Wet and Dry Adhesion Properties of Self‐Selective Nanowire Connectors

Abstract

Here, the wet and dry adhesion properties of hybrid Ge/parylene nanowire (NW) connectors are examined. The ability of the NW connectors to bind strongly even under lubricating conditions, such as mineral oil, sheds light on the dominant role of van der Waals interactions in the observed adhesion. The superhydrophobic surface of the NW connectors enables the wet, self‐cleaning of contaminant particles from the surface, similar to the lotus effect. In addition, the effect of NW length on the shear adhesion strength, repeated usability, and robustness of the connectors, all critical properties for applications that require reversible binding of components, is examined.

ZnO1–x Nanorod Arrays/ZnO Thin Film Bilayer Structure: From Homojunction Diode and High-Performance Memristor to Complementary 1D1R Application

“…The small surface fraction of the solid owing to the formation of the ZnO 1– x NRs leads to the increase of the larger surface fraction of the air pocket inside the ZnO 1– x NRs, eventually resulting in a larger CA to prevent the penetration of water molecules into the device. In addition, by increasing the aspect ratio via growing longer ZnO 1– x NRs, we are able to further increase the CA to >150°, which agrees with a report in the literature. − To evaluate the surface self-cleaning function, the endurance tests at a read bias of 0.1 V for both devices without and with coverage of a water droplet were measured as shown in Figure c and d (see Supporting Information for the detailed measurements). Consequently, the endurance test of the ZnO TF device was unstable, eventually resulting in a short circuit after ∼50 cycles (68th cycle).…”

Strong and Reversible Adhesion of Interlocked 3D-Microarchitectures

“…It is worth noting that the normal adhesion strength of 775 kPa is much higher than those of previously reported interlocking devices based on nanomaterials. For example, the normal adhesion strengths of the Ge/parylene hybrid nanowire-based adhesive or polymer nanofiber-based interlocking adhesive are negligibly small compared with their shear strengths [2,3,22]. In contrast to these nanostructure-based interlocking systems, our adhesive could provide strong adhesion strength in both the normal and shear directions.…”

“…It was noted that previous interlocking devices based on HAR, 1D nanomaterials did not possess such protruding tips or heads. Therefore, their interlocking adhesions were mostly dependent on the van der Waals interactions between the side walls of the interlocked structures, which resulted in limited adhesion performance, especially in the normal direction [2,3]. In contrast to the 1D nanostructure-based interlocking adhesives, our interlocking adhesives had unique 3D tip configurations.…”

A Review of the State of Dry Adhesives: Biomimetic Structures and the Alternative Designs They Inspire

“…Adding weight continuously via a liquid pump has the advantage of gradually increasing load at a steady rate, thus improving measurement precision. A number of researchers have chosen to characterize the shear strength of their fibrillar dry adhesives through either directly hanging weights [ 116 , 117 , 123 , 149 , 161 ], or by manual application of force using a spring scale for measurement [ 153 ]. A notable shortcoming of these methods is that only measurable quantity of relevance will be the force that occurs at the point of unstable interfacial failure.…”