The ROW-BOT propels itself by converting water waste into electricity
The common colloquialism “what goes in, must come out” does not always apply to science. Various chemical or physical changes in substances may change what exact is “coming out.” Or at least this is certainly the case with the friendly little swimmer The Row-Bot. As the name so cleverly suggests this self-propelling robot eats up waste floating atop of the ocean water, converting the bacteria into usable energy, powering itself to continue swimming and eating up more waste.
If it sounds too good to be true then maybe you are just not thinking ambitious enough. Think of a the beloved suckerfish, who is paid homage by any aquarium lover.