Project Development

What is our chemical device?

The issue

The recent Covid-19 pandemic has caused public places to be unsafe. Covid-19 has caused many airborne viral transmissions in public places and between people. It can also stay on surfaces such as door handles, train handles for days or weeks which can harm people. Since there is a lack of sanitizers for door handles, we decided to create a door handle sanitizer for public places.

What is the objective?

Our door handle sanitizer can sanitizer door handle after someone uses it. When the door is returning to its position it is able to turn on the UV lights and sanitize if before someone else uses it. This will help reduce the spread of Covid-19 and other harmful infectious diseases in public areas.

Here is a sketch of our design:

Team planning, Allocation, and Execution:

List of members:

Chief Executive Officer - Joshua

Was in charge of Programming

Chief Operating Officer - Edmund

Was in charge of CAD design, laser cutting, 3D printing, and piecing

Chief Security Officer - Ambrose

Was in charge of doing the PowerPoint slides and other documents (BOM, Gantt Chart)

List of materials needed:

Planning:

Actual Execution:

Design and Building Process:

Part 1: Fusion 360 design of sanitizer (Done by Edmund)

Part 2: 3D print out the design (Done by Edmund)

Part 3: Arduino Programming (Done by Joshua)

Part 4: Build the prototype (Done by Edmund)

CAD final Design of Door handle Sanitizer:

Videos of 3D printing the top:

Videos of 3D printing the bottom:

Here is how I created the 3D printed designs:

Initially, I wanted to design a normal door handle using Fusion 360 since it was cheaper to 3D. Here are the first few designs.

1st design:

I wanted to attach the sanitizer to the door handle but I had trouble attaching it.

2nd design:

3rd design:

I planned to attach the door handle separately to the sanitizer.

4th design:

5th latest design:

I wanted to go in-depth and explained how I made each of these but blogger.com is lagging for me and this blog will be very long.

Joshua created the programming which I will be showing in the blog.

We attached the products together and here is a picture of the finished product.

Here is Joshua's code:

Joshua's blog link:

Joshua's blog

Here is Ambrose's presentation slides:

ambrose presentation

Ambrose's blog link:

Problems and solutions

1st problem:

A problem that we encountered was the 4th design that I printed. We realized that the bottom support is weak and there isn't enough space for the door handle at the bottom. There was also a problem with the print as the inside has overfill and I didn't add support. To solve this I wanted more space in between the back of the door handle sanitizer and the front to fit the maker Uno board and breadboard.

To solve this, I created more space and split the design into 2 to reduce the print time, and added a plate on the bottom and top to attach them together using screws.

2nd problem:

A problem that we encountered with the last design was that the bottom print was actually a failed print at the base but that doesn't really affect our design as it's part of the aesthetic so we decided to use it since we don't have enough time to print another one.

3rd problem:

The holes for the backboard were not big enough so 1 solution that I can make is to cut out a bigger hole or use fusion360 and use a bigger backboard and put bigger holes for screws.

4th problem:

There wasn't enough space at the top for the maker Uno board to rest on easily so I could have made the top taller.

5th problem:

There wasn't a hole at the back for the cable to go through so it had to go through from the top which interfered with our cover.

6th problem:

The breadboard and the sensor were resting on nothing so we had to tape it to the back of the door handle sanitizer and it was hard to create a support for the breadboard and sensor to rest on.

Limitations:

Our group thought of the effectiveness of the design of the door handle sanitizer if it was implemented and we realised that it was only able to sanitize one part of the door handle making it ineffective so we thought of making the door handle rotatable and adding a locking function for the door handle so that it was able to pull the door handle up and rotate it using a servo motor and place it back down and lock it so it doesn't move around when a user uses it and also able to sanitize all sides of the door handle.

Project files:

Fusion 360 files:

Cura links:

Arduino Code: