Shop Drop Roll LLC

TEDx Talk by Caitrin Lynch featuring the story of Shop Drop Roll.

Shop Drop Roll LLC is a provisionally patented attachment for manual wheelchairs that simplifies the transport and accessibility of goods. We have received awards from the Babson BETA Challenge and Northeast ARC Foundation ($2,500 each) and were featured in Caitrin Lynch's TEDx talk on design thinking. The device was initially designed during "Engineering for Humanity," a class where students design a working prototype with and for an older adult to help improve an aspect of their life. Our four person team worked directly with Terri, an older woman who uses a wheelchair, deriving our design from interactions with her. Shop Drop Roll enables the user to load bags on the device, detach it from their wheelchair, and turn around to access their groceries, making it easier to go shopping and carry belongings. Working with three other teammates, this project gave me the opportunity to do fieldwork with users, implement design thinking and practices, create patent drawings and designs in Solidworks, and conduct pilot testing of our prototype.

Concept Discovery

Before we started designing for Terri we visited her home several times and went grocery shopping with her to observe and develop ideas for potential areas of opportunity. We learned that Terri places extreme value in living as independent a life as possible, and will do whatever it takes to get out of the house more often and escape "cabin fever." Grocery shopping is one outlet for this, but due to the challenge of leaving the house often she was forced to only go once or twice a month and buy a large number of groceries each time.

After shopping in an electric scooter, Terri and the bagger fill two large cooler bags on her chair. One sits on the back of her wheelchair and the other in her lap alongside a six pack of paper towels. Terri then waits thirty minutes to an hour for a wheelchair accessible bus to pick her up. While our team also explored ideas related to cooking and getting into bed, brainstorming and creating low-fidelity, cardboard sketch models, but we were ultimately convinced that we could make her grocery shopping experience less taxing and enable her to be more independent.

Our initial ideation process lead to sketching and designing cabinet attachments for the back of her chair that would help Terri sort and carry a large number of groceries. As we began designing, we realized we were designing for the wrong problem. Rather than designing something that can help Terri buy a large number of groceries, we realized by connecting our design back to Terri's desire for a more social, independent lifestyle that we should design a product that can help her go shopping more often rather than enabling her giant shopping trips. This would reduce the need to buy a large number of groceries on each trip. Our new approach to the project helped us to develop the initial concept for Shop Drop Roll.

Rapid Prototyping

We decided to test the idea quickly before moving forward. We built a cardboard frame that we could hold up to Terri's wheelchair to get an idea for how it would look and feel. We brought Terri into the classroom to validate the idea and the interaction with the lever arm that disconnects the device from the chair. Still fixated on carrying heavy items, we wanted the frame to hold four large bags of groceries. We did another quick test by loading and stacking shopping bags and immediately realized that four bags would not be feasible, settling for two. At this moment we learned the importance of testing your ideas rapidly in the real world in order to validate them.

From there, we built a functional prototype that we had Terri test in the grocery store. We observed as the baggers struggled to understand where to place the bags, and we watched as Terri struggled to unload the heavy groceries from her chair. We had Terri take the device home and tested the process of unloading groceries into the refrigerator. Terri unlooped one of the two straps on her bag from the hooks, making it easy to put items into the fridge. Observing Terri helped us to discover some of the greatest features of the device we had designed and recognize where we needed to make changes.

Product Design Decisions

We designed Shop Drop Roll as a free standing frame that rests on the "deployment bar" attachment that mounts to the wheelchair handles. We designed the device in Solidworks with a sketch of the key mounting points on Terri's wheelchair. Central to the deployment of the frame is a slot and pin mechanism. The deployment bar pivots within the handle mounts, and pushing the lever slides the pin out of the slot, allowing the bar to rotate down and release the frame. We tested multiple materials for the pin and slot. We initially used a metal slot and plastic pin, which lead to snapping, and ultimately swapped the materials for a longer-lasting mechanism.

Beyond the Classroom

Terri now uses our prototype every time she goes grocery shopping, buying less food in one trip and going out of the house more often. Rather than waiting for the bus with bags in her lap, Terri can now explore nearby clothing stores after getting her groceries. She even used our product to carry her eighty pounds of luggage on vacation. We used our funding to hold a booth at the 2018 Boston Abilities Expo and garnered interest in the product and a set of early stage pilot testers to help us bring the product to other wheelchair users.