Abandoned pens and other such stationery stand a chance at purposeful usage, thanks to the Pen Printer. The device uses the ink from discarded pens to print on paper. The current tech may not support such an ambitious idea, but it’s worth the exploration, since many of us have bundles of uncapped and discarded pens in our drawers for no apparent reason.
Great design though for the average step and still quite risky for disabled or weaker members of society. Steps are too risky! I feel they should use suction pads and mechanise it like a slinky in effect.