• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.266.1-266.1
• /
• 2013

Large-scale single-crystal organic nanowire arrays were generated using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with two- or three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.632-632
• /
• 2013

We generated single-crystal organic nanowire arrays using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. The position of the nanowires on complex structures is easy to adjust, because the mold is movable on the substrates before the polar liquid layer, which acts as an adhesive lubricant, is dried. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with twoor three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.

• Journal of Neurogastroenterology and Motility
• /
• v.24 no.4
• /
• pp.570-576
• /
• 2018

Background/Aims Swallows with viscous or solid boluses in different body positions alter esophageal manometry patterns. Limitations of previous studies include lack of standardized viscous substrates and the need for chewing prior to swallowing solid boluses. We hypothesize that high-resolution impedance manometry (HRiM) using standardized viscous and super-viscous swallows in supine and upright positions improves sensitivity for detecting esophageal motility abnormalities when compared with traditional saline swallows. To establish normative values for these novel substrates, we recruited healthy volunteers and performed HRiM. Methods Standardized viscous and super-viscous substrates were prepared using "Thick-It" food thickener and a rotational viscometer. All swallows were administered in 5-mL increments in both supine and upright positions. HRiM metrics and impedance (bolus transit) were calculated. We used a paired two-tailed t test to compare all metrics by position and substrate. Results The 5-g, 7-g, and 10-g substrates measured 5000, 36 200, and 64 $700mPa{\cdot}sec$, respectively. In 18 volunteers, we observed that the integrated relaxation pressure was lower when upright than when supine for all substrates (P < 0.01). The 10-g substrate significantly increased integrated relaxation pressure when compared to saline in the supine position (P < 0.01). Substrates and positions also affected distal contractile integral, distal latency, and impedance values. Conclusions We examined HRiM values using novel standardized viscous and super-viscous substrates in healthy subjects for both supine and upright positions. We found that viscosity and position affected HRiM Chicago metrics and have potential to increase the sensitivity of esophageal manometry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.29-29
• /
• 2008

Realization of electronics with performance equal to established technologies that use rigid semiconductor wafers, but in lightweight, foldable and stretchable formats would enable many new application possibilities. Examples include wearable systems for personal health monitoring, 'smart' surgical gloves with integrated electronics and electronic eye type imagers that incorporate focal plane arrays on hemispherical substrates. Circuits that use organic or certain classes of inorganic electronic materials on plastic or steel foil substrates can provide some degree of mechanical flexibility, but they cannot be folded or stretched. Also, with few exceptions such systems offer only modest electrical performance. In this talk, I will present a new approach to high performance, flexible and stretchable integrated circuits. These systems combine single-crystal silicon nanoribbons with thin plastic or elastomeric substrates using both "top-down" and "transfer-printing" technologies. The strategies represent promising routes to high performance, flexible and stretchable optoelectronic devices that can incorporate established, high performance inorganic electronic materials.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.75-75
• /
• 2015

Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2009.08a
• /
• pp.296-296
• /
• 2009

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1340-1343
• /
• 2007

We have simultaneously fabricated LTPS TFTs and integrated photodiodes on the same glass substrates without any additional LTPS process. The structure of an integrated photodiode is a lateral p-i-n diode with a gate. The performances of a photodiode were improved at a negative gate voltage.

• Korean Journal of Optics and Photonics
• /
• v.13 no.3
• /
• pp.209-214
• /
• 2002

The effect of surface roughness on mirror scattering has been studied. Five kinds of substrates with different surface roughness were fabricated. On those substrates, a dielectric multi-layer coating with high reflectivity was deposited by ion beam sputtering and electron beam evaporation. A total integrated scattering measurement set-up was built for the evaluation of deposited samples. Most of the ion beam sputtered mirrors showed lower scattering than the electron beam evaporated one, which deposited on substrates similar in surface roughness. Over ~2 $\AA$ in surface roughness, scattering strongly depend on the micro-structure of the super-polished surface. The lowest scattering we have achieved is 2.06 ppm by ion beam sputtering from the substrate with surface roughness of 0.23 $\AA$.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.534-536
• /
• 2009

We have fabricated solution-processed zinc-tin oxide thin film transistors (TFTs) and simple circuits on glass substrates. We report a solutionprocessed zinc-tin oxide TFTs on silicon wafer with mobility greater than 9 $cm^2/V{\cdot}s$ (W/L = 100/5 ${\mu}m$) and threshold voltage variation of less than 1 V after bias-stressing. Also, we fabricated solution-processed zinc-tin oxide circuits including inverters and 7-stage ring oscillators fabricated on glass substrates using the developed zinc-tin oxide TFTs.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.411-411
• /
• 2012

Over the recent years, surface enhanced Raman spectroscopy (SERS) has dramatically grown as a label-free detecting technique with the high level of selectivity and sensitivity. Conventional SERS-active nanostructured layers have been deposited or patterned on rigid substrates such as silicon wafers and glass slides. Such devices fabricated on a flexible platform may offer additional functionalities and potential applications. For example, flexible SERS-active substrates can be integrated into microfluidic diagnostic devices with round-shaped micro-channel, which has large surface area compared to the area of flat SERS-active substrates so that we may anticipate high sensitivity in a conformable device form. We demonstrate fabrication of flexible SERS-active nanostructured substrates based on soft-lithography for simple, low-cost processing. The SERS-active nanostructured substrates are fabricated using conventional Si fabrication process and inkjet printing methods. A Si mold is patterned by photolithography with an average height of 700 nm and an average pitch of 200 nm. Polydimethylsiloxane (PDMS), a mixture of Sylgard 184 elastomer and curing agnet (wt/wt = 10:1), is poured onto the mold that is coated with trichlorosilane for separating the PDMS easily from the mold. Then, the nano-pattern is transferred to the thin PDMS substrates. The soft lithographic methods enable the SERS-active nanostructured substrates to be repeatedly replicated. Silver layer is physically deposited on the PDMS. Then, gold nanoparticle (AuNP) inks are applied on the nanostructured PDMS using inkjet printer (Dimatix DMP 2831) to deposit AuNPs on the substrates. The characteristics of SERS-active substrates are measured; topology is provided by atomic force microscope (AFM, Park Systems XE-100) and Raman spectra are collected by Raman spectroscopy (Horiba LabRAM ARAMIS Spectrometer). We anticipate that the results may open up various possibilities of applying flexible platform to highly sensitive Raman detection.