Package opening tool

design

Overview

My Role: Conducting user interviews, developing concepts, laser cutting and testing the initial prototypes, and assembling the final 3D printed version
Tools/Skills: User Interviews, User Testing, 3D Printing, Laser Cutting
Timeline: January - May 2017 (5 months)
Team: 4 (MechE)

Context

Burt, a local Boston community member, reached out to our Design for America team to help solve one of the challenges he was facing in his life. Burt’s image is obscured for privacy purposes.

Burt's background. Retired professor with doctorate in rehabilition. Power wheelchair user. Limited range of motion. Fine finger dexterity limitations (FFD).
Quotes. Virtually no grip strength with either hand. Cannot turn a small switch or pinch. Opening packages in impossible.

We found that Burt would gain a significant amount of independence if he was able to open packages by himself when he was not at home.

Goal

How can we design a pocket knife with FFD limitations in mind?

Outcomes

The final prototype was made using 3D printing and an existing curved Xacto blade. The following features were included to address Burt’s needs:

1) A slot was included in the body to make sure the blade would be covered when closed

2) A tab was added to allow the blade to be pushed out easily

3) The blade was hinged using a bolt with sufficient friction so that the blade would not fall out, but would also not require a lot of strength to release

4) A large hole for Burt’s finger was covered with gripping tape for comfort

The final prototype, which was given to Burt after a final design critique, is shown below.

Final 3D printed prototype in closed and open positions

Design Process

First, we observed how Burt opened packages at home, where he used a regular curved Xacto knife that he could brace against a surface and pull across a package if it was handed to him. We researched existing products that could either open or puncture bags, but none of them were suited for Burt as they required grip or were too small.

Existing technology. Easy glide bag opener. Snippit bag opener. Blade claw armor ring. None of these are easily usable by Burt.

Based on interviewing Burt and outlining the advantages and disadvantages of the existing products, we determined a list of design requirements for a portable device that Burt could use to open packages.

Design requirements. Safety first! Effective at opening packages. Easy to manipulate without fine finger dexterity. Lightweight. Must not look like a disability device.

Then, we created several prototypes using laser cut pieces and the same curved Xacto blade he was used to at home.

First prototypes. Goal: determine mechanism for blade release. Folding mechanism. Sliding mechanism. Four-bar linkage. Chosen: sliding or folding mechanism.

We user tested all of the prototypes with Burt to understand what attributes were important to him and which designs had those attributes.

Second prototypes. Goal: determine ease of use and Burt's style preferences. Burt testing folding design with curved blade. Liked: compactness, blade shape. Burt testing sliding design. Liked: sturdiness.

After synthesizing information from Burt, we came up with the final design.

Final Design. Folding mechanism with large tab lever to open blade. Large hole for grip. Curved blade.

Reflection

This project was eye-opening in several ways. First, I gained an appreciation for rapid prototyping and how it could be used to learn for the actual user we were designing with. By allowing Burt to use the quickly made prototypes, we were able to synthesize what aspects of each were important to him. For example, we were able to quickly see if he had trouble using some of the opening mechanisms. Second, although we created this design for a singular user, it did make us think about universal design more critically. For instance, even without limited FFD, a compact and simple device like this might be used more easily than a traditional pocket knife or letter opener. Overall, the project allowed me to really listen to Burt’s concerns and perspective to inform the design, which is critical when designing inclusively.