Case Study
“oh my gosh sorry i totally
forgot to respond!”
Both people miss each other. Neither person is doing anything wrong. The tool just wasn't built for this.
Long-distance relationships don't fall apart from lack of love — they drift from the friction of reaching out. Missed windows, timezone gaps, messages that imply replies no one has the bandwidth to send.
Lumo is a paired desk companion and mobile app designed to keep long-distance loved ones feeling close — through ambient light, proximity sensing, and shared voice notes. Built at CMU for Playful Interaction Design.
Role
Lead Mobile Designer
Context
CMU Playful IXD
Team
3 People
Deliverables
App + Physical Prototype
01 · Context
How it started
Working in a team of three — Manya Bhogilal, Zeana El-Hajomar, and myself — we were asked to design a playful interactive system that addressed a real human need. A shared thread kept surfacing in our early conversations: we were all far from people we cared about. Zeana and I are in different time zones from close friends and family. Manya had been thinking about the friction of asynchronous relationships. We started there.
HMW Question
“How might we recreate the feeling of embodied co-presence between long-distance loved ones?”
02 · Research
What already exists —
and why it falls short
Connection treated as an event, not a state.
BondTouch
Wristband that sends touch vibrations. Single-modality. Requires deliberate action to initiate every time.
LoveBox
Heart spins when partner sends a message. Charming, but requires the sender to pull out their phone and actively compose.
Pillow Talk
Heartbeat transmitted to pillow. Intimate but limited — no awareness, no message layer, no timezone context.
Hugging Pillow
Squeeze-triggered haptic. Physical and evocative — but the gesture doesn't scale to daily ambient presence.
Insight (Problem)
Design Implication
One-channel devices feel limited
Multi-modal cues: light, proximity, warmth, sound
Users value ambient presence
Automatic cues that run throughout the day without user effort
Micro-gestures create connection
Small, lightweight, optional interactions — not obligatory rituals
High setup cost kills daily use
Interactions must be intuitive and nearly zero friction
03 · The Problem
Messaging apps treat presence
like a transaction
The friction isn't emotional — both people clearly want to connect. The friction is structural. Every message implies a reply. Every reply requires the other person to be available, present, and in the right headspace to respond. Across timezones and full lives, that window almost never lines up.
01
No ambient awareness
You don't know if they're awake, at their desk, or on the other side of the world in the middle of their night. Timezone math is exhausting and easy to forget.
02
Every message demands a reply
Text threads are inherently conversational. A message implies a reply. That pressure erodes casual, low-stakes reaching out.
03
No record of presence
You don't see the pattern of when they're around. Each interaction lives in isolation — there's no shared rhythm visible to either person.
04 · The Solution
lumo
A pair of connected desk companions — one for each person — and a companion mobile app. The physical device handles passive, ambient awareness. The app extends that into message history, a shared timeline, and recording tools.
Physical Device — Four Interactions
Awareness
Day / night ambient light
The light sensor reads ambient light levels and transmits a day or night signal to the partner's device. No action required — Lumo just tells you whether your person is in sunlight or darkness.
Communication
Voice note via the heart button
Record a voice note on the app, then tap the heart button to send it to your partner's Lumo. Their green LED turns on when a message is waiting. They press a button to hear it.
Emotional Presence
Proximity-based heart glow
When you sit at your desk and approach your Lumo, the proximity sensor triggers a heart glow on your partner's device — brighter the closer you are. It signals: I'm here, at my desk, present.
Shared Connection
Synchronized heartbeat pulse
When both people interact with their devices within two minutes of each other, the hearts on both devices pulse simultaneously — a moment of unplanned, shared presence across distance.
Under the Hood
Built on two ESP32 microcontrollers communicating over ESP-NOW. Each device has an HC-SR04 ultrasonic proximity sensor, an LDR light sensor, a NeoPixel LED ring for the heart glow, indicator LEDs, a push button, and a small speaker for voice playback. The shell was 3D-printed, sanded, primed, and spray-painted.
The Lumo App — Four Screens
hover to play ↑
01
Home Screen
Greets you by name with a time-of-day gradient that mirrors both users' current times. The inbox surfaces waiting voice notes. A streak counter encourages sustained engagement without feeling punitive.
02
Timeline View
A vertical timeline with a gradient shifting from blue (night) to gold (day) shows both users' circadian contexts side-by-side. Voice notes appear as markers anchored to the time they were sent and received — so over days, you start to see each other's rhythms. A key constraint: a user cannot send a new message if they have an unread one waiting.
03
Recording Screen
A clean waveform interface for recording voice notes. Start, stop, re-record, confirm, then send to device. The confirmation step — "your message is on its way" — creates a sense of ritual and intentionality around each note sent.
04
Note History
A chronological log of incoming and outgoing notes, playable directly from the list. A streak counter and streak-break warning add a gentle motivation layer to stay in the habit of checking in.
Visual Direction
I anchored the app's visual identity in blues and golds — colors that echo the day/night theme of the device and feel calm and slightly nostalgic. Instrument Serif Italic for expressive headers, Albert Sans for clean UI text. The result is something that feels warm without being saccharine, digital without feeling cold.
“The timeline started as a wireframe problem — how do you show two people's days side by side? It ended up being the heart of the app: a visual proof that your rhythms overlap, even across distance.”
05 · Design Decisions
The choices that shaped Lumo
From humanoid to ambient
Our earliest sketches had faces, arms, and expressive eyes. The feedback was consistent: a human-like form would make users attach to the device itself, not feel more connected to the person at the other end. Once we stopped asking "what should it look like?" and started asking "what should it not look like?", the form simplified quickly — closer to a glowing pebble than a character.
Simplifying the interactions
Early on we had ideas for squeezing, hugging, and handshake gestures — all of which required mechanical parts and interaction complexity. We dropped the squeeze gesture entirely and reduced timezone syncing from a dynamic clock display to a single binary LED: day or night. Simple enough to read at a glance, meaningful enough to change how you think about reaching out.
Designing the timeline
The core question: how do you show two people's daily rhythms side by side without requiring mental math? I landed on a vertical timeline with a gradient background shifting from deep blue (night) to gold (day), with each user's context on either side of a central axis. One constraint simplified everything: a user can't send a new message if they have an unread one waiting. It kept the exchange feeling balanced and removed a whole class of edge cases.
06 · Limitations & Future
Where Lumo goes next
USB-powered only
Battery integration is the most critical next step. The USB cord fundamentally disrupts the 'just sit on your desk' fantasy.
No user testing
We validated ideas through feedback and casual checks, but never ran a proper long-term deployment study.
No haptic / warmth layer
Warmth and vibration were in our original vision but out of scope. They'd significantly deepen the emotional expressiveness without adding complexity.
The app has room to grow in directions the device can't. The timeline is currently a static record — but it could become predictive, surfacing patterns like “she's usually at her desk around 9am her time” and suggesting better windows to connect. The streak mechanic could evolve into something richer: shared rituals, recurring reminders, or a way to mark meaningful moments for both people to revisit.
“The bigger opportunity isn't a better messaging app. It's the space between messages — the ambient, automatic knowledge that the person you care about is still there.”