Gripping device from Kiel University has microstructures on its surface that control adhesive forces with exposure to UV-light.


  • Tunable
  • Versatile
  • Gentle


  • Robotics
  • Manufacturing

UN Sustainable Development Goals Addressed

  • Goal 9: Industry Innovation & Infrastructure

The Challenge

In manufacturing processes, adhesives and metal gripping devices are often used to move product components into place. The adhesives are usually a single-use, strong glue that leaves a sticky residue once removed, and metal grippers can damage components. These maneuvering mechanisms are inefficient and increase waste generation within manufacturing processes.

Innovation Details

The photocontrollable gripping device is a UV light-sensitive multilayer tape. The top layer consists of mushroom-shaped pillars with flat tops that touch the surface of the target material. These pillars are embedded in polydimethylsiloxane, a silicon-based organic . In the absence of UV light, the top layer of the device is aligned and can therefore stick to a solid material. The second layer contains azobenzene liquid crystals, which are responsive to UV light. When UV light strikes the crystal layer, the device curls slightly, gently pulling the sticky first layer off of the surface, effectively releasing the material. The photocontrollable device does not leave any residue on materials and is less likely to damage products. Moreover, no heat is required to activate the adhesive.

Biomimicry Story

The device was inspired by gecko toes, which allow the reptiles to walk up flat surfaces, effortlessly sticking to materials and then readily unsticking when necessary. Gecko toe pads are covered in millions of small hairs called setae, which branch into nano-scale structures ending in tiny discs called spatulae. Essentially, these tiny hairs get so close to the contours of a material that electrons from the material’s molecules interact with the gecko hair molecules, creating an electromagnetic attraction. When approaching a surface, the gecko angles its satae such that the spatulae are flat and may engage, increasing the attractive force between the toe and the surface. Then, to detach, the gecko increases the angle of the satae, making it possible for the toe to peel away from the surface.