POM^2: Pill Organizing Machine

UCI Theta Tau

2024

1/Summary

Summary

Developed a modular pill organizing machine for Alzheimer’s patients, designed to have four compartments for daily dosage scheduling.

Engineered dispensing slots with clearance tolerances to accommodate various pill sizes, reducing risk of jamming or misfeeds.

Validated the design through iterative FDM 3D-printed prototypes, refining tolerances, fit, and user interaction before final assembly.

3mm Wooden Fiberboard Housing

Acrylic Plexiglass Panel

3D Printed (PLA) Feeder Tray

3D Printed (PLA) Dispensing Mechanism

3D Printed (PLA) Catch Tray

3D Printed (PLA) Guide Ramp

3mm Wooden Fiberboard Housing

2/Design Breakdown

Compartment Housing - Exploded View

Housing

Loading Door

Top Plate

Side Wall

Back Plate

Sight and Access Panel

Side Wall

Base Plate

Dispensing Door with Aperture

The housing portion of the compartments is constructed from six 3mm laser-cut fiberboard pieces and one transparent acrylic sight panel. The fiberboard components are connected through multiple end box joints eliminating the need for screws. The acrylic sight panel slides onto the compartment between two 3D printed slots (not shown). This design emphasizes manufacturability, modularity, and user accessibility, providing a clean enclosure for the dispensing mechanism. 

Electronics Compartment Exploded View

Access/Top Plate

Rear Plate

Side Plate

Dispensing Mechanism

Dispensing Mechanism - Exploded View

Stop Pin

Selector Cap

Shaft Collar

Drive Shaft

9g Micro Servo

4 Hole Design Choice

  • Four dispensing holes based on average capsule sizing.

  • Hole Sizes based height of capsule sizes 1-4.

  • Capsule height 1 is 5mm where the height increases by an increment of 5mm for each size increase.

  • Hole diameter = capsule height

Enhanced Grip

Ridges on selector cap were cut to improve ergonomics and ensure reliable manual operation. The surface increases friction between user and cap, reducing slip. This feature enhances tactile feedback and supports consistent alignment with sizing disk.

How Pills are Dispensed

A servo-driven shaft indexes the sizing disk to match user-defined pill dimensions. The selector cap masks all but one aperture, allowing a pill to drop from the feeder into the exposed hole. The disk then performs a 360° rotation, transferring the pill through the dispensing chute into the catch tray.

Side Plate

Cable Feedthrough Plate

Base Plate

Sizing Disk

Pill Drop Opening