Bio-inspired Interlocking Micro-Patterning for Tunable, Switchable and Selective Adhesion in Wet and Dusty Environments

<p>Abstract of the related article: Achieving adhesion under unfavourable conditions, such as when van der Waals interaction is not available or in dust environments, is crucial in applications ranging from surgical sutures to wound-healing tapes, underwater adhesives, robotic grippers, and space grasping.<br>Interestingly, plants, animals, and microorganisms living in such environmental conditions, show surface morphological traits optimised to achieve mechanical interlocking. Thus, they achieve an effective work of adhesion thanks to the interplay of friction and interfacially-storeable elastic energy, which otherwise typically suppress adhesion.<br>In this work, we provide the design and fabrication fundamentals for achieving tailorable, switchable and robust mechanical adhesion under a general environmental condition, such as wet or dusty, bio-mimicking natural solutions.<br>A theoretical framework for the design of mechanical adhesion, based on mean field continuum contact mechanics, is suggested, and validated experimentally. This study can pave the way for the development of new technologies, to be employed in situations where conventional adhesives may be ineffective, such as for surfaces exposed to water, solvent vapors, lubricants, high temperatures, dusty environments, high vacuum, or aerospace applications, or processes where switching and selective adhesion is needed such as grasping and sorting applications in semiconductor industry.</p> <p>The files are named after the numbering of the Figure in which they are used.<br>Description of the scripts as following:</p> <p>- FigureS5_ABCD.nb is a mathematica script to visualize the normalized single pair interaction for spherical interlockers, relating the dimensionless axial force to the dimensionless axial position.</p> <p>- Figure6_AnalyticalModel.nb is used to obtain the theoretical probability density function of the distance between microstructures when they follow a uniform distribution over a circular area.</p> <p>-Figure5.nb is a mathematica script used to perform a parametric study on double conical interlockers, varying the R/I_0 ratio, in approach/recede motion in dilute/dense conditions</p> <p>-Figure6_xyz_123.py is a python script used to perform Montecarlo simulations, it computes the histogram of distances between points randomly spread (lattice distributed, uniformly distributed, quasi-random distributed) on a unit circle.</p> <p>-FigureS8B.nb is a mathematica script used to average all the force contributions during the detachment phase of double conical patterned surfaces in order to get the Equation of state of the system, relating the normalized pressure to the out of plane axial displacement.</p> <p>- FigureS5_EFGH.nb is a mathematica script used to perform a parametric study on spherical interlockers, varying the friction coefficient value, in approach/recede motion in dilute/dense conditions.</p> <p>- Figure4.nb is a mathematica script used to perform a parametric study on spherical interlockers, varying the R/I_0 ratio in dilute/dense conditions.</p> <p>- FigureS6_EFGH.nb is a mathematica script used to perform a parametric study on double conical interlockers, varying the friction coefficient value, in approach/recede motion in dilute/dense conditions.</p> <p>- FigureS8A.nb is a mathematica script used to average all the force contributions during the attachment phase of double conical patterned surfaces in order to get the Equation of state of the system, relating the normalized pressure to the out of plane axial displacement.</p> <p>- FigureS2.rar is a folder with images of the dust characterization (coarse.tif; fine.tif; extrafine.tif) with python scripts to analyse the said images (ImageAnalysis.py) and extract the histogram of the equivalent particle diameter (HistogramPlot.py)</p> <p><br>- FigureS6_ABCD.nb is a mathematica script to visualize the normalized single pair interaction for double conical interlockers, relating the dimensionless axial force to the dimensionless axial position.</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p>