A5050754266- Adhesion, Friction, and Surface Interactions
- Advanced Sensor and Energy Harvesting Materials
- Force Microscopy Techniques and Applications
- Advanced materials and composites
- Tribology and Wear Analysis
- Diamond and Carbon-based Materials Research
- Metal and Thin Film Mechanics
- Lubricants and Their Additives
- Additive Manufacturing and 3D Printing Technologies
- Tendon Structure and Treatment
- Surface Modification and Superhydrophobicity
- Micro and Nano Robotics
- Tactile and Sensory Interactions
- Gear and Bearing Dynamics Analysis
- Nanofabrication and Lithography Techniques
- Silk-based biomaterials and applications
- Tribology and Lubrication Engineering
- Plant biochemistry and biosynthesis
- Mechanical and Thermal Properties Analysis
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Adipokines, Inflammation, and Metabolic Diseases
- Plant Surface Properties and Treatments
- Modular Robots and Swarm Intelligence
- Advanced ceramic materials synthesis
- Engineering Technology and Methodologies
Max Planck Institute for Intelligent Systems
2021-2023
Kookmin University
2023
Georgia Institute of Technology
2017-2021
Yonsei University
2011-2017
Google (United States)
2017
Government of the Republic of Korea
2016
A flexible pressure sensor with high performances is one of the promising candidates for achieving electronic skins (E‐skin) related to various applications such as wearable devices, health monitoring systems, and artificial robot arms. The sensitive response external mechanical stimulation fundamentally required develop E‐skin which imitates function human skin. performance capacitive sensors can be improved using morphologies structures occurring in nature. In this work, highly based on a...
Wireless soft-bodied robots at the millimeter scale allow traversing very confined unstructured terrains with minimal invasion and safely interacting surrounding environment. However, existing untethered soft millirobots still lack ability of climbing, reversible controlled surface adhesion, long-term retention on three-dimensional (3D) surfaces, limiting their use in biomedical environmental applications. Here, we report a fundamental peeling-and-loading mechanism to climb 3D surfaces by...
Fabrication strategies that pursue "simplicity" for the production process and "functionality" a device, in general, are mutually exclusive. Therefore, less expensive, equipment-intensive, consequently, more accessible to researchers realization of omnipresent electronics required. Here, this study presents conceptually different approach utilizes inartificial design surface roughness paper realize capacitive pressure sensor with high performance compared sensors produced using costly...
While a majority of wireless microrobots have shown multi-responsiveness to implement complex biomedical functions, their functional executions are strongly dependent on the range stimulus inputs, which curtails diversity. Furthermore, responsive functions coupled each other, results in overlap task operations. Here, 3D-printed multifunctional microrobot inspired by pollen grains with three hydrogel components is demonstrated: iron platinum (FePt) nanoparticle-embedded pentaerythritol...
Abstract The rapid growth in the miniaturized mechanical and electronic devices industry has created need for temporary attachment systems that can carry out pick‐and‐place transfer printing tasks fragile tiny parts. Current are limited by a fundamental trade‐off between adhesive strength state‐changing trigger force, which causes rapidly switchable adhesive. In this study, an elastomeric microstructure is presented combining trapezoidal‐prism‐shaped (TPS) mushroom‐shaped microstructure,...
Various functional complex 3D patterned surfaces with micro- or nanostructures have been developed and their superior performances over non-patterned smooth proven. However, it is challenging to mass-produce such micro-/nanopatterned surfaces, which limits commercialization drastically. Although roll-to-roll (R2R) manufacturing using flexible molds has implemented for mass-production of the poor mold repeatability issue not resolved yet. Here, a strategy significantly improve micropatterned...
Polytetrafluoroethylene (PTFE) coating is known as a low friction material that often used solid lubricant coating.
To date, a handful of different gecko-like adhesives inspired by spatula-shaped attachment hairs have been suggested based on wedge and flap geometry contact elements. However, while these surface designs shown to directionality in adhesion, high friction, long lifetime the ability work vacuum, an experimental verification very basic concept pulling angle effect has not yet reported. close this gap, here we use wall-shaped adhesive microstructures three heights systematically study normal...
