A5021030678- Adhesion, Friction, and Surface Interactions
- Surface Modification and Superhydrophobicity
- Advanced Sensor and Energy Harvesting Materials
- Advanced Materials and Mechanics
- 3D Printing in Biomedical Research
- Cellular Mechanics and Interactions
- Polymer Surface Interaction Studies
- Semiconductor materials and devices
- Advancements in Battery Materials
- Graphene research and applications
- Supercapacitor Materials and Fabrication
- Nanofabrication and Lithography Techniques
- Advanced Battery Materials and Technologies
- Electrohydrodynamics and Fluid Dynamics
- Conducting polymers and applications
- Tactile and Sensory Interactions
- Neuroscience and Neural Engineering
- Engineering Technology and Methodologies
- Advanced Battery Technologies Research
- Advanced Surface Polishing Techniques
- Bone Tissue Engineering Materials
- Graphene and Nanomaterials Applications
- Organic Electronics and Photovoltaics
- Interactive and Immersive Displays
- Nanomaterials and Printing Technologies
Stanford University
2015-2022
Soongsil University
2016-2020
Government of the Republic of Korea
2018
Seoul National University
2012-2015
Kim Il-sung University
2014
Some animals, such as the chameleon and cephalopod, have remarkable capability to change their skin colour. This unique characteristic has long inspired scientists develop materials devices mimic a function. However, it requires complex integration of stretchability, colour-changing tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic (e-skin), in which e-skin colour can easily be controlled through varying applied pressure along with duration. As...
Sensing the force digitally Our skin provides us with a flexible waterproof barrier, but it also contains sensor array that feels world around us. This feedback and helps to avoid hot object or increase strength of our grip on an may be slipping away. Tee et al. describe approach simulate mechanoreceptors human skin, using pressure-sensitive foils printed ring oscillators (see Perspective by Anikeeva Koppes). The successfully converted pressure into digital response in range comparable found...
Carbon capture and sequestration from point sources is an important component in the CO2 emission mitigation portfolio. In particular, sorbents with both high capacity selectivity are required for reducing cost of carbon capture. Although physisorbents have advantage low energy consumption regeneration, it remains a challenge to obtain sufficient CO2/N2 at same time. Here, we report controlled synthesis novel N-doped hierarchical that exhibits record-high Henry's law among physisorptive...
Two-dimensional materials, such as graphene, are attractive for both conventional semiconductor applications and nascent in flexible electronics. However, the high tensile strength of graphene results fracturing at low strain, making it challenging to take advantage its extraordinary electronic properties stretchable To enable excellent strain-dependent performance transparent conductors, we created nanoscrolls between stacked layers, referred multilayer graphene/graphene scrolls (MGGs)....
Multiscale, hierarchically patterned surfaces, such as lotus leaves, butterfly wings, adhesion pads of gecko lizards are abundantly found in nature, where microstructures usually used to strengthen the mechanical stability while nanostructures offer main functionality, i.e., wettability, structural color, or dry adhesion. To emulate hierarchical structures multiscale, multilevel patterning has been extensively utilized for last few decades towards various applications ranging from wetting...
Abstract Photonic skins enable a direct and intuitive visualization of various physical mechanical stimuli with eye‐readable colorations by intimately laminating to target substrates. Their development is still at infancy compared that electronic skins. Here, an ultra‐adaptable, large‐area (10 × 10 cm 2 ), multipixel (14 14) photonic skin based on naturally abundant sustainable biopolymer shape‐memory, responsive multiphase cellulose derivative presented. The wearable, mainly consists sensor...
A microneedle patch that uses snake fang–inspired multiple open grooves can rapidly deliver liquid-phase drugs and vaccines under capillary action.
Abstract The manipulation of droplets is used in a wide range applications, from lab-on-a-chip devices to bioinspired functional surfaces. Although variety droplet techniques have been proposed, active, fast and reversible pure discrete remains elusive due the technical limitations previous techniques. Here, we describe novel technique that enables fast, precise control over position motion with only permanent magnet by utilizing magnetically responsive flexible film possessing actuating...
