Engineers repurpose measuring tape as robotic gripper

Inspired by the familiar childhood game of unspooling tape to see how far it could extend before bending, the researchers reimagined the material as a cost-effective, flexible, and safe alternative for robotic manipulation – particularly in agricultural settings.

The design, dubbed GRIP-tape – short for Grasping and Rolling In-Plane – was published in Science Advances on 9th April 2025. The team’s approach rethinks traditional robotic grippers, which are often bulky due to the added mechanisms required to deploy their appendages.

By contrast, GRIP-tape uses the inherent properties of measuring tape: its combination of flexibility and strength, its ability to retract into a compact space, and its capacity to extend over a distance. Each gripper consists of two ‘fingers’, formed from twin spools of measuring tape bonded together. These fingers are shaped into triangular sections and controlled by four motors each, allowing independent movement, extension, and retraction.

Senior Author Nick Gravish, a Faculty Member in UC San Diego’s Department of Mechanical and Aerospace Engineering, explained the rationale behind the design: “We like to look for non-traditional, non-intuitive robot mechanisms. The tape measure is such a wonderful structure because of its combined softness and stiffness together.”

The material itself – thin spring steel – proved ideal for handling delicate produce. It is soft enough not to bruise items like tomatoes or lemons, yet sturdy enough to hold its shape and support heavier loads. Early tests demonstrated that the GRIP-tape gripper could easily lift large fruits, such as fresh lemons and oranges, and could accommodate objects of various shapes and stiffness. The tape surface doubled as a conveyor belt, allowing objects to be rotated, transported, and deposited into containers.

Beyond its immediate application in agriculture, the team believes future versions of the gripper could be enhanced with sensors and AI to enable autonomous operation.

This work formed part of a broader National Science Foundation-funded effort to investigate soft robotic materials that bend while maintaining structural integrity.