Self-Propelled Beach Wheelchair (9/23-8/24)

Team ShoreMobility was challenged with a project by Quality of Life Plus, a national organization dedicated to assisting disabled veterans, and AmpSurf, a nonprofit organization that provides adaptive surf therapy to individuals with disabilities. The team designed a self-propelling beach wheelchair that is controllable by a joystick. This chair will enable adaptive surfers to navigate the beach independently, providing them with greater independence. It is also designed to withstand wet and sandy terrains easily.

• In addition to the project description above, the team created a comprehensive list of media to support the presentation of the team's efforts for our capstone project. Below are the materials presented at Design Day by me and the team: the User Manual, Corrosion Chamber, and Design Day Video/Poster; other supporting documentation developed throughout the design process is also shown below.

• After conducting a finite element analysis (FEA) on the chair under a simulated load of 1000 lb, the resulting factor of safety (FOS) was 24

• The YouTube video and V&V chart also detail the completion of all system requirements set out by the team.

• To summarize project duties:

  Led a 4-person team of Mechanical Engineers that developed and delivered a Class 2 Medical Device: a self-propelled beach wheelchair capable of transporting adaptive surfers with paraplegia or quadriplegia to and from the beach shore safely.

• Managed project logistics such as: budget, team meetings, timeline, material procurement, vendor and stakeholder communication, an Integrated Master Schedule (Gantt Chart via TeamGantt), and Engineering Change Orders for compliance.

• Modeled and assembled the final system design of the all-terrain wheelchair in SolidWorks; conducted FEA to verify load-bearing capacity (300-1000 lb). Created the Final Bill of Materials in an engineering drawing following GD&TASME Y14.5.

• Integrated an NVIDIA Jetson Nano microcontroller with a ZED 2i stereo camera to enable semi-autonomous features (e.g, spatial mapping, object detection) to the chair via machine learning (PyTorch and Ultralytics YOLO). To enable obstacle avoidance in conjunction with the wheelchair’s motor controller (AC/DC connections), an emergency stop function was created. The chair is maneuverable via a joystick for use by adaptive surfers and also automatically stops to avoid any objects upon detection. ● Assisted with fabrication (welding) of chair and leg rest hardware made from 304 Stainless Steel (ASTM-A554 Mill Finish). Conducted validation and testing procedures to ensure compliance with safety and technical parameters outlined in the Preliminary Design Report(PDR); incorporated continuous stakeholder feedback throughout the design process. ● The final working prototype was received successfully by the sponsor (QL+) and industry at the Senior Design Day Expo in May; the wheelchair was delivered to the client(AmpSurf) in August(couldn’t be delivered earlier due to the client’s prior obligations). From May to August, I was responsible for maintaining equipment and ensuring the prototype retained all its working functions.

Design Day (Use Case) Video

Design Day Poster

User Manual

Final Design Exploded View

Verification and Validation

Corrosion Test Results (ASTM-B117)

Finite Element Analysis (FEA)

Design of Experiment (DOE)

Final Design (CAD; Physical Model)

Design Day Expo Setup

Corrosion Chamber (ASTM-B117)

Additional Projects

Below are additional projects I have worked on over the years, as well as ones I plan to continue working on in my spare time!

Coming late 2025 and updated through 2026: Spinal Motion

-currently working on developing various 3D-printed spinal orthoses for different users' anatomies, as well as a spinal motion tracking system (using an array of flex sensors) to track the movement of the spine in each case. I will start with my own measurements, then progress to outreach to help others.

-Software-wise, will use if and else if statements in conjunction with for loops to attain data in different ranges of motions resulting from data acquisition.

3D-Printed Allografts/Scaffolds

Conceptual Valve Assembly (8/21)

-Modeled an arm (blue), cover (green), housing (red), fasteners, and valve shaft (yellow) for a valve assembly capable of regulating adiabatic fluid flow with the rotation of the arm. Ran interference detection on the assembly to ensure block tolerance was nominal, and if any interference fits were present. Demonstrated understanding of assembly design, motion studies, and DFM.

Torsion Bar Design (4/23)

• Designed a conceptual torsion bar suspension system for a vehicle; selected hot rolled steel as my chosen material to meet specified design criteria, as well as exceed required factors of safety. To further ensure optimal durability of the torsion bar, an extensive stress and fatigue analysis was conducted on all relevant components (shaft splines, lugs, coupling, axle, and torsion bar).

3D-Printed Prosthetics

-The above is an AI photo of lower-limb prosthetics, I think, that illustrates my concept well. Similar to the insights that Spinal Motion will provide, I aim to help others not only with insight into one range of motion but also physically with a variety of them.

-Similar to how I have networked and collaborated with orthopedic surgeons on backtesting past cases at CTLS, I also want to potentially collaborate with prosthetics and orthotics centers to help those in need as 3D-printing comes into the fold in this field; my first prototype will be using my own measurements to present proof-of-concept.

-Using Materialise software: want to present proof-of-concept for potential scaffold use for point-of-care potential in hospitals to help with bone defect procedures.

-similar to my CTLS venture, will reach out to healthcare professionals for access to segmentation, and using Materialise software, will update this section with examples.

Spinal Motion

Anti-Tangle Earbud Case (5/19)

• Earlier in 2019, I also worked on a project similar to SoundScape: a 3D-printed enclosure that could untangle wired earbuds. Millions of people use earbuds, and they often get tangled, making this project an ideal one to work on. The final design was achieved by 3D printing an ABS material enclosure and incorporating a wooden gear on the inside to drive tension; an ideal mechanical advantage was also calculated with the gear's number of teeth.

• The gear was constructed from wood, rather than being 3D-printed, as the tolerances were not feasible for a 3D-printed gear. The tension mechanism works by using a lever to lock the gear, where rubber bands coil and uncoil, dependent on user input (work).

  - Post-processing was done on the 3D-printed ABS in the form of an acid bath (solvent bath) to help remove support and achieve a better finish on the resin material.

  • The case is versatile, being small and lightweight, and is capable of untangling the longest of earbuds (~20").