ENG EK 210 · Principles of Engineering Design · Fall 2025

SOAP. DISPENSER

Automatic touchless soap dispenser using IR laser break sensing and a linear actuator — designed for EPIC, our Engineering lab at Boston University.

See the build ↓ ← All work
Arduino
SolidWorks
OnShape
ArduinoIR Sensor3D PrintingSolderingSolidWorksOnShapeTinkerCadArduinoIR Sensor3D PrintingSolderingSolidWorksOnShapeTinkerCad
01Project brief

The brief.

Course
ENG EK 210
Period
Sep – Dec 2025
My Role
IR Sensor Team Lead
Tools Used
ArduinoSolidWorksOnShapeTinkerCad3D PrintingSolderingIR Laser Sensor
02Goals

What we set out to do.

01

Design an automatic soap dispenser for EPIC that delivers a controlled volume with no contact points to enhance hygiene and user convenience.

02

Develop a modular, sensor-driven system integrating an IR laser break sensor with a linear actuator for reliable, touchless dispensing.

03

Optimize for reliability, cost efficiency, and ease of maintenance to support large-scale implementation across the facility.

03My contribution

What I did.

Contribution

IR Sensor Team Lead

  • Responsible for all coding, wiring, and physical implementation of the IR laser break sensor system.
  • Designed the sensor logic in Arduino C — including debounce, trigger threshold, and actuator timing.
  • Debugged and iterated on sensor placement to reduce false triggers and improve detection reliability.
Contribution

3D Design

  • Assisted in 3D modeling the housing for the dispenser product in SolidWorks and OnShape.
  • Designed and 3D printed the soap pump cover to protect the linear actuator interface.
  • Measured GOJO bottle dimensions to ensure proper fit and alignment of the actuator contact point.