US scientists have developed a novel soft, flexible and customisable sampling device that can help in the collection of different types of organisms from the sea without harming them.

The “soft gripper” device that has two to five “fingers” made of polyurethane and other squishy materials that open and close via a low-pressure hydraulic pump system that uses seawater to drive their movement.

Studying the underwater marine organisms required specialised equipment mounted on a remotely operated vehicle (ROV), as any other type of equipment could crack under pressure.

“Many of the animals we encounter in the deep-sea are new species and these soft robots allow us to delicately interact and study a more diverse suite of fauna,” said David Gruber, Professor at the City University of New York.

The grippers were attached to a wooden ball that was held and manipulated using ROV’s, hard claw-like tools, controlled by a human operator on the ship to which the ROV was tethered.

In the study, published in the journal PLOS ONE, the team put the latest version of their soft grippers to the test on a voyage aboard R/V Falkor in the remote Phoenix Islands Protected Area in the South Pacific.

The soft grippers were able to collect sea slugs, corals, sponges, and other marine life much more effectively and with less damage than traditional underwater sampling tools.

Based on input from the ROV operators, the team 3D-printed “fingernail” extensions that could be added to the gripper’s fingers to help them get underneath samples that were sitting on hard surfaces.

A flexible mesh was also added to each finger to help keep samples contained within the fingers’ grip.

Another, two-fingered version of the grippers was also created based on ROV pilots’ familiarity with controlling existing two-fingered graspers, and their request that the two fingers be able to hold samples with both a “pinch” grasp (for small objects) and a “power” grasp (for large objects).