Jose Berengueres

Compliant Distributed Magnetic Adhesion Device for Wall Climbing

We introduce a distributed compliant device inspired in gecko foot. It consists of a holder and small independent adhesion units on a flexible support. Unlike gecko, that uses Van der Waals force to achieve adhesion, the proposed design can be based on other adhesion phenomena, (for example magnetic or electrostatic force). We evaluate an implementation based on magnets. Key features are: limited surface roughness compliance, efficiency and cost-performance.

Structural properties of a scaled gecko foot-hair.

Experimental measurements on a cm-scale replica structure of a gecko foot-hair where magnets are used in place of (the usual) van der Waals force are reported. We conduct naked-eye experiments and investigate the mechanical properties of such hair structure and shapes that constitute it. Links between shapes and mechanical properties (functions) useful in geckos for clinging onto walls and adhering to rough surfaces are explained in terms of energy efficiency.

Gecko inspired Electrostatic Chuck

We introduce a climbing system, inspired by gecko foot that uses Electrostatic Chuck (ESC) in place of Van der Waals interaction. Electrostatic chucks are currently used in wafer foundries to pick-up and move delicate thin semiconductor wafers. The properties of ESC make it an interesting adhesion force for wall mobility applications. However the great dependency of current ESCs adhesion force on the surface roughness of the substrate renders them ineffective in normal-roughness walls. By combining ESC adhesion with geckos foot-hair surface-roughness adaptability function we propose a device for wall mobility applications.

Magnetic Hair for Wall Mobility

We introduce a climbing system, inspired by gecko foot that uses magnets in place of Van der Waals interaction. This is possible because both forces, except for a scale factor, have similar force-curves. Taking advantage of this fact, we manufactured a hand-size magnetic version of a gecko-foot. This allowed us to conduct naked-eye experiments. As a result we identify four shape function relations that might partially explain the design of gecko feet. Additionally, we report experimental data, introduce a quantitative concept to compare climbing systems and show a prototype of magnetic hair

On the Form and Function of Gecko foot-hair for Wall Mobility (video background)

In this videopaper, we introduce a climbing system inspired by gecko foot that uses magnets instead of Van der Waals interaction to achieve controlled adhesion.

A surface definition method for an interfacial energy database

Agreeing on a method to identify interfaces is a desirable step in order to build a database of interfacial energy. So far, the expression Sigma X Interface has been used to identify interfaces. Unfortunately, this conventional method cannot express arbitrary interface geometries. In the present work, we review interface geometries and propose a systematic Orientation Method based purely on geometrical considerations that can express arbitrary twists and slipping of interfaces.