⏰
⚙️

Total Weight

6.3 kg

📏

Arm Length

60 cm (12 segments)

🔄

Rotation Range

135° coverage arc

📐

Height Adjust

10 cm range

⏱️

Setup Time

< 2 minutes

✅

Success Rate

100% (10/10 trials)

Circadian Rhythm Regulating Device

A Mechanical Wake-Up Solution Using Physical Stimulation to Enforce Healthy Sleep Schedules

🎯 Project Overview

Traditional alarm clocks fail 43% of users who develop snooze habits, leading to unhealthy sleep cycles and morning tiredness. The Circadian Rhythm Regulating Device tackles this challenge with a mechanical solution that eliminates the snooze option entirely.

This ME 101 team project uses gentle physical stimulation—tickling combined with water spraying—to force users out of bed. The device features a rotating arm with a paintbrush end effector, ultrasonic sensor for presence detection, and a gravity-fed water system, all controlled by an EV3 microcontroller.

100%
Spec Compliance
10/10
Safety Tests Passed
6.3kg
Total Device Weight
< 2min
Average Setup Time

🔑 Need Statement

"A need exists to develop a mechanical solution that enforces wake-up routines while ensuring safe user operation."

The device addresses this through four main subsystems working in concert: the segmented arm and carriage for motion coverage, the bearing-supported arm axle housing for smooth rotation, the gravity-fed water system for secondary stimulation, and the adjustable body structure for accommodation of different bed heights.

📸 Design & Development Gallery

Explore the mechanical systems, CAD designs, and testing process behind the Circadian Rhythm Regulating Device.

⚡ My Contributions

🖥️ CAD Design & Component Modeling

  • Designed water system base in SolidWorks integrating motor mounting, valve holders, gear housing, and elevated water tower with lid—ensuring proper component spacing and structural integrity
  • Created 3D models for multiple critical components including the valve-gear connector with specialized geometry for mechanical linkage, screw-on clamps for secure valve mounting, and spacers preventing pin wobble in height adjustment system
  • Modeled ultrasonic sensor enclosure in SolidWorks with precise cutouts for sensor placement and LEGO pin mounting holes for adjustable rail attachment
  • Utilized imported STEP files of LEGO components and published dimensional standards to ensure precise fit and compatibility with existing EV3 ecosystem

🏗️ Manufacturing & Assembly

  • Executed fabrication of body structure using laser-cut HDF sheets with carefully planned joint locations and assembly sequence
  • 3D printed all custom components (water system base, connectors, clamps, sensor housing, spacers) with optimized print settings balancing strength, print time, and material usage
  • Assembled complete water system integrating motor, valve, gearing, tubing, and tank—troubleshooting alignment issues and implementing zip-tie reinforcement for valve stability
  • Led full device integration combining all four major subsystems (arm, housing, water, body) and coordinated component positioning for optimal functionality

💻 Software Development & Control Logic

  • Programmed valve control function in RobotC implementing motor rotation to open/close valve based on Boolean state parameter and gear ratio, with encoder-based position tracking ensuring precise 90° valve actuation
  • Developed robust error handling and state management ensuring valve returns to known positions and preventing water system failures during multi-phase operation
  • Integrated valve control into larger program flow coordinating with arm motion, sensor inputs, and phase transitions for seamless wake-up cycle execution
  • Contributed to system-level debugging and testing, identifying and resolving integration issues between mechanical systems and software control

🔬 Testing & Documentation

  • Conducted water system leak testing under various operating conditions including continuous maximum flow, rapid valve cycling, and extended duration tests—implementing improvements based on observed failure modes
  • Performed component fit verification for all custom-designed parts ensuring proper clearances, alignment, and assembly sequence before final integration
  • Participated in full-system user testing trials collecting data on setup time, safety, and device performance across diverse body types and sleeping positions
  • Contributed to final engineering report documentation including technical drawings, system descriptions, testing procedures, and results analysis

🤝 Project Management & Collaboration

  • Coordinated closely with teammates working on arm design, housing systems, and software development to ensure compatible interfaces and integrated functionality
  • Maintained organized work breakdown structure tracking water system tasks including design (3 hrs), CAD (3 hrs), assembly (4 hrs), programming (1.5 hrs), and testing/refinement (2 hrs)
  • Adapted to schedule revisions when primary subsystems encountered delays, shifting water system development timeline while maintaining project milestones
  • Participated in design reviews and team meetings providing technical input on mechanical feasibility, manufacturing constraints, and integration challenges

💡 Design Journey

From biological research to working prototype - the evolution of a circadian-optimized lighting system

01
🎯

Needs Analysis & Concept Development

User Research Requirements Definition Morphological Matrix Decision Matrix

💡 Key Insight: Research revealed that 43% of British adults who use alarms also snooze regularly, leading to disrupted circadian rhythms and morning tiredness. The team developed a comprehensive need statement: "A need exists to develop a mechanical solution that enforces wake-up routines while ensuring safe user operation." Three concepts were evaluated using a decision-making matrix—Concept 1 (rotating arm with feather and gravity-fed shower head) scored highest for user convenience, ease of fabrication, and cost, despite slightly lower effectiveness scores compared to more complex gantry system designs.

02
📐

Detailed Mechanical Design & CAD

SolidWorks Modeling Mechanism Design Material Selection DFM Analysis

💡 Key Insight: The segmented arm design emerged as a breakthrough solution balancing multiple constraints. Rather than machining a single 60cm arm (expensive, time-consuming, inflexible), the team designed 12 modular 5cm PLA segments with rack teeth matching LEGO pinion gear specifications. This approach reduced cost to under $10, enabled rapid 3D printing fabrication, allowed variable length configuration, and simplified repair. The bearing-supported housing required precise SolidWorks modeling using imported STEP files to ensure proper LEGO gear mounting—testing later confirmed that the bearing implementation reduced friction so dramatically that minimal motor power was needed.

03
🔧

Fabrication, Manufacturing & Integration

3D Printing (PLA) Laser Cutting (HDF) Machining (Aluminum) System Integration

💡 Key Insight: Manufacturing revealed critical integration challenges, particularly with the water system. Initial valve mounting proved unstable during operation, requiring redesign of clamping system with zip-tie reinforcement at two points. The valve-gear connector required multiple iterations to achieve reliable mechanical linkage—the final design used a specialized shape gripping the valve switch on one side and holes engaging the gear on the other. Assembly sequence proved crucial: certain components had to be installed before others were mounted, requiring disassembly and reassembly when this wasn't planned correctly. The team learned to thoroughly validate component fit and assembly order before final integration.

04
💻

Software Development & Control Algorithms

RobotC Programming Sensor Integration Motor Control State Machine Logic

💡 Key Insight: The arm's axle rotation didn't maintain a 1:1 ratio with motor encoder values due to gear backlash and mechanical tolerances, causing overswing issues. The team implemented physical arm rotation stops (bumpers) to mechanically constrain the 135° swing arc, then added time-based constraints in software rather than relying solely on encoder values. This hybrid mechanical-software approach proved more reliable. The multi-phase program structure (timer setup → probe state → initiation phase 1 with tickling → initiation phase 2 with water → relapse detection) required careful state management and void function returns to enable touch sensor interruption at any point in the cycle.

05
🔬

Testing, Validation & Performance Verification

User Testing (n=10) Safety Validation Performance Metrics Specification Compliance

💡 Key Insight: Comprehensive testing with 10 participants of varying body types validated perfect specification compliance: 100% reported safe tickling force (exceeding the 80% target), zero eye contact with water (validated via safety glasses inspection), all users completed setup in under 2 minutes, and ultrasonic sensor achieved 100% detection accuracy across various sleeping positions. Physical measurements confirmed 6.3kg weight (37% under limit), 135° rotation (delivering 60cm arc vs. 40cm requirement), and 10cm height adjustment (2× specification). The paintbrush end effector proved superior to initial feather concept—stiff enough to avoid deformation yet soft enough for safety, with naturally ticklish bristles. Device successfully met need statement by enforcing wake-up routines through persistent physical stimulation while maintaining complete safety.