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.
The Roost smart battery goes into your existing smoke detector and alerts you via your phone when your smoke alarm activates. It also gives you one-touch access to important emergency numbers (police, fire and so on) and notifies you weeks before the battery is low to avoid the chirping.