Finding batteries powerful enough to fuel an exoskeleton's motorized joints remains a key stumbling block, explains Sugar.

CNN: Robot exoskeleton suits that could make us superhuman

At the sidewalk he stopped, put down his case next to the sugar maple, wiped his jacket sleeve across his forehead, and gazed up the block as if he were the new boy in school, getting ready to cross the school yard, where faces were already turning to stare at him.

NEWYORKER: Miracle Polish