Novel Key Handles for Tuning the Adhesive Properties
Our work, which has been done in collaboration with Vittorio Saggiomo from the Bio-NanoTechnology group at Wageningen University, and Marleen Kamperman from Groningen University, shows that samples having 3D mushroom-shaped features have desirable mechanical functionality to adhere to soft and rough surfaces such as fabrics (Figure b) via mechanical interlocking. Although mechanical interlocking sounds like a simple process, and can occur annoyingly easily as a brief exposure to catchweed will surely confirm, there is a surprising level of microscopic dynamics occurring in the adhesion process itself. We have shown that attachment–detachment dynamics taking place at the interfaces can be experimentally accessed in great detail, revealing novel key handles for tuning the adhesive properties of soft patterned interfaces.
The main target of our work is indeed to reveal the fundamentals of patterned adhesion, with the overall aim of improving the adhesive strength of these interlocking-based adhesives. A fundamental understanding of mechanical adhesion and its scaling behaviour will perhaps allow us to understand other types of dry adhesives such as gecko adhesives, where the dynamics of an individual feature is hard to visualize due to the nanometric size of the features. Our work will certainly open up new routes towards active control and thus robotic optimization of mechanical adhesion, for example by embedding microfluidics or electromagnetic control features in the patterned adhesives. This work therefore naturally fits in the framework of the 4TU Soft Robotics initiative (https://dutchsoftrobotics.nl/), a collaborative Dutch research effort from the four technical universities in the Netherlands to develop enhanced soft robotics technology.
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