Pressure ulcers, also known as bed sores, are an affliction that breaks down the skin and underlying tissue when an area of skin is placed under consistent pressure. Despite being a preventable affliction, pressure ulcers still affect 3 million adults in the U.S., costing hospitals and patients an average of $37 800 per hospital stay.

For my engineering capstone project, my group and I built a smart mattress topper, with over a dozen air cells that use pressure sensors and compressed air to improve blood flow and comfort by autonomously adjusting the pressure in the appropriate air cell. The system was paired with a mobile app that we developed to allow real-time monitoring and control. Our goal was to reduce both the labour-intensive nature of pressure ulcer care, and provide a solution that can also be used outside of the hospital, for instance at nursing homes and private residences.

For this project, I led the firmware implementation, while supporting electrical integration and system integration with the mobile app. The system consisted of 16 piezoresistive sensors & one-way valves which were interfaced with a Raspberry Pi and Arduino using I2C and solenoid drivers, respectively. The Raspberry Pi acted as a server for the mobile app to connect with using REST APIs.

My favourite course during my 3rd year at the University of Waterloo was definitely ME380 – Mechanical Engineering Design Workshop. The course revolved around a term project where each group of students had to design and build a pick-and-place robotic arm that follows a set of constraints and requirements, and two additional requirements chosen by the groups.

Our team chose to design a manipulator that was also autonomous and capable of dealing with objects that had complex geometries. This meant that the manipulator needed to detect objects, calculate the required movements to get to the object, and handle objects that are difficult to grasp.

In our group, I was focused on the electric and firmware aspects of the manipulator, including computer vision, circuit design, and motor control based on inverse kinematics. However, everyone on the team was very multi-disciplinary and involved in all major design decisions.

Our final product was a 6-DOF robot arm that had 2 stepper motors and 3 servo motors. The gripper and linkages were mainly 3D-printed. A laptop was connected to a camera to perform object detection and inverse kinematics calculations, with control commands sent from the laptop to an Arduino through UART.

During my co-op, the engineers at Electrans Technologies had completed the design of their robotic system and were transitioning to its assembly and integration into commercial vehicles. The system would be an Electronic Control Unit (ECU) on the vehicle’s CAN network. As Electrans makes this transition, it is crucial that they verify the design of the printed circuit board (PCB), firmware, and hardware implementations before they are integrated in the final system. This lets engineers detect faults in their design early in a lower-risk environment, and prevents bottlenecks in the verification process by waiting for the full assembly.

The objective of this project was to design and build a Hardware-in-Loop (HIL) Test fixture that verifies the design and functionality of the ECU’s PCB and firmware. The details of the ECU are confidential and therefore are not included below.

The project involved reducing the number of hardware components to a model that produces an equivalent environment and electrical signals, mounting all components ergonomically for an operator to easily manage, and developing an interface for the operator to mimic the interactions that the ECU would have with a heavy-duty vehicle on the CAN network.

This was a subproject for my Hardware-in-Loop (HIL) Test fixture project.

After the HIL test fixture had been initially assembled and tested, there were three main areas of improvement. First, the operator's switches were too small and soldered too close together which made it difficult to toggle one switch without affecting another. Second, the LCD was also tilted at an angle that made it difficult to see when standing above the test fixture. Finally, all wiring should be hidden or strapped down to prevent it from interfering with the test fixture’s main electrical harness.

As a solution, I designed and 3D printed an enclosure to ergonomically mount the LCD screen & switches, and conceal the Arduino & its wiring from the test fixture.

For this project I modelled two different metal brackets in Solidworks that would support large pneumatic cylinders for a prototype. I then created engineering drawings of both brackets in SolidWorks to be sent to an overseas manufacturer.

The brackets were manufactured, passed quality assurance, and installed on a commerical vehicle for a pilot program.

As I was exposed to new aspects of engineering from my co-ops, I realized that I was still quite unfamiliar with electronics, firmware, and printed circuit boards (PCBs). Since I would not get much exposure to these concepts during my mechanical engineering degree, I decided to build an arduino-powered quadcopter.

As a starting point, I found an electrical schematic for an arduino-powered quadcopter online, and based my project on it. I wanted to avoid pre-built drone kits to properly learn the engineering concepts I was applying and experience sourcing individual components for a project which is a key component of professional engineering.

From there I assembled and soldered all of the components, and programmed the Arduino Uno to respond to a controller's inputs and auto-level the quadcopter.

On August 9th, 2021, the Intergovernmental Panel on Climate Change (IPCC) released the first part of their sixth assessment of the climate crisis. The report highlighted how human activity has increased the global average surface temperature by 1.50 degrees celsius since 1850. The report's central conclusion to limiting future human-induced global warming is to limit cumulative carbon dioxide emmisions. This is because scientists have found a near-linear link between cumulative anthropogenic carbon dioxide emissions and the global warming they cause.

The objective of this project was to design and build a web application that allows users to track their carbon dioxide emissions for increased self-awareness of personal emmisions and incentivize lifestyle changes to limit global warming. The project, named GreenFoot, must allow users to track their carbon footprint, input how far they travelled & by what method to calculate carbon dioxide emissions, and add friends to compare weekly carbon dioxide emissions. GreenFoot was built using a MySQL database, Django (Python) backend, and a HTML, CSS & JavaScript frontend.

This project was submitted as a final capstone project in the Harvard University’s CS50 Web Programming Course with Python and JavaScript. The requirements from the course were that the project be an original, complex web application that uses an SQL Database, Django (Python) back-end, JavaScript front-end, and be mobile responsive.