EC.721 | Spring 2009 | Undergraduate

Wheelchair Design in Developing Countries


This page includes descriptions of proposed projects, selected 2009 projects, and an archive of selected projects from prior years.

Project Objectives

Projects were defined in collaboration with our community partners. Each addresses a specific need and will greatly enhance the productivity and product quality of the workshops. These projects are not set in stone; new projects can be defined and the existing projects can be modified or combined. Ideally each project will have three to five students, but this is obviously dependent on enrollment. Funded fellowships offered through WDDC will allow students to implement these projects into the partners’ wheelchair workshops during the summer.

Community Partners

List of community partners and contact information

Proposed Projects

Students considered nine project proposals at the start of the term, ultimately selecting four to be developed.

Milestone Schedule

Week 2: Choose project teams

Week 3: Hold first lab meeting; contact team mentors and community partners; define functional requirements

Week 4: Strategy presentations due

Week 7: Concept presentations

Week 11: Most critical module (MCM) presentations

Week 14: Poster and presentation for MIT Museum

Week 15: Final presentation of project with a working prototype


Components list with prices, for Kenya, Tanzania, and Zambia: proj_complist.xls (XLS)

  • This file lists some available components with pricing for Kenya (bicycle, bearings, steel), Tanzania (bicycle), and Zambia (bicycle, bearings). Most steel components listed for Kenya are also available in Tanzania and Zambia; check with your partner contact if you have questions.

Material analysis of commonly available mild steel tubing sizes, proj_steel.xls (XLS)

2009 Projects


Tricycle Attachment

This project continued the work of the 2008 handcycle attachment team, making several essential refinements: simpler and faster to attach, lower in mass, lower cost, and improved aesthetics.

Power-assisted Tricycle (PDF)

This group worked with the Association of the Physically Disabled of Kenya (APDK) to add a power assist for heir tricycle wheelchair. The design would allow users who need to travel long distances to move more quickly and not have to rely soley upon their body power. The power assist might, for instance, help the trike user operate a delivery service.
Small Business/Education Wheelchair Attachments This team built on the work done during the 2008 class.
“Worldwide Mobility” Web-Based Donation Network This team built on the work done during the 2008 class.

Prior Project History

2009 was the third year of WDDC. The following projects were done in 2007 and 2008, and some formed the basis for 2009 projects.

Folding 3-Wheeled Wheelchair This project designed a new frame that will allow three-wheeled wheelchairs to fold small enough to be used on public transportation.

Handcycle Attachment

This project designed a handcycle attachment for a for standard 4-wheel wheelchair. This gives the owner the mobility advantages of a standard wheelchair in tight spaces, and adds the handcycle benefits to the chair — power and speed to cover long distances on very poor paths — after only a few movements.

Small Business Attachments for Wheelchairs

This project created a desk + storage attachment that helps its owner run a small business, such as phone card sales or repairing broken items, from their chair.

Web-Based Donation Network

This project designed a Web-based network that allows donors to fund the purchase of appropriately-designed wheelchairs for disabled people in developing countries. During the following summer, work continued on legal and financial issues involved in transferring money internationally, as well as a more complete implementation of the Web network.
Wheelchair Accessories for Women This project designed a device (a box attachment) for women to help them carry various objects around in a wheelchair.
2-speed tricycle drivetrain Students designed a 2-speed “figure-eight” drivetrain for hand-powered tricycles. The drivetrain works by combining a series of bicycle freewheels to obtain one speed by pedaling forwards and one by pedaling backwards, all without a derailleur.
Folding 3-wheeled wheelchair This project designed a folding system for 3-wheeled wheelchairs built in Africa. Enabling the chair to fold greatly increases how easily it can be transported on a bus or in the trunk of a taxi. The key of the team’s design is a novel joint/coupling that uses stacked angle iron to exactly constrain the front wheel to the frame. This design can be retrofitted onto any existing African-made 3-wheelers.
Improved tricycle frame This project designed a new tricycle frame that is stronger and lighter than currently produced frames. They analyzed available materials in Africa and generated a comparison of strength/weight, cost/weight, etc. to find the most appropriate tubing for use in mobility aids. Elements of their design were incorporated into the APDK 2-speed tricycle.
Marketing strategies The aim of this project was to improve marketing strategies of small wheelchair workshops. The team produced a logo and brochure for the KCMC wheelchair workshop, as well an info packet that informs wheelchair users about issues that may arise from a poorly fitted wheelchair. All of the materials have been translated into Swahili and printed in Tanzania. A student who continued this project as a summer fellowship also produced a manual that teaches people how to make and post a Web site from an internet cafe for free.

