| Jul 16, 2025 |
Gecko-inspired dry adhesive adapts to angled surfaces with nanotech design
Researchers develop a nanostructured dry adhesive with a rotating core that grips strongly on misaligned surfaces, improving robotic and precision handling tasks.
(Nanowerk News) A team from Xi’an Jiaotong University has created a new type of dry adhesive that mimics the structure of a gecko’s foot to maintain a strong grip—even when surfaces don’t line up perfectly. Published in Engineering ("Self-Adaptive Core-Shell Dry Adhesive with a “Live Core” for High-Strength Adhesion under Non-Parallel Contact"), the study presents a self-adaptive adhesive that uses nanostructured contact tips and a rotating internal “live core” to overcome a major limitation in current adhesive technologies.
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Dry adhesives that rely on van der Waals forces can offer precise, residue-free gripping, making them ideal for robotics and electronics handling. However, these adhesives typically work best when two surfaces meet in perfect alignment. In practice, small angular mismatches can drastically weaken the grip, limiting their usefulness.
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The researchers tackled this problem by taking inspiration from how geckos use soft muscles and movable bones in their feet to adapt to sloped or uneven surfaces. Their design includes two key elements: a surface layer of mushroom-shaped micro-pillars, and a layered base with a rigid insert that can pivot inside a soft material, similar to a joint.
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These micro-pillars are just microns in size, with surface roughness at the nanometer scale. Such fine details allow the adhesive to make close contact with surfaces at the molecular level, maximizing the grip provided by van der Waals forces. The live core, embedded in a soft silicone shell, rotates in response to angled surfaces, helping the adhesive adjust its orientation and evenly distribute stress.
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| Design strategy of the self-adaptive core–shell adhesives. (a) The entire structure and cross section of the macroscopic core-shell adhesives; (b) The section morphology of the core-shell adhesives; (c) A brief description of the mechanism of the core-shell adhesives; (d) The adhesion performance of the core-shell adhesives under misalignment situation (2°); (e) Demonstration of the self-adaptation and anti-overturning property of the core-shell adhesives. (Image: Duorui Wang et al.)
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The adhesive was made from polydimethylsiloxane (PDMS) and silicone rubber, materials common in soft robotics. Tests showed that under non-parallel contact conditions, the new design delivered adhesion up to 100 times stronger than conventional adhesives made from a single material. It also resisted twisting forces that often cause objects to detach or slip.
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Computer modeling helped explain how the internal rigid core improves grip. As the adhesive presses onto a sloped surface, the core pivots slightly to bring the contact layer into better alignment. This minimizes localized stress points and delays peeling, improving stability. The adhesive’s performance held up across a range of temperatures and in humid or wet environments, which are typically challenging for dry adhesives.
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The team further optimized the structure by studying how material stiffness, core placement, and geometry affected the rotation and adhesion force. Their results suggest that the combination of nanoscale surface engineering and smart mechanical design enables an unusually robust and adaptable adhesive.
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The researchers demonstrated the adhesive’s capabilities by mounting it on a robotic arm and using it to grip a slanted optical lens—an example of a task where precise handling and sloped contact surfaces are unavoidable.
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This work shows how nanoscale features, combined with a mechanically responsive structure, can solve one of the key barriers to using dry adhesives in practical settings. The adhesive’s ability to handle misalignment, resist overturning, and function in difficult environments could support applications ranging from robotic gripping systems to the assembly of delicate optical components.
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