Hemispherical image sensors simplify lens designs, reduce optical aberrations, and improve resolution for compact wide-field-of-view cameras. To achieve hemispherical sensors, organic materials are promising candidates due to the following advantages: tunability of optoelectronic/spectral response low-temperature low-cost processes. Here, a photolithographic process is developed prepare sensor array using thin film photomemory transistors with density 308 pixels per square centimeter. This...
Due to the lack of a bandgap, applications graphene require special device structures and engineering strategies enable semiconducting characteristics at room temperature. To this end, graphene-based vertical field-effect transistors (VFETs) are emerging as one most promising candidates. Previous work attributed current modulation primarily gate-modulated graphene-semiconductor Schottky barrier. Here, we report first experimental evidence that partially screened field effect selective...
A simple yet scalable strategy for fabricating dry adhesives with mushroom-shaped micropillars is achieved by a combination of the roll-to-roll process and modulated UV-curable elastic poly(urethane acrylate) (e-PUA) resin. The e-PUA combines major benefits commercial PUA poly(dimethylsiloxane) (PDMS). It not only can be cured within few seconds like but also possesses good mechanical properties comparable to those PDMS. roll-type fabrication system equipped rollable mold UV exposure unit...
Organic field-effect transistors have attracted much attention because of their potential use in low-cost, large-area, flexible electronics. High-performance organic require a low density grain boundaries films and decrease the charge trap at semiconductor–dielectric interface for efficient transport. In this respect, role dielectric material is crucial it primarily determines growth film interfacial density. Here, we demonstrate chemical vapor-deposited hexagonal boron nitride (CVD h-BN) as...
Abstract Flexible, transparent, conductive electrodes are key elements of emerging flexible electronic and energy devices. Such should form an intimate physical contact with various active components devices to ensure stable, low‐resistant electrical contacts. However, formation techniques based largely on conventional soldering, pastes, mechanical clamping, thin film deposition. These generally result in damaged, contaminated, bulky, uncontrollable interfaces. A self‐attachable, flexible,...
We present a simple method for fabricating robust dry adhesives by coating soft polydimethyl siloxane (PDMS) thin layer on rigid backbone micropillars of polyurethane acrylate (PUA). These core–shell type demonstrated enhanced durability both in normal and shear adhesion over more than 100 cycles attachment detachment. Relatively strong (∼11.4 N cm−2) (∼15.3 forces were observed, which similar to or even larger those homogeneous PDMS micropillars. A theoretical model based beam deflection...
Abstract Topographic features play a crucial role in the regulation of physiologically relevant cell and tissue functions. Here, an analysis feature‐size‐dependent cell–nanoarchitecture interactions is reported using array scaffolds form uniformly spaced ridge/groove structures for engineering wound healing. The ridge groove widths nanopatterns are varied from 300 to 800 nm nanotopography classified into three size ranges: dense (300–400 nm), intermediate (500–600 sparse (700–800 nm). On...
Inspired by the exceptional climbing ability of gecko lizards, artificial fibrillar adhesives have been extensively studied over last decade both experimentally and theoretically. Therefore, a new leap towards practical uses beyond academic horizon is timely highly anticipated. To this end, we present adhesive in form bridged micropillars its application to transportation system with detachment mechanism inspired behaviour lizards. The shows strong normal attachment (∼30 N cm−2) as well easy...
Abstract The design of water collectors that capture atmospheric fogs has been challenging due to the reliability issue. In particular, small openings collecting surfaces are often clogged by large‐size droplets. additional hydraulic resistances added prevent fog pathways and further lower overall performance coefficients decreasing shade coefficient collectors. clogging issues can be addressed modulating harvesters' surface chemistry structures deliver droplets efficiently re‐entrainment...