1. World-wide wheelchair donation network

The majority of wheelchairs used in developing countries are given away for free and break down quickly on rough terrain. Because users depend on handouts, they cannot assert economic pressure to improve imported products to suit their lifestyle. To address this problem the project team will create a Web-based network to connect donors from developed nations directly to workshops providing appropriate technology that meets user needs and suits the local environment. Through this system, workshops will advertise their clients, donors will select recipients, and workshops will provide confirmation of wheelchair delivery. A ll inputs and outputs will be controlled by workshops and donors, minimizing the need for an a separate institution to oversee this process and maximizing revenue flow to the manufacturers.

An additional component to the network will be a “Friendster” type peer-to-peer community where wheelchair manufacturers from around the world can share designs and ideas with each other.

2. Low-cost tricycle attachment for wheelchairs

In most developing countries, people with disabilities are not afforded the luxury of smooth roads, ramps, or handicapped accessible transportation. As a result, wheelchair users often rely solely on their own power for both long and short distance travel. Mobility aids currently used do not fully suit user needs; wheelchairs are exhausting to push on rough ground, while hand-powered tricycles, which are more efficient to propel, are too large to use in the house.

In this project students will continue development of a tricycle attachment that was developed in last year’s class. The attachment uses a vice grip to quicly attach to a wheelchair. The whole device costs approx. $50 U.S. The new design needs to be stowable somewhere on the chair. Additionally, a multi-speed drivetrain should be included on the device if possible.

3. Small business opportunities funded by micro loans Two of the major problems that affect third-world people with disabilities are the inability to afford a mobility aid and the lack of available jobs. This project will address both issues by identifying small business opportunities that can be run from the back of a wheelchair and/or tricycle and initiated via a micro loan. With this plan, disabled people will be able to buy a mobility aid and earn an income.
4. Power-assisted tricycle There are some tricycle users who wish to travel farther and faster than they could under their own power. The aim of this project will be to produce a powered tricycle that can be operated in a manual, power-assisted, or combination state (similar to a moped). The product will need to use locally-available components, be low-cost (~$300-$500US) and manufacturable at APDK in Kenya. One of the significant challenges of this project will be to devise a control system that allows the user to pedal, steel, and operate the engine.
5. Adjustable gear ratio for Kien Tuong tricycles The Kien Tuong workshop makes one of the coolest trikes in the world. By placing a steering wheel on top of the propulsion lever, a user can both power himself and steer at the same time. Kien Tuong wants to improve on this design by offering a tricycle with a variable gear ratio to accommodate different terrains. A simple way to do this is by changing one of the pivot points in the lever linkage. Whatever design that is developed should be simple, robust, and able to shift on the fly.
6. Flat-pack tricycle frame Many of our partner workshops would like to export their products to other countries. To do this efficiently, the tricycle frames should flatten so many can fit within a shipping container. Additionally, a collapsing frame would make transport on busses easier. The team that develops this project will produce a frame that folds flat (or can easily stack) and that can be modified for use in the varying tricycle designs produced by our partner workshops.
7. Marketing plan and grant writing guide Advertising of appropriate technology in developing countries can greatly increase product usage; for example, the revenues generated from the “Super Money Maker,” which is made by KickStart and advertised all around Sub-Saharan Africa, accounts for 0.6% of Kenya’s GDP. This project will include devising advertising material and strategies for selling wheelchairs and tricycles. Advertising materials may include brochures, websites, posters, and TV and radio advertisements. Additionally, this project will require the development of a grant writing guide to help wheelchair workshops identify and secure alternative means of funding.
8. Electrically-powered wheelchair/scooter A number of our partners have expressed a desire to carry powered mobility aids in their product line. The team that works on this project can choose to either create an electric wheelchair or an electric scooter similar to ones produced by “Clark.” The device that is developed will have to utilize batteries and motors that are cheap and available in the partners’ countries. This will require some creativity, as motors used in other applications (such as automotive, home appliance, etc) may work well for a wheelchair. The device will have to operate indoors, fit through doorways, and include a control system that is operated by the upper body.
9. Sports wheelchairs and tricycles Many workshops are reporting that their clients desire purely recreational devices. The team developing this project will have the choice of creating a new tricycle or wheelchair design. The tricycle should be a sport-commuter that is fun to ride. The wheelchair should be for basketball and/or tennis and conform to international competition standards.

Course Info

As Taught In
Spring 2009
Learning Resource Types
Demonstration Videos
Image Gallery
Lecture Notes
Projects with Examples