per year. Drinking water is a challenge, as is growing food.

Dunes aren't the only landscape that moves. In the Arctic, snow accumulation poses a similar issue as dune migration, and engineers have defeated this challenge when building Arctic research stations.

Halley VI research station is built on a floating ice shelf, where the ground isn't fixed. Snow accumulates in the winter, followed by partial melting in the summer. Halley VI implements a dynamic design that can adapt to the ground: Each pod is built on retractable skis, which allows them to rise above the new snow level and avoid being buried.

Not getting buried

Inspired by Halley VI, the house will be comprised of modular pods, each built on legs. But, in the desert, the issue of accumulation is amplified. Snow will only accumulate so high and eventually it melts. Dunes on the other hand, can be thousands of feet tall. Instead of simply rising up and down from the same reference level, the pods will actually need to "stomp" on the sand so that the house can avoid being buried no matter how tall the dune is. When the house gets buried, it will retract one leg at a time, while standing on the other legs, and then put that leg back down on top of the sand.

The GIF above shows how this would look for a single pod.

Drinking water

Surprisingly, the Sahara desert has an average humidity of 25%, which is enough to use an atmospheric water generation (AWG) device, which extracts moisture from the air to produce water. Suitable solutions already exist, like Watergen, which is capable of providing hundreds of liters of water daily. Such a unit can be powered with solar panels. To further increase efficiency, less contaminated wastewater like that from showers would be filtered and recycled.

Temperature Extremes

Both air conditioning and heating will be required, making a heat pump the best option. It will be powered by solar. In addition, multiple layers of insulation will be used to increase efficiency. Since the modules are on retractable legs, weight should be minimized, so traditional Adobe bricks aren't an option. We can however use an Adobe plaster coating on the outside, building the house the same way one would with stucco. Adobe plaster provides some insulation and makes the house blend in with its environment. Between the metal framing and drywall, we can use insulation with a high R-value (Great thermal performance) to further increase efficiency.

Sandstorms

The main issue here is that the solar panels would get dusty, and would need to be cleaned. We'll make the roof easily accessible by including a ladder and a place to lock the ladder into the roof.

Inspired by the Bee'ah headquarters in the United Arab Emirates, the house will blend into the dunes with a wavy roof. This will also provide shade, giving the inhabitants a comfortable place from which they can enjoy the view.

My Dune House concept is a modular design consisting of hexagonal pods on retractable legs. The modular design allows for easy adjustment to the house size based on the inhabitants' needs. Meanwhile, the retractable legs protect the home from being buried by sand.

This household is self-sustaining despite being off the grid. Solar power, which is abundant in the Sahara, gives them an almost limitless source of energy. With one pod dedicated to water and HVAC and another for a greenhouse, nutritional needs are fulfilled

In this 5 pod concept, the inhabitants don't just merely survive in the desert, they thrive.

With a separate pod for working, living, and sleeping, the inhabitants are able to separate the different aspects of their lives and achieve work life balance. While they will be in the middle of nowhere, they can still get internet access through satellite providers, like Starlink. This way they can stay connected with the world around them while being at one with nature.

Each hexagonal pod will be 4.7 meters wide, giving a circumscribed radius of 2.35 meters. The pods will all be 2.4 meters high (ceiling height).

The shaded spaces outside are also crucial to this concept. They give the inhabitants even more space for leisure, and promote outdoor activities. The inhabitants can sit back and marvel at the vast expanse, or they can have a barbecue and the list goes on. These porches can also be used as a garage for a Jeep.

The dunes are full of great activities:

• Sandboarding
• Dune buggy rides
• Hiking
• Stargazing

This concept embraces its unique surroundings to provide its inhabitants with a life like no other–One where they permanently experience the sense of freedom that comes with being on the dunes.

The physical prototype will be a 1:36 scale model (2.77%):

Circumscribed radius of pods: 2350 mm * 2.77 / 100 = 65 mm

Height of pods: 2400 mm * 2.77 / 100 = 66.5 mm

There will be 5 pods in total, as in the layout shown above. The house will integrate motors and Arduino to provide fully functional retractable legs, controlled with an infrared remote. To be pragmatic, the center pod won't have retractable legs: Its weight can easily be supported by surrounding pods and it makes the robotics integration simpler. The rest of the pods will have 2 legs each. All in all, the house will be sitting on 8 retractable legs.

