Tiny robots get micro-tentacles to handle delicate objects

A team of engineers has developed micro-tentacles for tiny robots, so that they can handle delicate objects. Lead author Jaeyoun (Jay) Kim from Iowa State University said that most robots use two fingers and, to pick things up, they have to squeeze them, but these tentacles wrap around the object very gently. The paper describes how the engineers fabricated microtubes just 8 millimeters long and less than a hundredth of an inch wide. The tubes are made from PDMS, a transparent elastomer that can be a liquid or a soft and rubbery solid.

The study also shows how the researchers sealed one end of the tube and pumped air in and out through it. The air pressure and the microtube's asymmetrical wall thickness create a circular bend. It further describes how they added a small lump of PDMS to the base of the tube to amplify the bend and create a two-turn spiraling, coiling action.

The engineers mention that spiraling tentacles are widely utilised in general for grabbing and squeezing objects. They also add that there have been continuous soft-robotic efforts to mimic them, but the life-like, multi-turn spiraling motion has been reproduced only by centimeter-scale tentacles so far. At millimeter and sub-millimeter scales, they could bend only up to a single turn.

Kim said the resulting microrobotic tentacle is "S-cubed - soft, safe and small," adding that it makes it ideal for medical applications because the microrobotic tentacles can't damage tissues or even blood vessels. The study is published in the journal Scientific Reports.