WHILL is a next generation personal mobility Wheelchair Transformer
Whill Team has created the WHILL, a device that can clamp onto the wheels of an existing manual wheelchair and to power it with electricity...
https://www.spicytec.com/2011/12/whill-is-next-generation-personal.html
Whill Team has created the WHILL, a device that can clamp onto the wheels of an existing manual wheelchair and to power it with electricity. Each circular “hub” contains a 24-volt motor, powered by a lithium-ion battery pack. The battery reportedly takes two hours to charge, offering a range of approximately 30 kilometers with a speed that may get up to 20 km/h. When needing to change the directions or adjust the speed, the users can easily accomplish those tasks via an operation of the curved control section that connects two “hubs”.