Durable Microstructured Surfaces: Combining Electrical Conductivity with Superoleophobicity

Abstract

In this study, electrically conductive and superoleophobic polydimethylsiloxane (PDMS) has been fabricated through embedding Ag flakes (SFs) and Ag nanowires (SNWs) into microstructures of the trichloroperfluorooctylsilane (FDTS)-blended PDMS elastomer. Microstructured PDMS surfaces became conductive at the percolation surface coverage of 3.0 × 10(-2) mg/mm(2) for SFs; the highest conductivity was 1.12 × 10(5) S/m at the SFs surface coverage of 6.0 × 10(-2) mg/mm(2). A significant improvement of the conductivity (increased 3 times at the SNWs fraction of 11%) was achieved by using SNWs to replace some SFs because of the conductive pathways from the formed SNWs networks and its connections with SFs. These conductive fillers bonded strongly with microstructured FDTS-blended PDMS and retained surface properties under the sliding preload of 8.0 N. Stretching tests indicated that the resistance increased with the increasing strains and returned to its original state when the strain was released, showing highly stretchable and reversible electrical properties. Compared with SFs embedded surfaces, the resistances of SFs/SNWs embedded surfaces were less dependent on the strain because of bridging effect of SNWs. The superoleophobicity was achieved by the synergetic effect of surface modification through blending FDTS and the microstructures transferred from sand papers. The research findings demonstrate a simple approach to make the insulating elastomer to have the desired surface oleophobicity and electrical conductivity and help meet the needs for the development of conductive devices with microstructures and multifunctional properties.

Amalgamation‐Assisted Control of Profile of Liquid Metal for the Fabrication of Microfluidic Mixer and Wearable Pressure Sensor

“…The EGaIn was selected as the conducting material due to its high electrical conductivity, low viscosity, and nontoxicity. [ 34,35 ] The choice of iron particles was projected to improve the conductivity of the elastomer, which has been verified in our previous works. [ 36,37 ] During mixing, EGaIn is broken into microdroplets and embedded between adjacent iron particle chains.…”

Synergetic Combination of Interfacial Engineering and Shape-Changing Modulation for Biomimetic Soft Robotic Devices

“…46 Guided by this simple concept, our group started our biomimetic research via the fabrication of surface micropillar structures of polymer (Figure 6a) 47 and investigated their contact behaviors with liquids and solids with the aim of establishing a relationship between surface structures and interfacial properties (Figure 6b−f). [48][49][50][51]54,58 In the following section, we describe two key aspects of our recent research activities on bioinspired interfacial Bioinspired Superhydrophobic Surface with Additives for Multifunctionality. Superhydrophobic surfaces refer to surfaces where the static contact angle for water is >150°.…”

“…The relations of stretchability and reversibility were characterized, showing that the Ag flake/Ag nanowireembedded microsurface has better mechanical and electrical performances. 48 Bioinspired Friction, Adhesion, and Dry Adhesives. Friction is the surface resistance of an object to its lateral movement over another surface, and adhesion is the state at which two dissimilar surfaces stick to one another.…”

A silver self‐assembled monolayer‐decorated polydimethylsiloxane flexible substrate for in situ SERS detection of low‐abundance molecules

“…Recent studies have shown that polydimethylsiloxane (PDMS) is a soft stamp template with unique advantages in the implementation of nanostructure self-assembly. [28][29][30][31][32] PDMS is transparent with low background Raman scattering. It has high light transmittance, good formability, etc.…”