Alfred, an office companion for indoor climate
A mechatronic mouse that reacts to noise and air quality
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Studio photo of the assembled Alfred prototype emerging from its enclosure, with a sensor-data laptop behind it
- Context
- How To Make Almost Anything, IT University of Copenhagen
- Year
- 2026
- Role
- CAD and mechanics
- Team size
- 3
- Tools
- Slider-crank mechanism · Servo motors · Sound sensor · MQ135 air quality sensor · Arduino · 3D printing
- Contribution
- Team of 3, all CAD drawings and the mechanics
A desk companion that makes invisible office conditions visible, being a mouse that emerges from its hole and reacts with its ears and head when noise or air quality cross a threshold. This is built from a slider-crank platform, servo motors, a sound sensor and an MQ135 air quality sensor, all in 3D-printed housings.
The idea
Noise and air quality in shared offices are real problems and largely go unnoticed until they are already bad, and existing products tend to signal them with a coloured light. Here we wanted to test whether physical movement and character would land better than another indicator lamp, since a thing that visibly reacts potentially gets attention that a colour change does not.
How it works
A slider-crank mechanism drives Alfred in and out of a mouse hole, while servo motors move the head and the ears, and a sound sensor together with an MQ135 air quality sensor feed the thresholds that determine his reactions. The housings were 3D printed and revised through several iterations.
What went wrong, honestly
The prototype did not work as a complete system, since the head we settled on is too heavy for the servo to tilt or even hold in position, and the body shell is oversized relative to the slider-crank we ended up with, which means that Alfred tips sideways and adds friction. We therefore tested the subsystems separately instead, starting with the ear reactions to noise and then the slider-crank travel with only the head and neck fitted, in order to confirm that the electronics, the mechanism and the software worked together even if the assembly did not. This is due to a long open ideation phase, since we experimented with head movement and considered articulated arms rather than ears, and while that exploration informed the final decisions it left too little time to iterate the printed parts once the mechanism was fixed. The lesson I took from it is to close ideation earlier and get the basic combination of electronics, mechanics and software working before refining anything.
Testing the sensors
We logged noise between 72 and 130 with an average of 104.78, and air pollution between 152 and 157 with an average of 153.4. However the air quality readings were too stable in the location we chose to trigger meaningful reactions, and in hindsight we should have tested in a small closed room where the air quality visibly degrades, rather than picking a threshold that almost nothing crossed.
What I owned
I was one of three on the project, and I did the CAD drawings, built and manufactured the physical prototype, and ran the sensor testing.
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Multi-view technical assembly drawing of Alfred, with servo motors and mechanism callouts
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Hand testing the servo-driven ear and head assembly on the bench
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Cardboard "Alfred's Home" mock-up with the fan-blade head mechanism and wiring exposed