Most robot limbs aren't exactly kind to the organic world given all that unforgiving metal, and even rubber-based soft robots aren't very gentle. However, MIT has a better way. It recently built a hydrogel-based soft robot hand that's bio-friendly while remaining tough enough to withstand heavy use. The trick was to use 3D printing and laser cutting to weave hydrogel "recipes" into robotic structures, and pump water into those structures to make them curl or stretch. The results are mostly water-based fingers that still have the strength, durability and speed of more conventional robots.
To prove that the breakthrough works, the team devised an unusual experiment: namely, catch-and-release fishing. The gel-based hand could quickly close around a fish without hurting it, and let it go just as easily. The underwater test also showed that a hydrogel robot takes on the visual and acoustic properties of its environment, helping it blend in where virtually any other bot would stand out.
Of course, the technology isn't going to be limited to fishing expeditions. MIT envisions it being a tremendous help for surgical robots that could poke around in your body without the risk of damaging your organs and tissues. Researchers will still need to spend a lot of time refining and customizing their robotics to make that happen, but there could well be a time when robots can take over even the most delicate operations.