Inflatable E-Bike Fits in a Backpack

Flexibility, portability, and intrinsic safety could make this personal mobility system better than rigid bikes and scooters

2 min read

Evan Ackerman is IEEE Spectrum’s robotics editor.

Photograph of a woman riding the Poimo (POrtable and Inflatable MObility) inflatable e-bike.
Photo: University of Tokyo

The trend toward communal sidewalk-based personal mobility systems (like shared bikes and scooters) has resulted in some amount of actual personal mobility, but also a lot of cluttered sidewalks, injured riders and pedestrians, and questionable business models. Fortunately, there are other solutions to the last-kilometer problem that are less dangerous and annoying, like this prototype for an inflatable e-bike under development at the University of Tokyo. From a package of folded-up fabric that fits in a backpack, Poimo (POrtable and Inflatable MObility) can be quickly inflated with a small pump into a comfortable and intrinsically safe mobility system that can be deflated again and packed away once you get where you’re going.

The body of Poimo is made of thermoplastic polyurethane (TPU). It’s easily customizable, and the researchers have experimented with other shapes, like mobile sofas, which we’re told would be ideal for relaxing at “waterfront resorts.”

It takes just over a minute to inflate Poimo to an optimal operating pressure (both stable and comfortable to sit on) to 40 or 50 kPa (6 or 7 psi), which is really not much at all. (Soccer balls are inflated to twice that pressure, so a small hand pump and some patience would be sufficient to get the e-bike up and running.)

The final step is to attach the rigid components, including the wheels, brushless motor, battery, and a wireless controller integrated into the handlebars. The total weight of all of that stuff is 5.5 kilograms (the inflated structure is just 2.3 kg), but the researchers tell us that they expect that the weight can be reduced; this is just a prototype.

Poimo was born out of a desire to leverage soft robotics techniques to create an intrinsically safe vehicle that minimizes the potential for injury or damage in the event of an accident, which is important for personal mobility systems that operate in spaces shared by pedestrians. Ryuma Niiyama, one of the authors of a recent paper presented (virtually) at the 2020 CHI Conference, told us that “we believe that our inflatable mobility, which is different from existing mobility systems and creates new relationships with people, will be useful as a one-mile mobility for the city in the future.” 

The researchers have tested Poimo a bit in Japan, where people have said that it’s more solid than they expected, it’s fun to ride, and that they want to use it with their children. Once past the prototype stage, Niiyama believes that Poimo can be much more cost effective than existing vehicles, even while remaining modular and easy to customize. From here, the plan is to continue optimizing the system for increased portability, lighter weight, comfort, and safety, with additional user studies to determine both social feasibility and pricing.

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