INTERACTION DESIGN
AeroSynth
An ultrasonic theremin you play with your hands, without ever touching it.
August 2026
— The theremin was one of the first electronic instruments, played by moving your hands through the air. AeroSynth reimagines it with two ultrasonic sensors and an Arduino: one hand shapes the pitch, the other sets the tempo, and together they turn empty space into music.
ROLE
CONCEPT, INTERACTION DESIGN, ENCLOSURE DESIGN, CIRCUIT DESIGN, EMBEDDED PROGRAMMING
Project Overview
Turning the space around you into an instrument.
Most instruments ask a lot before they give anything back: years of practice, trained fingers, and learning to read music. AeroSynth asks for nothing but movement. Bring your hand closer to the front sensor and the pitch changes; move your other hand above the top sensor and the rhythm speeds up or slows down. Anyone can start playing within seconds.
The aim was an instrument that feels intuitive rather than technical, proving that expressive, playful interaction doesn't need expensive hardware, just two sensors, a microcontroller, and a buzzer.
Approach
Fashion shooting in the studio
Mapping hand distance straight to frequency sounds chaotic, like a siren that never lands on a note. So instead of raw pitch, the distance picks a note from a C-major pentatonic scale. It's a five-note scale where every note sounds good next to every other, so there are no wrong notes. Whatever you play, it stays in tune.
The rhythm engine runs without pausing the processor, so the Arduino keeps reading both sensors while the beat plays. Tempo ranges from a quick 50-millisecond pulse to a slow 400-millisecond beat, depending on how close your hand is.
Process
Designing an invisible interface meant defining where the instrument begins and ends.
Each sensor reads a hand only within a set range, roughly 2 to 30 centimetres. Inside that zone, every movement shapes the sound; beyond it, the instrument simply ignores you. This keeps the play area clear and predictable, so walking past or stepping away doesn't trigger random notes. A short timeout on each sensor reading also keeps the system responsive when no hand is present, instead of freezing while it waits for an echo that never returns.
The space between your hands became the instrument.
Final Design
Sound Art
Interaction Design
creative technology
Physical Computing
The finished AeroSynth sits in a laser-cut wooden enclosure with two sensors, one facing up to control tempo and one facing forward to control pitch. Because the mappings live in code, either sensor can be reassigned to control something else, letting players experiment and develop their own style of playing.
The system is built to grow. Next steps include a third sensor for volume, a fourth for effects like echo and reverb, MIDI output to control music software such as Ableton, and laser time-of-flight sensors for more precise pitch control.
Product Images