Header Student Manual Interactive Environments


Aeolus, in Greek mythology, is known as the ruler of the wind. This interactive dynamic inflatable environment, named Aeolus, gives you the opportunity to become just that. Through amplification of your own breath you can give life to shapes that surround you, although it is only through collaboration with others, that you’d be able to achieve the full potential of the installation and create the closed inflatable space around you with all the colours and the movements.

On this picture, Aeolus is fully operational. All the lights are on and all the seven inflatables are inflated. On the floor there is a red carpet. We chose a red carpet to show people that the environment is open and that everyone is welcome to our installation. All the inflatables have a slightly different form and size. This is done to make every inflatable more individualistic.
The idea of the installation was to stimulate interaction between people. We did this by luring people in the installation and create an environment around them. In this way they suddenly found themselves in a closed space, which created a bond.
There are three “propellers” in the middle. Two inflatables of the same color react to one propeller. The connected inflatables are always opposite to each other. The seventh inflatable, which had no color, only inflated when all three the propellers detected input. So you have to be with three persons to inflate all the inflatables.

These are the propellers the user blows into to inflate the inflatables. The propellers are laser cut and sandblasted plastic. The propellers are attached to an adjustable tube, called a gooseneck, to make the installation accessible for children and adults. What you see in the picture are two users blowing on the propellers and checking which inflatable reacted on their blowing. That is why a fast reaction time was important for our installation. Every propeller was connected to an inflatable in front of them and behind them, so users could always see the reaction of the inflatable while they were blowing.

At the beginning of the minor we were quiet unsure if the users would blow a propeller. Because it is not a natural thing to do. So we looked at everything people blow into. Eventually we chose for a child’s toy so people wouldn’t be ashamed to blow in the propeller

In this picture you see Samuel and Floor interacting together with two other persons. Because the installation is made for three persons, we sometimes had to step in to bring the environment to its full potential. In this situation it might not have been necessary though, as there is a potential third person just outside of the environment. This would have been excellent conditions to see if those people would actually start to engage in social interaction with each other. It would have been hard for Samuel and Floor to assess the situation as such though.
During the week we exhibited the environment at Industrial Design, we nevertheless got to observe these kind of situations. Most if the time that people were interacting they already knew each other, but there were some instances where users found theirselves in front of perfect strangers. For the people that decided in that moment to blow into a bunch of small windmills together, this playfully awkward moment has hopefully lowered their social barriers.

The actuators of the installation were these three little windmills. The idea for this form was an obvious choice from the beginning, as they are reminiscent to most people’s childhood. We considered other options and ideas, but none of those were conceptually better or more functional. The only worry was whether or not users would be interested and triggered enough to blow into one. A quick-and-dirty user-test at the faculty of Architecture showed us they were.
Although the basic idea was clear in an early stage, a lot of additions were made during the design process. Because of this, and because it was one of the more detailed parts of the installation, it was finished as one of the last parts. The implementation of the LED’s for instance, was done in a late stage in support of the interaction.
The windmills self were lasercutted out of transparent plastic. This was then sandpapered to give it a matt finish to accompany the look of the inflatables and to let the light from the LED’s shine through. They are connected to a shield that holds all the electronics, which was also lasercutted from transparent plastic, only thicker.
The electronics consist of two LED’s, an infrared sensor, and all necessary wiring. This is where the magic happens. The sensor continuously sends out infrared signals in the direction of the windmill, at the back of which are reflective and non-reflective eights of a circle alternately distributed. According to the time between signals received by the sensor, the speed at which the windmill is spinning can be calculated. This data is then used to control the ventilators inside the inflatables. This neat little trick was tipped to us by the electronics man of Industrial Design, Rob Luxen!
The shield is in turn connected to a piece of gooseneck tubing, which’ rigid flexibility makes good for a very size, age and mobility-friendly device. These unique qualities make this material very hard to come by; we were only able to find one Dutch company that sold it: ET Projects. Luckily for us, they were so nice to provide us with five meters of the stuff for free!

Here we have a closer inspection of what goes on inside the environment. We see Samuel working together with Joost Broekens and his friend, to try and enclose the space around them. Joost was the minor’s tutor from the faculty of Computer Science. He was specialized in affective computing, but could provide you with a sober insight on almost everything.
What is most notable in this picture is the inflatable in the top right. Although all inputs are triggered, this one appears to be unaffected. This is because this is the seventh, ‘special’ inflatable. Only when the reward is achieved, by having three people blow into three windmills for a certain time, the seventh inflatable will take shape and illuminate with white light. This was done to give users a hint of the goal of the installation; if none of the windmills controls that inflatable directly, it must only go up if all are triggered.
To make this more clear, it was later changed to being inflated with as much power as there are windmills being triggered. I.e. if one is triggered, it only blows up with 33% of its potential. This gave the same effect, but without giving the people the idea that it is broken.