I'll design my prototype using Fusion 360. The final model is linked below.

Each of the pods consists of a shell with the outer walls and the windows. The pods are connected with walkways, which fit together using grooves.

I'll use dual color 3D printing so the windows and walkways, which would be glass in real life, are clear. The clear walkways are designed so that they're strongly bonded to the beige shell they go with, as seen circled in red. Having the 2 plastics just touch risks them coming apart, but this way, with the transparent part locking in behind the outer surface of the beige part, it's strong (see picture with this circled in red). The windows of the prototype don't need as much strength, because they don't need to hold anything together like the walkways do. Accordingly, I didn't incorporate this extra degree of strength for the windows.

The big picture configuration is shown in the last picture.

The pods' shells include a D-shaped hole for retractable legs and a mount for the TT gear motor that sits on top of each leg. Each leg is essentially its own mini linear actuator. The leg is in a D-shaped "track", so the screw connected to the motor moves it up and down and the leg won't just turn in the hole. Because of the screw, the assembly cannot be mirrored to the opposite side of the pod (Unless you want the screw going the opposite direction, but that just makes assembly more complex). So, I only designed one of these leg-screw assemblies, and will just print 8 of them.

The motor is mounted with 2 pegs which go in its mounting holes, and on top there's a motor mount cover, which is screwed in with M3 screws.

This is all shown clearly in the video with the exploded view above.

To mimic the shape of sand dunes, I used the loft tool. First, I created 3 sketches on different planes to define the roof's shape at different heights. Then I used the loft tool to create a dune like roof. After that, I used a rectangular pattern to create the solar panels and then extruded them onto the surface. Finally, I split everything up into main roof and solar panel components, and I split the whole thing into 3 pieces so it would fit on my printer.

Next, I created roof inserts that allow the roof to snap into the hexagonal pods. Then, I cut holes in the roof for these inserts so they can easily be installed. Some parts of the roof were too thin to cut holes for these inserts, but it's okay if a couple are missing because it's still securely attached.

I did something similar with the roof for the greenhouse, except for the fact I had to use guide rails because the shape was self intersecting otherwise.

Now that the design is finished, we can create renderings! For the parts that would be adobe plaster, I modified the cement appearance using an adobe plaster texture. For the greenhouse, I used acrylic.

Dual color printing is key in this section as it allows seamless integration of parts like windows, and solar panels. All parts that require dual color printing are designed in 2 separate STL files–one for each color–and need to be merged in Cura.

Pods

The greenhouse is translucent.

The rest of the pods are dual color, using beige for the pods' main shells, and translucent for the windows and walkways that connect them.

Print one of the 2-door pods, one of the 3-door pods (center), and two of the 1-door pods.

Don't forget to use supports for the clear inserts, which sit just a bit off the build plate, as seen in the picture.

Roof

The greenhouse roof is clear.

The main roof for all the other pods is in 3 pieces (Big end, Middle, Small end), which are all dual color. The "main canopy" is beige, to blend in with the dunes, and the solar panels are black. Each one of those 3 pieces are hence split into 2 separate STLs.

Print one of each roof connector, which serve to connect the 3 pieces of the main roof.

The roof inserts allow the roof to snap into the pods. Print 10 of the inserts for the main roof, and 3 for the greenhouse roof. (There are only 10 and not 12 for the main roof because some of the spots where there would be an insert are too thin. 10 is more than enough though for it to be secure on top of the pods) These are best printed in clear so they stay invisible.

Other parts

The motor fastener should also be printed clear so you can't see it

I suggest printing the person walking in black so it shows up well.

These parts need high resolution printing, so resin is ideal. That said, high quality FDM printers could print them well too.

I used Anycubic ABS-like resin Pro 2, which performed really well.

Orientation and supports are key to successful resin printing. Everything should be printed on supports (I used 3 mm elevation), and the legs should be angled to avoid printing a large surface all at once (I used 15 degrees which worked well).

