A2: Model Prototype Smart Shower Interface

Assignment A2 is a model prototype for “a shower control interface for a high-end, multi-feature valve and temperature control.” Desired features are as follows:

  • product controls and interface/display must fit within the dimensions of approximately 4 x 4 x 2 in volume
  • product weight is approximately .75 pounds, and should be able to be mounted on a wall
  • digital display will show settings such as temperature, water flow volume, valves (this could be used to control whether water comes out of the tub spout, the shower head, a handheld wand)
  • Physical affordances and controls must be easy to use when visibility and dexterity are challenged by soapy hands, steamy showers, and absence of corrective lenses

We were also asked to think of the brand OXO as an inspiration, and create something “well-designed, comfortable and easy to use.”

The Design

A2 sketch 1
My original sketches for the model prototype. Click the image to enlarge.
A2 sketch 2
I also considered different materials. Knowing that cardboard would be hard to shape into a dome, I also briefly considered building a geodesic dome instead of trying to curve the cardboard. In the end, however, I ended up using Styrofoam. Click the image to enlarge.

For this design, I started off thinking that I wanted the shower control to be round and slightly raised, something similar in shape to the shield that Captain America uses. I figured that a smooth, round device would be safer in a shower, and that if someone fell they would be hurt less if the interface didn’t have any corners.

The shower control has three main buttons to switch between settings (water volume control, temperature control, and valve control) and a slider that slides around the entire circumference in order to adjust these settings.

For many devices that have a similar shape, such as the Nest, adjustments are made by turning the entire outer portion of the circle. In my original design, I decided against this because I thought that it might be more difficult for someone to turn a large dial like that in the shower, when things are slipperier. I imagined that the slider could have some sort of grip, or have indented sides so that it would be easier to grab. Additionally, someone could also push the slider with their finger, making it easy to use.

The shower control display would show the three settings, with the current setting that can be adjusted being presented as the largest. Pressing a different button makes that setting the current setting, makes it the largest item presented on the display, and also allows it to be changed by using the slider. The large display items/buttons help with visibility in the shower.

The Prototype

A2 first prototype
This is my first iteration of the prototype. It’s a bit hard to see the difference between the two iterations, but this first iteration had a rougher slider, and did not indicate which direction to push the slider to increase or decrease a setting.
A2 second prototype
Among other things, this prototype was smoother, sturdier, and had a smoother slider motion. A red mark was added to indicate which direction corresponded with increase/decrease

The model prototype was constructed using Styrofoam, black masking tape, magnets, paper, sponges, markers, and some clay.

One of the biggest challenges in creating this prototype was getting the shape right. I started by using a Styrofoam half-sphere I bought at the craft store, and shaved it down. In the end it was not as flat as a Captain America shield, but I was pleased with the overall shape, and smoothness. The buttons were made using some sponge, so that the buttons would feel more button-like to a test participant.

The slider was perhaps the most challenging aspect of this prototype, as I could not construct an actual slider to go around a Styrofoam dome. In the first iteration of the prototype, I used thin weak magnets around the outer rim of the dome, and also attached a magnet to the slider I made out of clay. This did not work out so well, and the slider kept falling off. In addition, the sliding motion was not as smooth as I would have liked. I also tried attaching the slider with string, but that did not help very much.

In the end, I used a strong magnet on the slider piece and covered the magnets with tape to help imitate a smooth sliding motion.

Analysis after testing

After the initial test, several issues with the prototype became apparent, which caused me to make some changes.

The first thing the participant noted was that they could not tell which way to push the slider in order to increase or decrease a setting. Apparently this function differs from shower to shower. However, it seems that most showers have “hotter” as counter-clockwise, which is opposite of what I had originally thought. To fix this, I placed a red arrow indicating the direction of increasing temperature/volume.

In addition, the first prototype was not well built– buttons fell off during testing, and the motion of the slider was not smooth. These were fixed with the second iteration of the prototype.

One thing that came up during a class critique (after the second prototype) was the lack of an “on” button, which I would probably add to subsequent prototypes. However, there was some debate about whether or not the volume control could also function as an “on” button. To turn off the shower, one would decrease the volume of water to 0.



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