Manual, In situ, Real-Time Nanofabrication using Cracking through Indentation

Nam, Koo Hyun; Suh, Yong-Suk; Yeo, Junyeob; Woo, Deok Ha

doi:10.1038/srep18892

Cited by 10 publications

(11 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As propagating cracks typically continue to a free boundary, strategies to arrest cracks (i.e., crack stop or crack termination) are critical to the utility of this patterning approach. In prior work on crack-assisted fabrication, crack termination is normally achieved by patterning structures on the substrate before cracking, such as stair-profiled structures [32,53] or notch-tonotch termination sites. [30,31] These methods require additional multistep lithography processes for structural modification of the substrates.…”

Section: Resultsmentioning

confidence: 99%

From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates

et al. 2021

View full text Add to dashboard Cite

The cost, form, and performance of the device are limited by the conditions necessary for these processing techniques. For example, conventional photolithography typically requires patterned light to generate user-defined microscale patterns. [3][4][5] More sophisticated techniques such as electron-beam lithography or dip-pen lithography can pattern nanoscale features, but these multistep scanning processes are highcost and labor-intensive. [6,7] Thus, fabrication techniques that can produce highly organized patterns or structures at small size scales with a simple process may offer significant advantages.In synthetic systems, cracking is normally an unwelcomed, uncontrollable, and chaotic phenomenon caused by mechanical conditions that induce material failure. However, living systems, such as the skin of crocodiles and elephants, often show examples of self-organized crack patterns caused by intrinsic anisotropy. [8,9] Inspired by nature, recent advances in crack-assisted fabrication techniques, also referred to as cracklithography, have demonstrated how the humble crack can be Cracks are typically associated with the failure of materials. However, cracks can also be used to create periodic patterns on the surfaces of materials, as observed in the skin of crocodiles and elephants. In synthetic materials, surface patterns are critical to micro-and nanoscale fabrication processes. Here, a strategy is presented that enables freely programmable patterns of cracks on the surface of a polymer and then uses these cracks to pattern other materials. Cracks form during deposition of a thin film metal on a liquid crystal polymer network (LCN) and follow the spatially patterned molecular order of the polymer. These patterned sub-micrometer scale cracks have an order parameter of 0.98 ± 0.02 and form readily over centimeter-scale areas on the flexible substrates. The patterning of the LCN enables cracks that turn corners, spiral azimuthally, or radiate from a point. Conductive inks can be filled into these oriented cracks, resulting in flexible, anisotropic, and transparent conductors. This materials-based processing approach to patterning cracks enables unprecedented control of the orientation, length, width, and depth of the cracks without costly lithography methods. This approach promises new architectures of electronics, sensors, fluidics, optics, and other devices with micro-and nanoscale features.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202008434. IntroductionProcesses that allow patterning of materials at the micro-or nanoscale enable many devices, including active electronics,

show abstract

Section: Resultsmentioning

confidence: 99%

From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Nam et al 304 proposed a 1D patterning technology for nanofabrication purposes. In this technique, controlled propagation of a crack initiated with a simple manually generated indentation creates the channels.…”

Section: Fabricationmentioning

confidence: 99%

Section: Fabricationmentioning

confidence: 99%

Transport Phenomena in Nano/Molecular Confinements

et al. 2020

View full text Add to dashboard Cite

The transport of fluid and ions in nano/ molecular confinements is the governing physics of a myriad of embodiments in nature and technology including human physiology, plants, energy modules, water collection and treatment systems, chemical processes, materials synthesis, and medicine. At nano/molecular scales, the confinement dimension approaches the molecular size and the transport characteristics deviates significantly from that at macro/micro scales. A thorough understanding of physics of transport at these scales and associated fluid properties is undoubtedly critical for future technologies. This compressive review provides an elaborate picture on the promising future applications of nano/molecular transport, highlights experimental and simulation metrologies to probe and comprehend this transport phenomenon, discusses the physics of fluid transport, tunable flow by orders of magnitude, and gating mechanisms at these scales, and lists the advancement in the fabrication methodologies to turn these transport concepts into reality. Properties such as chain-like liquid transport, confined gas transport, surface charge-driven ion transport, physical/chemical ion gates, and ion diodes will provide avenues to devise technologies with enhanced performance inaccessible through macro/micro systems. This review aims to provide a consolidated body of knowledge to accelerate innovation and breakthrough in the above fields.

show abstract

“…18 Softlithography-like replica molding typically results in buckling, pairing, or collapse of HAR nanostructures. 19 Patterning HAR structures based on dissolving templates 20 or controllable cracking 21 is not scalable or limited in terms of geometric design. Nanoimprint lithography (NIL) has emerged as a powerful nanofabrication technique for a broad range of applications in electronics, photonics, microfluidics, and biomedicine.…”

Section: Introductionmentioning

confidence: 99%

Facile Nanoimprinting of Robust High-Aspect-Ratio Nanostructures for Human Cell Biomechanics

Shafagh

Shen

Youhanna

et al. 2020

ACS Appl. Bio Mater.

View full text Add to dashboard Cite

High-aspect-ratio and hierarchically nanostructured surfaces are common in nature. Synthetic variants are of interest for their specific chemical, mechanic, electric, photonic, or biologic properties but are cumbersome in fabrication or suffer from structural collapse. Here, we replicated and directly biofunctionalized robust, large-area, and high-aspect-ratio nanostructures by nanoimprint lithography of an off-stoichiometric thiol–ene-epoxy polymer. We structuredin a single-step processdense arrays of pillars with a diameter as low as 100 nm and an aspect ratio of 7.2; holes with a diameter of 70 nm and an aspect ratio of >20; and complex hierarchically layered structures, all with minimal collapse and defectivity. We show that the nanopillar arrays alter mechanosensing of human hepatic cells and provide precise spatial control of cell attachment. We speculate that our results can enable the widespread use of high-aspect-ratio nanotopograhy applications in mechanics, optics, and biomedicine.

show abstract

Manual, In situ, Real-Time Nanofabrication using Cracking through Indentation

Cited by 10 publications

References 38 publications

From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates

From Chaos to Control: Programmable Crack Patterning with Molecular Order in Polymer Substrates

Transport Phenomena in Nano/Molecular Confinements

Facile Nanoimprinting of Robust High-Aspect-Ratio Nanostructures for Human Cell Biomechanics

Contact Info

Product

Resources

About