Final design

This is the final ‘real’ design which should be used for manufacturing. The design is made to fit every component inside and should be everything our prototype was not. For illustrational purposes, the outer walls are not ‘frosted’. The changes are also mostly inside the AquaLumi, the outside has not been altered.


The part which is far more better than the prototype part, is the outer housing. This can be manufactured in such a way that every component fits exactly how it should and is in balance. There are four points on where the print circuit board can be fixed. Two batteries fit between these four points and the other two fit outside them. On the bottom are the added weight (for floating stability) and the charging coil.


Here is a better view of the battery placement.


The weight is positioned inside the coil and held in its place by its form. The coil is also form-fitting so it doesn’t move around inside. There are two capacitive strips and one capacitive point in the middle to make contact with the water. These are embedded in the inner shell and protrude through this shell. On the PCB should be sockets where the strips and point can be plugged in.


Close-up of the capacitve strip and point.


View of the weight and coil.


Here is a nice view of the PCB. The LEDs are integrated on the PCB which makes the whole more compact.

Final prototype

In this post we will try to make our final prototype as clear as possible. This is the prototype which we also exhibited on the ITD Exhbition. On the exploded view below you can see everything that is inside.



Inside the AquaLumi you can find:

  • Arduino Mini Pro
  • 3 x White/amber LEDs
  • 1 x Blue LED
  • 1 x Red LED
  • 3 x AAA Batteries
  • Depending on the specific prototype, we have added a number of weights to balance the AquaLumis in the water.


The features of our prototype are:

  • Control the light intensity and color by manipulating the amount of water inside the AquaLumi.
  • Depending on the waterlevel, it gives white/amber light, blue light and purplish light.
  • It can be totally submerged under water.

The outer shell was made of PETG which we vacuumshaped into the glass shape which can be seen in our previous post.


Above you see 5 white wires and 1 yellow wire which go through the inner shell and stick out on the inside. When the AquaLumi is filled with water, the white wires will make contact through the water with the yellow wire. This ensures the light can be controlled by the amount of water.


Because the AquaLumis are completely sealed, we need to charge them ‘through the air’ with an induction charger often found in electrical toothbrushes. Philips, however, also has luminaires made for underr water. We decided to buy one of these and see how these work. There is an induction charger supplied, which is pretty much the same technology and form factor as our design.

The software is programmed to create smooth transitions between the five states. So when the first connection is made with water, the first LED will gradually light instead of popping on instantly.


Five LEDs in total are inside one AquaLumi light; three white/ amber, one blue and one red. In the prototype, the first three connectors in the water will only manipulate the intensity of the three white LEDs. So when the first connector makes contact, all the white LEDs turn on and increase in brightness when more connections are made. When the fourth connector makes contact, the blue LED will gradually join the white LEDs. The same goes for the red LED when the fifth connector is submerged in the water.


Together with the refracting water and color combinations, this creates beautiful light effects on the surroundings.

Prototype building progress

Here is a photo collection showing the progress of our prototype.


testing the software/hardware


does it work with water?


these Aqualights don’t know what’s in store for them… 


one Aqualight is decapitated 


studying the innards of the Aqualight 


will the components fit in our shape? 


here they are in better times 


rotating the mold for vacuumshaping 


the vacuumshaped inner cup 


inner and outer cup with the molds in the background




sandblasted the outer cup for a frosted glass effect 


the prototype would be too light, so we added fishing leads to make it heavier 


will it still float?? 


it just floats above the surface with a full cup of water, perfect! 


don’t you just want to touch them? 


the resistors in our test-prototype 


the LED ‘spiders’ soldered in a compact module of 5 LEDs 


everything fits in our cups… 


to be continued…

Some minor changes…

As we mentioned before, the idea of having multiple AquaLumi’s together creating other colors is off the tracks. We decided the lights will change color when more water is added. The figure below illustrates the way the LEDs will react to the waterlevel.

Water level

As you can see, the first three levels only affect the brightness of the white LEDs. The fourth level triggers the blue LED and the fifth triggers the red LED.


Water level resistors

On the picture above the red wires are attached to the nano Arduino with a resistor in between. When the water reaches a certain level, the water will conduct electricity to these wires and the Arduino will control the LEDs accordingly.

Evaluation with philips

We had an evaluation meeting with Philips, where they would decide if our concept (or parts of our concept) would be eligible for a patent. After the meeting, they could not decide yet, since our concept had changed dramatically. But we asked them what their previous thoughts were about our concept, and they told us that it was one of the concepts that would be chosen for a patent. 
So that’s great!
These are the posters we showes them during the evaluation meeting. Their comment was that we should leave the communication between the lamps out. So we are switching to another idea. 
And that is…The colour of the light will change according to the amount of water that is poured in the lamp. The technology will be explained in further posts.
posters for client

The concept

The chosen shape and the new context are a surprisingly good combination. Another new feature of the concept is that the lamps are communication with each other, when they touch each other. We want to reach this by using 3 contact points per lamp. Look at the pictures below, then everything will become more clear. 
explaining the concept

New design

After the user test, we searched for a new shape that would fit in or around the bath.
Here are some sketches we made during the brainstorm. 
new shape sketches
Some more sketches..
more sketches
We chose for tis shape with a double wall:
 chosen shape

Iteration 4: Users

After the presentation for Philips, we performed a user test in two parts. In the first part, we showed our postcards to people and asked them a few questions.
interview with postcards
The conclusions from this part of the test were:
– The lamp fits to the Philips brand and into the Philips portfolio. 
– The shower is not very much preferred as a context, because there would be no time to use the lamp the way we intended. The shower is more functional, where people are in a hurry. They would not feel like using our lamp when they are in a hurry, altough playing with water under the shower would be nice.  
– The bath would be a much better option, since people are going in bath to relax and take the time for it. The bath has a better athmosphere. The lamp would fit in this environment very well.
– The edge of the bath would also be a nice place to put the lamps. The lamps could be used instead of candles. 
– Th bathroom will become more attractive.  
– The living room is a nice environment for the lamp, because you spend a lot of time there and you want to create a nice athmosphere there. 
– The interaction is very nice and poëtic. The fact that there is water in it and it gives light is special and cool. The users could not think of another function for the lamp.   
– The used colors of light are nice.  
– Solar energy could be used to charge the lamps.  
In the second part, we used the prototype. We settled up in the basement where we could arrange a dark environment, to see the effect of the light much better.
user test set up
participant during user test
These are the questions we asked to the participants:
1. What do you think this product is? 
2. Where in your house would you expect this product?
3. Please pour water in it. 
4. What are your first reactions?
5. Which color do you prefer the most?
6. This lamp is meant to be used in the bathroom. How would you use this lamp in the bathroom?
7. How would you use it in the living room?
8. What do you think about the weight and size? (the user friendliness)
9. Where do you want to use this product?
10. What do you think about the aspect of filling it with water? 
11. Do you have any suggestions for improvement? 
The conclusions from this test were:
– It’s a very nice idea.
– It’s a pity that you have to fill it every time again.
– The bath is a better environment than the shower. Small lamps around the bath. 
– The living room is also nice, since you relax there.  
– The lamp is a bit too big now.
– The effect on the ceiling is very nice and relaxing.  
With these conclusions we made some decisions. Wait for the next post! 


We made two postcards, which describe where we are in the concept development and contain a plan about the technology involved in the prototype that makes the concept experiential. 
The first postcard is the concept postcard. Here the concept is visualized and at the back there is a description of the concept.
concept postcard front
concept postcard back
The technology postcard consists of a diagram of the technical components that compose our prototype and their relationships.
technological postcard front
 technology postcard back