ectoplasm

Via Super Punch, we discover that engineers at the Massachusetts Institute of Technology have created translucent amœboid robots composed almost solely of hydrogel—a rubbery substance that’s fairly robust, enabling these little gelatine machines to dart around quickly and punch quite above their weight with flagella and pseudopodia.
The video demonstration that includes enveloping and then releasing a fish is a little scary to imagine, given their near invisibility, but the potential is really staggering from cleaning up pollution in the oceans to making surgery a matter of swallowing a pill. Not only are the robots able to evade visual detection, appearing only as a ripple, they also have the same acoustic and fluid dynamic properties of the surrounding medium when relaxed and solid objects would pass through them without realising it—just a ghostly organising principle for water. It makes me think of the undersea aliens encountered in the 1989 James Cameron film The Abyss and wonder if such technological surrogates will be our ambassadors for first contact.