Slime Farm
An IoT device to encourage hand washing habits for kids
Slime Farm is a connected physical–digital system where a faucet-mounted slime character responds to handwashing in real time.
Washing data syncs to a caregiver app, turning hygiene into a shared, playful routine that supports habit building through interaction rather than enforcement.
CATEROGY:
YEAR:
2025
EXPERIENCE:
IoT System Design / Embedded Firmware / Mobile App UX / API & Data Logic / Physical Prototyping
process.
Research
Children often rush through or skip proper handwashing due to low engagement, while most existing tools emphasize timing and compliance over motivation and understanding. Research on child habit formation suggests routines are more effective when learning is reinforced through visible cause and effect and play rather than enforcement.
Pain Points
Low engagement:
Caregiver fatigue:
Compliance focused tools:
Control vs independence:
Handwashing feels boring and is often rushed or skipped.
Repeated reminders and supervision create friction.
Timers and alerts enforce behavior without building understanding.
Caregivers need reassurance while children seek autonomy.
Design Framework
Based on the identified tensions between engagement, learning, and caregiver anxiety, Slime Farm was guided by three core criteria that informed all design decisions.
How might we use gamification to support children’s handwashing while encouraging learning and interaction between children and caregivers?
System concept
Slime Farm is a connected physical–digital system where a faucet-mounted slime character responds to handwashing through sensors and light feedback.
Washing data is sent to a companion app on the parent’s phone, where virtual slimes grow based on behavior, creating a shared feedback loop that supports learning and motivation for children.
Prototyping
Early prototyping focused on validating system behavior through a breadboard setup, testing sensor input, button interaction, and light feedback in real time.
This phase was used to refine responsiveness, timing, and cause-and-effect relationships before committing to form or enclosure design.
Physical Design
3D modeled and printed the slime character enclosure
Wired and soldered electronics into a stable protoboard
Integrated LEDs, buttons, and sensors into the physical form
Implemented backend logic to connect physical input with system feedback
Interaction Design
Built and coded the companion app interface and interaction flows
Mapped physical input to simple, engaging digital feedback
Refined interaction details to support clarity and motivation
final design.
IoT-Enabled Hygiene System
Wash events are detected by the device, processed locally, and transmitted to the backend. The companion app updates in real time, immediately logging and visualizing each activity as it occurs.
Wash State Classification & Feedback
The device evaluates wash duration and categorizes each event into one of three states:
• Dirty Slime: under 20 seconds
• Healthy Slime: 20 to 40 seconds
• Overwash Slime: over 40 seconds
The LED ring provides real-time progress signaling during the wash, and the resulting slime state is logged and visualized in the app immediately after completion.
Dashboard Analytics
A parent-facing dashboard summarizes hygiene activity across users. Wash frequency, duration quality, and state distribution can be filtered by day, week, month, or year. Individual user views allow caregivers to interpret behavioral patterns without interrupting the child’s experience.
Reward System & Gamification
Each completed wash generates a new slime and accumulates digital coins. Slimes act as visual records of interaction, while coins extend engagement through unlockable accessories. The system reinforces consistency through collection and progression rather than corrective feedback.
Multi-User System
The platform supports multiple child profiles within one household. Each profile maintains its own wash history, slime collection, and statistics. A no-user mode prevents untracked activity from interfering with recorded data.
Digital Reflection & Activity Logging
Each wash event is transmitted to the backend and instantly reflected in the app.
• Timestamped wash record
• Duration + state classification
• Auto-sorted by day / week / month / year
Every slime represents a logged interaction.
