Ben Welter - Friday, September 28, 2018
A student’s creative take on wheelchair design has won a national competition in the United Kingdom.
Kristen Tapping, a product design student at London South Bank University, won the inaugural "Getting Back on Track" design competition held by the law firm Bolt Burdon Kemp. The contest challenged UK-based university students to design a product aimed at improving the lives of people with a spinal cord injury. The law firm awarded Tapping £3000; the university awarded an additional £2,000 (a total of about $6,500).
Tapping's lightweight wheelchair features a seating material enhanced with phase change material to ensure thermal comfort and a split wheel-to-rail system that eases movement through gear reduction and wider pushing surfaces. Tapping provided details on the concept in an email interview.
Q: How did you become interested in product design?
A: "I had worked a wide array of jobs from bartender to personal trainer to TV salesperson and decided a decade after getting my first degree to get into design, something I had always been interested in but wasn't sure I would be good at. I studied a year of interior design but stopped as I felt it was too limited for what I wanted. When I came across industrial/product design, the combination of conceptual design with hands on prototyping was a perfect fit and I dived right in. I am currently on placement in Spain designing automotive interiors for Grupo Antolin."
Q: Moveo's most ingenious feature appears be the propulsion system. Reverse propulsion is used in at least one wheelchair on the market (https://www.rowheels.com/product), but your concept separates the hand wheel from the ground wheel, using a spur gear to maximize force. What inspired you to pursue this approach? Is this configuration unique, as far as wheelchairs?
A: "This design challenge was specialized for people with spinal cord injuries which are quite different from others - on top of not being able to walk, many cases affect the upper body nerves leading to the inability to have dexterity and strength in the hands. With this in mind, it is exponentially harder for them to push a wheelchair rail as they cannot grab it. The other issue I noticed with all wheelchairs (that I have seen so far at least) is that the user touches the wheel when pushing the rail - I tested this myself by sitting in one and I could not push forward without coming into contact with the wheel. This is obviously not very pleasant or sanitary - would be the equivalent of a non-wheelchair user touching their hand to the base of their shoe after each step.
"The design started with the necessity for the wheel to be separate from the rail to avoid touching the wheel and give users a wider pushing surface in a material that has more inherent grip than metal (here I proposed Infinergy, a BASF/Adidas material that is made from recycled Adidas shoes). After consulting with some engineers, I made this happen through a simple spur gear mechanism where pushing the rail backwards would push the spur gear which would in turn propel the wheel forward. The pushing backwards to move forward simply came about from this spur gear mechanism, however it could be switched back to pushing forward to move forward by simply adding an additional gear. Ideally, the user would be able to manually switch back and forth between pushing forward and backwards to prevent muscle fatigue.
"As far as I know my configuration is unique in wheelchairs - I have only seen the rail being at the side of the wheel as in the standard design. As far as other products go, it follows a bicycle's basic spur gear mechanism."
Q: How did you become familiar with phase change material? Have you used it in other projects?
A: "I came across PCMs while interning at a materials firm and became really fascinated with the process they continually undergo. The reason I used them in this concept is because a less known side-effect of spinal cord injuries is the inability to self-control body temperature - the user's body may be extremely hot when it is cold out, and visa versa. I felt that using a PCM fabric on the seat would help bring down the overall body temperature to a more stable point. I have not used PCMs prior to this project however I am using it in a current concept regarding heat recovery. I am really interested to see where the technology will go - for example the recent university study that managed to activate PCM heat release with a light trigger."
Q: Can you provide details on the PCM fabric used in your design (salt hydrate/biobased/paraffin; peak melt point; energy storage capacity in joules per gram; manufacturer, etc.)?
A: "The fabric I proposed was Schoeller PCM 30092, which has a thermal storage capacity of 35,000 joules per square meter. Schoeller provides a variety of thicknesses which affect the energy storage capacity and padding/comfort level. While specifying a certain fabric would require prototyping and testing, I would suggest one with a composition of 37% polyurethane, 36% polyester and 27% paraffin."
Q: The energy storage capacity of PCM-coated fabric is much less than PCM encapsulated in flexible film. Did you consider using PCM cooling packs instead of PCM fabric?
A: "This option could be explored to see which would work best in this product. One benefit of the PCM-coated fabric is the ability to place it in the washer, something I had in mind for Moveo."
Q: What's next for the Moveo: patent application, prototypes, commercial development, etc.? Have any manufacturers expressed a commercial interest?
A: "While I doubt a patent application would be valid since this was a student competition and the details have already been made public through various publications, I would rather the concept be an inspiration to other wheelchair designers to address the wheel/rail issues stated above. Entering this competition, I wanted to design anything else than a wheelchair, but after being frustrated seeing horrible designs and how they affect the users' daily lives, I decided to give it a go. I did see an interesting student competition entry that uses handles and gears to move forward, but otherwise am disappointed with the lack of innovation from established manufacturers to solve the issue of users having to touch the wheel every time they push.
"I am currently on placement so sadly have no time at the moment to prototype it, however I may make it my final year project once back at LSBU. It would be great to partner with Cerebra to possibly make Moveo a real product, however a wheelchair needs lots of engineering and testing so partnering with an experienced manufacturer as well would make a great team."
Q: The prize includes £3,000 and the chance to undertake a week’s internship at the Cerebra research center. What do you plan to do with the cash award?
A: "London is quite an expensive city, especially on a full-time student budget, so the £3,000 will help me focus on school during my final year at LSBU. I may also go into prototyping for my final year project.
"I definitely plan on accepting the internship with Cerebra and have talks of squeezing it between the end of my current placement and before school starts. With Cerebra's assistance, I am looking forward to being able to develop other concepts that help people with disabilities and make them come to life using their workshop."
Q: Any idea what you'd like to focus on after graduation?
A: "Really not sure. I am as excited designing a futuristic car interior than I am an ergonomic toilet brush - I just really love design. One thing I do know is I want to design useful products that have a positive impact on people's everyday lives and do not degrade the environment during usage and at end of product life. With this project and having just won the Heatrae Sadia competition (hot water cylinders), I find myself being more and more interested in smart insulation and thermal storage solutions that work sustainably with zero or little energy. With our planet's diminishing resources and increasing temperature, solutions in this field will definitely be a necessity."