Splitting a large contact area into finer, sub-contact areas is thought to result in higher adaptability rough surfaces, stronger adhesion, and more uniform stress distribution with tolerance defects. However, while it widely believed that splitting helps mitigate the negative effects of roughness on adhesion- friction-based attachment, no decisive experimental validation this hypothesis has been performed so far for thin-film-based adhesives. To end, we report behavior original split,...
Abstract Buds of horse-chestnut trees are covered with a viscous fluid, which remains sticky after long-term exposure to heat, frost, radiation, precipitation, deposition aerosols and particles, attacks by microbes arthropods. The present study demonstrates that the secretion does not dry out under arid conditions, melt at 50 °C, change significantly UV radiation or frost microscopic level. It is slightly swellable wet conditions; and, it universally wets adheres substrates having different...
Abstract Nanodiamonds (ND) present a unique combination of desirable mechanical, functional, and chemical characteristics that are ideally suited for reinforcing enhancing the wear resistance carbide based materials. Tungsten cobalt (WC-Co) matrix nanocomposites reinforced with varying amounts ND (2 – 10 vol.%) were synthesized here by spark plasma sintering. The rapid thermal consolidation route enabled attainment dense samples significant retention metastable diamond phase. NDs affected...
Although biomimetic technologies for dry reversible adhesion seem to be maturing, the costs, complexity, and time expenditures associated with current template-based molding techniques call research on other fabrication methods. In this paper, we report a novel cost-effective, simple, flexible drawing-based technique manufacturing soft elastomeric thin-film-based microstructures needed successful implementation of principles biological shear-activated adhesion. Several different types...
S. Kang et al. report a flexible and highly sensitive pressure sensor developed using deformable dielectric layer inspired by natural porous structures in article number 1600356. This exhibits an outstanding sensitivity, fast response, high stability. It is successfully integrated into array applied to fabricate real-time tactile sensing platform.
The frictional characteristics of ~62-μm diameter borosilicate glass balls used as rolling elements for a miniature electromagnetic linear actuator were assessed. placed between two silicon plates the with bearing tracks fabricated in shape V-grooves on surface. Rolling friction experiments conducted using well tribotester. It was shown that effective generating low coefficient ~0.01 over 11 million cycles under load 6.6 mN. For durability test tribotester, relatively high 245 mN applied. In...
Although surface chemistry is less important in dry adhesion than geometry, it may still prevent reliable attachment from being established shear-activated adhesives. However, some materials can be more universal others their adhesive interaction with random counterfaces. To identify a material that would preferable for use adhesives, here we studied the properties of polyurethane (PU) contact several substrates different chemical compositions. It was found pull-off and static friction...
The advancement of equipment technology is very important for winter sports competitions, but there has been a lack research on ice friction via the modification runner surface. In this study, we modify surfaces steel runners that are commonly used in to reduce by improving water repellency. A custom-built tribotester can measure high-speed conditions developed. Three surface treatment processes—vapor deposition, immersion, and spraying—are applied improve its hydrophobicity. results confirm...
In article number 1700368, Taeyoon Lee, and Wooyoung Shim, co-workers propose a fundamentally simple method of fabricating capacitor arrays, that can outperform their costly counterparts, manufactured via microfabrication. The array, made by ubiquitous activity from our daily lives, namely, writing on paper with pencil, is used as pressure sensor, which further integrated into fully functional touch device principle demonstration the concept omnipresent electronics.
Roll-To-Roll Manufacturing In article number 2207257, Metin Sitti and co-workers report a two-step curing-based roll-to-roll manufacturing process for the improvement of repeatability durability flexible silicone molds patterned with complicated adhesive microstructures against highly polyurethane acrylates. Using proposed process, mold demonstrates high up to 1000 cycles without significant degradation adhesion performance printed microstructures.