Nature inspired wet adhesive E-Skin patch for biosensing applications

Abstract

Tree frogs are able to climb or stick to wet and rough surfaces. The hexagonal epithelial cells enclosed by profound passages which shield the surface of each toe pad and the array of nano-pillars on their surface are the main reason for their outstanding reversible adhesion in wet and rough environment. Inspired by the frog toe pad hexagonal hierarchical micro-pillars are developed by using Silicon rubber/ZrO2 nanocomposite. Due to the addition of oxide nanoparticles wettability properties of the rubber enhanced. The interlocking structures and hexagonal pattern helps to improve the capillary action and the sweat/water particles are drained easily, as a result surface adhesion increases. To design the hexagonal micro-pillars innovative laser engraving technique is adopted. The homogeneous distribution of nanoparticles and hierarchical hexagonal micro-patterns are confirmed through SEM analysis. This innovative design approach is helpful to design E-skin adhesive wearable devices for accurate monitoring of physiological signals.