Leaving these parts to dry after washing in IPA is especially important since they have holes where the alcohol can sit and not evaporate quickly.

Print 8 legs and 8 screws for the retractable leg mechanism.

1. Using the roof connectors, assemble the 3 pieces of the main roof with super glue.
2. Using one of the motors and a 3-6 volt power supply (Or you can do it manually), screw the screws into the legs about half way.
3. Assemble the modular pods, sliding the walkway connectors of each pod into the next using the grooves. Use super glue at the bottom (The floor of the walkway) and in the grooves)
4. Put the connected pods up on a raised platform like a box and insert a leg with a screw in it into one of the bottom holes. On the top, connect a motor to the screw. The motor shaft does fit snugly, but use super glue as well just to make sure, especially for when the motor is lifting the legs up and their weight is hanging on the shaft. Push the motor downwards, aligning the pegs in the pod with the mounting holes of the motor
5. Screw in the motor fastener on top of the motor.
6. Repeat steps 4-5 on all 8 motors.
7. Using a 3-6 V power supply, individually retract all the legs to their maximum retraction so that all pods are at the same height.
8. Superglue the roof inserts in the slots provided for them in both the main roof and the greenhouse roof. The taller inserts are for the main roof and the shorter ones are for the greenhouse roof.
9. Snap in both roofs and you're done with the physical parts!

Looking at my remote, the following will satisfy the needs of this project:

The up button will extend the legs, making the house move up.

The down button will retract the legs, making the house move down.

3 motion modes: All Legs, Single Pod, or Single Leg

Yellow Button: Single leg

Red Button: Single pod

Green Button: All pods

Different amounts of time the motors can be set to run for

Eject Button: 100 ms

Sleep Button: 400 ms

Bluetooth Button: 800 ms

Function Button: 1500 ms

Football Button: 2000 ms

The leg or pod number

In the case of modes single pod or single leg, the number can be specified with the number pad. I've assigned numbers to each leg and pod, and I've written them in sharpie inside each pod. The picture shows pod #4, which has legs #7 and #8.

Pods: 1-4

Legs: 1-8

We need to find the codes emitted by the remote on the press of each button.

1. Connect the Arduino to just the IR receiver, as shown in the picture.
2. Use the IR remote test program attached below to find the code for each button.
3. Create a case in the program for each button's code

1. Connect both motors in each pod to a single L298N motor driver.
2. Connect the 7.4V power wire from the JST plug to the VIN and GND pins on the Arduino and to the power terminal on all the L298N drivers. Since the one wire needs feed multiple boards, I split it with lever nut splicing connectors. Soldering would be another option.
3. Connect the IN 1,2,3,4 pins of the L298N drivers to the Arduino with jumper wires. There are 16 pins to control in total, so you do need to use the analog pins as digital outputs, which works perfectly fine.
4. In the dune house code, assign the correct pin numbers to each of the IN 1,2,3,4 pins of the motor drivers.

There’s a 50/50 shot of getting the code right the first time, since upward motion is one wire on high and the other on low and downwards motion is the opposite.

Using the single leg mode, test each leg by pressing the up and down buttons. If the pod goes in the opposite direction than you pressed on the remote, then that motor's function in the code needs to be changed. Switch the HIGH, LOW to LOW, HIGH.

Before taking a photoshoot of the prototype, I wanted to make a picnic table so the inhabitants can have family meals out under the sun shade.

I built a miniature picnic table by gluing together toothpicks with super glue.

I used real sand to simulate a dune!

My vision is for Dune House to give its inhabitants a feeling of freedom and appreciation of nature every minute of the day. I know my experience standing in awe on the Moroccan dunes really marked me, and I can only dream of what it would be like to stand atop a dune every day. Imagine what it would be like to have your morning coffee on the dunes, or to go for a walk! Personally, this would uplift me every day and improve my spirits. This is the beauty of the Dune House concept: It connects its inhabitants with nature, ultimately improving their lives. It embraces the charm of the dunes while being resilient to their harsh conditions.