Produce Bagging Aid

For this project, we chose to work on designing a solution for people with more chronic mobility limitations as our target users. To learn more about our users experience with shopping, we interviewed grocery store workers and learned that “The sound of a bag…will move [their] attention…to anticipate” that a customer needs help, and that on average, “Shoppers ask for help once a day”. These insights proved to us the prevalence of this challenge, at least on a local level. Further, from secondary research, chronic mobility limitations (most salient being Osteoarthritis) impact almost 1/4 of adults in the US. While these limitations can and often do impact shoppers daily experience, we also learned from grocery store employees that employees “don’t want to overstep their bounds” and feel uncomfortable stepping in to assist users as they don’t want to undermine their autonomy. Our challenge was to develop a solution to assist users with mobility limitations in opening produce bags at the grocery store in a discrete and autonomous way. From our user research (as well as a thorough review of secondary literature and state of the art solutions and patents), we developed our user specifications as shown in the table above. The orange box highlights our top 3 specifications most critical to optimize for meeting user needs. The quantification metric enabled us to derive tests to conduct in our prototyping phase to evaluate our success in meeting each user specification.

This table outlines all of the different performance metrics we needed to hone based on user specifications and what test we would conduct to evaluate our success in prototyping these abilities. After running through several ‘works-like’ prototypes to optimize different aspects of our design following the testing plan above, we created a more finalized prototype using a ratcheting clamp, as shown above on the right. This design was used to test with potential users to gain feedback before creating our final design.

We brought our product to a local CVS and tested it using produce bags as well as plastic shopping bags. We also invited a few peers to use our product while shopping. Overall, our feedback was positive, however, students raised concerns over the force required to close the clamp and the difficulty in opening the clamp. As our product is aimed at improving the shopping experience for individuals with limited mobility, having a high force threshold for operation defeated its use. Additionally, the long base board we included was to ensure the device stayed level and horizontal during use without a user having to hold it in place. This greatly increased the size of the product, however, and students commented that having such a large device made it awkward and clunky to bring with them. Because of this feedback and our own assessment of the device’s function, we iterated our final design, first developing a CAD model in SOLIDWORKS. Our final concepts focused on a thin, light model that was easy to slip into a personal bag or even to hold by hand. However, the design also had to be easy to install and keep itself stationary and horizontal during use. Lastly, it had to be easy to use (both physically and conceptually), so different closing mechanisms were re-evaluated, and spring tensile strength was calculated to optimize efficacy while minimizing force required to close/open.

We then 3D printed our final CAD model (including 2 arms, along with a central hub and axel. Then, we attached both arms to the fixture, one to the rotating axel and one to a stationary base plate and inserted a spring between them. Lastly we added adhesive pads to the end of each arm and fixture hooks to the back of one of the arms. Each arm included a hole in the bottom to insert an aluminum rod into. This rod allowed us to use lightweight material for the arms while ensuring they were reinforced to prevent breakage from pressure. In addition, we also spent time iterating the adhesion method used to attach a bag to our device, prototyping different methods such as pneumatic suction, clamps, and different types of adhesives. We determined pneumatic suction would allow our device to work on a wider array of bag materials (such as paper, thicker plastic, or fabric), however would increase the cost, weight, and energy required to operate. From our adhesive test, we tested several different types on metrics such as reusability, durability, and total weight it can hold, and we settled on the best performing option, an adhesive that if it wears down and you rinse it in water, it becomes re-activated when it dries.

Here is our product name and logo I created: the Personal, Helpful Bag Opener and Holder), which features a paper bag as our final project goal was to have versatile use with many different types of bags. I drew up designs for both plastic bags and fabric bags as well. In addition to the production-based insights I gained, I also learned a lot about the impact team dynamics has on the success of a design project. My team had a lot of very confident members, which was helpful for interacting with users and peers, but posed challenges when collaborating on proposed solutions and testing protocols. For different reasons, the team dynamics were never able to recover, and the work became very disjointed. While unfortunate, this experience was valuable in showing me how important it is to cultivate a collaborative, respectful team environment to support in-depth, authentic design work.