The forms of the inflatables have been a great field of exploration during the project. Through the process we got to know the materials better and how they responded on flowing air.
Main principals in designing the form are size, shape and behavior. Size, because we want people to experience they’ve gotten big output out of small input. The shape is important because next to the ‘big output’ story, we want people to make their own spaces. With the big width of the forms, just above your head, we’ve tried to come close. As last and maybe most important part, there is the behavior. Because flowing air always wants to make round sections in the material, and we didn’t want too much creases and insecurity about how it looks inflated, we decided to actually use that fact as a design tool. Thereby the forms are designed out of lofted circular shapes. In the picture above you can see the forms, built up by horizontal circles. What also had influence on our design was the power of the ventilators under the forms. We maximized the size without paying too much for slow reaction.

On this picture, you can see the inflatables positioned in the final design. The positioning has been quite an interesting theme in especially our interaction design. Important for us was the fact that the environment could engage people to socialize with each other. Very early in the process, we have thought of ways to realize that. The final positioning has played a big part in achieving this goal. Because the forms are positioned around the middle stand, and there’s barely space between them, people could actually form and experience walls and a room. That is not only unusual, but it also draws new spatial boundaries. Those boundaries made people feel ‘that they suddenly felt in a room’. Apart from that, this let to feelings of closeness and even intimacy. Sometimes people from ‘outside the space’ waited until people inside left, or started to look what’s inside.

The individual inflatables each have their own power supply. Using computer power supplies was a budget choice since we could get them sponsored by “Ansje Tweedehansje”. The 12V output on the power supply powers the circuit. The circuit consists of a MOSFET driver IC driving a MOSFET which in turn drives the fan. The circuit needed to be revised at several point in the project because the MOSFET’s kept overheating. This was solved by introducing the MOSFET driver. The circuit was now working fine by itself, but created problems when all circuits where used at the same time.
Using second hand power supplies with different power ratings and connecting the signal grounds together introduced a ground loop. The ground loop made all the different circuits dependent on each other resulting in unwanted behavior (fans turning when they weren’t supposed to and fans refusing to turn at full speed). Adding an optocoupler to each circuit resolved these issues since the power supplies could no longer influence each other. A problem that persisted even during the exhibition was the fact that the power supplies would turn themselves off when confronted with a current greater than their peak current. This was the result of inrush current created in the fans during startup. We attempted to resolve this problem by tinkering with the code timing, but looking back on this problem we should have included a current limiter in the circuit.

The Arduino code was pretty straightforward:

  • Detect motion from the small input fans.
  • Transform this data into output.
  • Send this output to the large fans.

Taking inspiration from the motion detecting capabilities of old computer mice we decided to use an infrared reflection sensor to measure the reflectiveness of the back of the small fans. These small fans had reflective material stuck to parts on the back in such a way that a fan turning at a constant speed would result in a square wave in the sensor output. The code picked up transitions between the highs and lows of this wave and by measuring the time between these transitions we were able to tell the speed at which it was turning. However, mapping this speed directly to the motors would result in a large inrush current in the large fans, turning off the power supplies. Instead, the output to the motors tried to follow the speed of the fans but was constrained to a maximum and minimum change over time. This allowed us to tinker with the “responsiveness” of the installation. The last thing added to the code was an idle state that was activated whenever the sensors hadn’t measured a transition for a certain amount of time.


At the very beginning of this project we had to decide what materials the environment would consist of. An interactive inflatable is not easy to realize; we needed strong, yet light fabrics in order to have it respond as quick as possible.

After an afternoon chat with Erik van Dongen (Air Design Studio) we came to the conclusion the strongest and most light-weight fabric was spinnaker, the kind of fabrics also used for sail boats and kites. For safety reasons we chose to use the M1 certified fire-retardant spinnaker, which was a lot harder to get our hands on. After a lot of phone calls we finally managed to get the fabrics with a student discount from Germany. We used at least 100 stretched meters of the fabric to realize the seven inflatables.

To connect the inflatables to the stand in the middle our environment required wiring between the objects. To cover this up, we decided to use carpet. Apart from its practical function, the carpet had a nice way of pre-defining the space and emphasizing the fluffy-ness of the environment. We got 60 square meters of free carpet from Edel Tapijt.

We used some of the carpet as the covers of the boxes, which made it blend nicely with the rest of the environment and kept the boxes from drawing too much attention from the inflatables. Apart from that it allowed us to attach the covers of the boxes with Velcro fastener. This made it very easy to take the cover off and on and allowed us to work on our project faster.

For the boxes we used MDF wood, because we wanted to mill the boards in a specific form and MDF is best suited for such a tool. It was very important that the wood would be milled, because it operates with great precision. As we were working with millimeters and circumferences, this was the best way to go.

From the beginning we were very ambitious to add light to our environment. It is a nice interactive element and very impressive when used properly. Choosing the color of the fabrics we knew it had to be white, in order to leave room for our big, final plan with the inflatables.

We experienced with light early on and we discovered it is hard to realize, as a lot of lamps get really hot and don’t diffuse but focus their light. Later on we took our shot with fluorescent lamps, which don’t heat up and do diffuse and are on top of that very cheap. It proved to be a bull’s eye; we were afraid the light wouldn’t be impressive in daylight, but the fluorescent lamps were very strong and were even impressive in bright areas.

At this point we were looking for a solution to add color. Of course changing color would be coolest, but the price tag here was too big. Instead we decided to go for colored covers: covers specially made for fluorescent lamps to change their colors. These covers came in very handy; even dark colors were still very bright from a distance.

Using color allowed us to provide more feedback to the user: if the user now blows into the little fans, the corresponding inflatables will inflate and share the same color! In this way, it is clear that one fan correspond with the yellow inflatables, the second with the pink and the third with the green. With the great finish, the only white one would go up. Clear feedback and very impressive to watch.

Because our environment would be very big and contain moving objects, it was very important the user would feel safe and comfortable. We wanted to create a safe space, provoking communication and co-operation.

The inflatables are white and big and look very sweet and friendly. They are rounded shapes, which don’t look very hostile, rather comforting and innocent. Users have pointed them out as “cuddly” more than once and occasionally users started to peddle or even cuddle them spontaneously. They invite playfulness and ensure a pleasant surprise for anyone who interacts with them.

Together with the soft carpet and matching boxes the environment got a very soft appearance. The small fans in the middle of the space were also looking very “cute” (as users often pointed out) and would even remind some persons to their childhood, when they would play with such mills. Everybody knows them and a person’s first association will usually be positive: “I know this from when I was younger, I used to play with those.”, which is always a good point to start at.

At the start of the process, we made four sub-teams in the Aeolus-group. We did this because working with eight people on the same things isn’t very efficient and we wanted to use talents of the individuals to strengthen the concept. Hereby we made four teams of two students, who designed one theme. Theme’s we used were Design, Materials, Interaction and Engineering. This led to easier planning and clear division of all the work that had to be done.
Although we have had the ‘endless debates’ and the wrong communications, I can say that the segmentation really helped. In the beginning of the minor-semester, we all learned the different aspects of designing interactive environments, from learning Arduino to modeling in Grasshopper. With that in the back of our minds, we had time to specialize ourselves in the subgroups. Because every student had his or her own field of interests and background, we explicitly used those talents to gain more for Aeolus.  What was very nice was that we knew about the work of the other teams, so the communication in the group went all by all quite easy.

The boxes underneath the inflatables are an import aspect in the functionality of the installation. Such a box contains a big fan, the power supply and all the electronics needed to control the movement of the inflatables on top.
In order to have enough space for all the components and provide the inflatables with a sufficient airflow, the boxes need to be designed carefully. Not only for the balance and the stability, but also for the assemblage, the boxes were designed as a tight fit construction kit which could be put together without glue or any nails. The boxes were drawn first on paper and afterwards in a 3D CAD program. In this software we could split the model into several parts with precise dimensions.
To get these precise construction elements in wood, we used a CNC (computer-controlled) milling machine which milled out all the parts of the boxes. As you can see on the picture, we nested all the parts in large MDF plates of 12 mm thickness.  Afterwards the software controlled the CNC milling machine to cut them out, so we could puzzle the pieces together and build in the fan, the power supply and the electronics.
The boxes were ready and only needed a cover to hide all the electronic parts. These covers are made from the red carpet and wrapped around the wooden boxes in order to give the end result a nice look and feel.

