Dataset Information

Micro-Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs.

ABSTRACT: Superior wet attachment and friction performance without the need of special external or preloaded normal force, similar to the tree frog's toe pad, is highly essential for biomedical engineering, wearable flexible electronics, etc. Although various pillar surfaces are proposed to enhance wet adhesion or friction, their mechanisms remain on micropillar arrays to extrude interfacial liquid via an external force. Here, two-level micropillar arrays with nanocavities on top are discovered on the toe pads of a tree frog, and they exhibit strong boundary friction ?20 times higher than dry and wet friction without the need of a special external or preloaded normal force. Microscale in situ observations show that the specific micro-nano hierarchical pillars in turn trigger three-level liquid adjusting phenomena, including two-level liquid self-splitting and liquid self-sucking effects. Under these effects, uniform nanometer-thick liquid bridges form spontaneously on all pillars to generate strong boundary friction, which can be ?2 times higher than for single-level pillar surfaces and ?3.5 times higher than for smooth surfaces. Finally, theoretical models of boundary friction in terms of self-splitting and self-sucking are built to reveal the importance of liquid behavior induced by micro-nano hierarchical structure.

SUBMITTER: Zhang L

PROVIDER: S-EPMC7578903 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Micro-Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs.

Zhang Liwen L Chen Huawei H Guo Yurun Y Wang Yan Y Jiang Yonggang Y Zhang Deyuan D Ma Liran L Luo Jianbin J Jiang Lei L

Advanced science (Weinheim, Baden-Wurttemberg, Germany) 20200809 20

Superior wet attachment and friction performance without the need of special external or preloaded normal force, similar to the tree frog's toe pad, is highly essential for biomedical engineering, wearable flexible electronics, etc. Although various pillar surfaces are proposed to enhance wet adhesion or friction, their mechanisms remain on micropillar arrays to extrude interfacial liquid via an external force. Here, two-level micropillar arrays with nanocavities on top are discovered on the toe ...[more]

PMID: 33101853

Similar Datasets

Project description:Currently, selective laser melting (SLM) has been thriving in implant dentistry for on-demand fabricating dental implants. Based on the coarse microtopography of SLM titanium surfaces, constructing nanostructure to form the hierarchical micro-nano topography is effective in enhancing osseointegration. Given that current nanomodification techniques of SLM implants, such as anodization and hydrothermal treatment, are facing the inadequacy in costly specific apparatus and reagents, there has been no recognized nanomodified SLM dental implants. The present study aimed to construct hierarchical micro-nano topography on self-made SLM dental implants by a simple and safe inorganic chemical oxidation, and to evaluate its contribution on osteoblastic cells bioactivity and osseointegration. The surface chemical and physical parameters were characterized by FE-SEM, EDS, profilometer, AFM, and contact angle meter. The alteration on bioactivity of MG-63 human osteoblastic cells were detected by qRT-PCR. Then the osseointegration was assessed by implanting implants on the femur condyle of New Zealand Rabbits. The hierarchical micro-nano topography was constituted by the microrough surface of SLM implants and nanoneedles (diameter: 20∼50 nm, height: 150∼250 nm), after nanomodifying SLM implants in 30% hydrogen peroxide and 30% hydrochloride acid (volume ratio 1:2.5) at room temperature for 36 h. Low chemical impurities content and high hydrophilicity were observed in the nanomodified group. Cell experiments on the nanomodified group showed higher expression of mitophagy related gene (PINK1, PARKIN, LC3B, and LAMP1) at 5 days and higher expression of osteogenesis related gene (Runx2 and OCN) at 14 days. In the early stage of bone formation, the nanomodified SLM implants demonstrated higher bone-to-implant contact. Intriguingly, the initial bone-to-implant contact of nanomodified SLM implants consisted of more mineralized bone with less immature osteoid. After the cessation of bone formation, the bone-to-implant contact of nanomodified SLM implants was equal to untreated SLM implants and marketable TixOs implants. The overall findings indicated that the inorganic chemical oxidized hierarchical micro-nano topography could enhance the bioactivity of osteoblastic cells, and consequently promote the peri-implant bone formation and mineralization of SLM dental implants. This study sheds some light on improvements in additive manufactured dental implants.

Dataset Information

Micro-Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs.

Publications

Micro-Nano Hierarchical Structure Enhanced Strong Wet Friction Surface Inspired by Tree Frogs.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets