Conformably Skin-Adherent Piezoelectric Patch with Bioinspired Hierarchically Arrayed Microsuckers Enables Physical Energy Amplification

Abstract

An intimate contact interface between wearable energy harvesting devices and nonflat human surfaces is critical for harvesting energy from the body’s movements. The device can only absorb the deformation strain under stable interfacial adhesion to biological surfaces. Past developments have mainly examined the active layer of such devices, but the device/body adhesive interface effects are rarely considered. Here, we introduce a hierarchically arrayed octopus-inspired pattern (h-OP) formed on piezoelectric composite patch devices. The h-OP enables robust wet adhesion to skin because its dome-like architecture achieves interfacial adhesion by generating cohesive forces among liquid molecules. We used finite element method simulation to investigate decohesion behaviors with bending-induced stress distribution. The enhanced adhesion provided efficient energy generation under strain according to body movements. With 90° wrist bending, the h-OP devices demonstrated approximately triple the energy generation of implementations with no pattern, exhibiting stable adhesion and high energy generation efficiency, even on the wet skin.

Microtemplated Electrowetting for Fabrication of Shape‐Controllable Microdomes in Extruded Microsucker Arrays toward Octopus‐Inspired Dry/Wet Adhesion

“…The suction force enhanced by the liquid‐assisted effect of microdomes has been discussed in detail in previous investigations. [ 21,38 ] In the underwater adhesion process of EOMS (Figure S7, Supporting Information), most of the liquid was resisted between the microsucker tip surface and the foreign surface during the contact process. When the larger external preload was applied, the EOMS was compressed, and the liquid was squeezed out of the chamber as much as possible.…”

“…After removing the preload, the liquid molecules were accumulated in the upper part of the microsucker cavity, and the liquid‐assisted suction was generated with the structural recovery of EOMS. [ 38 ] Furthermore, the normal adhesion strength of the annular microhole arrays without microdomes in the underwater environment was the lowest, which was due to the lack of the liquid‐assisted adhesion enhancement generated by the microdomes. The adhesion behaviors under different preload (10–50 kPa) under both dry and underwater conditions are presented in Figure 4b,c.…”

Evolution of nanostructured skin patches towards multifunctional wearable platforms for biomedical applications

“…90 The efficiency of skin patches has been profoundly enhanced using nano-and micro-structured materials in the last few decades. 91 From the beginning of the nanotechnologydriven breakthrough in skin treatment, it was clear that basic requirements such as biocompatibility 92 and physical and chemical compatibility of the material with both body tissue 93 and possible bioactive molecules present in the developed biomaterials 94 should be fulfilled. Additionally, it is worth remembering that the skin is a vast organ, with various and very dynamic activities over time, which makes the development of materials with multiple properties such as the possibility to perform different functions and to control them by endogenous 95 or external stimuli necessary.…”

Bionic Structure Inspired by Tree Frogs to Enhance Damping Performance

“…Nature provides a wealth of inspiration for scientists studying the remarkable properties of biological surfaces. − The principles behind these biological surfaces have led to novel concepts and ideas for surface texture design. , For instance, the polygonal-shaped textures found on snakeskin reduce friction between the skin and the surroundings during rubbing locomotion . Inspired by this, polygon surface textures are often fabricated on thrust rings to enhance frictional properties .…”