The inflatables are made from certified flame retardant spinnaker. It was not easy to find a supplier for the flame retardant version of the light weighted but strong fabric.
Just like the boxes, the inflatables are designed in a 3D CAD program which gave us the opportunity to make a parametric design. In order to get an interesting environment, build up with inflatables, we chose to design seven different inflatables based on the same principle. The CAD software provided us with the patterns from the different parts of inflatables which should be drawn on the spinnaker and afterwards stitched together.
In order to get the same accuracy in the inflatables as in the designed 3D model, the patterns were drawn and cut out by a CNC cutting machine. We found a company (Zeildoek BV) which liked to help us with the production of the different parts of the inflatables. From a role of four meters wide, the computer-controlled cutting machine cut out all the different parts.
Back in our own workplace, the stitching of the inflatables could start. All the different parts had their own numbers so we could easily find the parts that belonged together. As you can see on the picture, with a lot of man hours and two sewing machines, seven inflatables were born.

On this picture you can see the first time we fully tested the environment. We finally could get an impression of how the environment felt and if people would interact with it. This was a great success. Of course we ran into a few problems which we had not foreseen.

We had for example a few technical problems. One of them was that the power supplies we were using couldn’t handle the high amperage the fans used. The computer supplies have a build in safety that they turn off when the amperage or voltage is too high. So once in a while a computer supply didn’t work anymore.
The other  technical problem we found out, were the sensors on the tiny fans people blow into. The sensors sometimes came into the aluminum pipe. The result of that was that the sensor got polluted data, because it was reading the reflection of the aluminum pipe.

What we also found out this day was that the blue carpet was actually a threshold of people entering the environment. This came to light when we saw people actually doing their best to avoid the carpet. We couldn’t imagine the effect of the carpet would be this big. In the final design we gave the carpet an organic and irregular form in order to not create a clear delineated space.

We noticed that once people came into the environment, the atmosphere was very nice. People started talking without knowing each other.

We noticed a few tiny problems we had to work on to make the environment fully operational. In noticing the problems we got a lot of help from the users who talked about their opinion and feelings about the installation.
One of the problems was the airflow which was not good enough. The inflatable’s fell totally over the boxes. So the air could not get inside the inflatable because the inflatable closed it off. But when it finally could get enough air to lift the inflatable up, it went aggressively fast. This wasn’t an effect we wanted, because the users didn’t get the feedback of their input fast enough.

The second problem we ran into was that the telescope’s inside the inflatable’s did not worked out perfect. They bended too much so that they did not fold in properly. So once in  a while the inflatable stood right up while it was empty. (You can see one inflatable with this problem on the photo.)

At the end of the project, we did an exposition at the faculty of Industrial Design. We could test our final installation and observe people watching and interacting with it.
The feeling you get when standing at a distance is completely different as when you are close to the installation, or even inside of it. The feeling of curiosity is already here when you are watching from a distance. You see things moving in front of you, not exactly knowing what’s happening inside. You see those inflatables rising and getting bigger and suddenly you can’t see the people inside anymore, because they are enclosed by the inflatables.
When getting a little closer you see it’s happening inside and that you have to blow in a little fan to activate the inflatable. When knowing this it is also very fun to watch people interacting from a distance.
At the exhibition week at the faculty of Industrial Design, lots of people were looking from the bleu corridor in the picture, so they saw it from above. People were watching other people interacting with it. They were discussing this and laughing about it. So it was fun for the people interacting with it and fun for the people watching the other people interacting.
In this picture you can also see the color linked inflatables. Both inflatables of the same color rise at the same time, so even from a distance you can understand the game.

Softness: that’s what you first think about when you see this inflatables. They look like soft, sweet, cute, huggable creatures. At a distance, like in this picture you can’t see this softness. The inflatable looks more like a colored balloon. When you are inside the installation, you can really feel the texture of the inflatables. You can see the fabric defolding and growing.  Standing close to the inflatable you can hear the sound the fabric makes when moving. You can also hear the sound of the ventilators blowing the inflatables up. It makes them kind of alive creatures. The form of the inflatables is quite vague, which makes people free to fantasize about their own form. Everyone sees something else in it.
In the beginning the inflatables were white colored. Then we added some colored lights: pink, yellow and green. These colors made the people around the installation feel happy.

By adding some stitches in it we could create curved forms in the inflatable. When blown up the inflatable is quite hard. Because of its soft look lots of people tried to hug it. The inflatables give people happy feelings. Feelings of hugging and like in this picture even being nice and kind for the inflatable.