Seung Hoon Han

Here we report on the synthesis of a graphene/polyaniline (PANI) nanocomposite and its application in the development of a hydrogen (H 2 ) gas sensor. Using a chemical synthetic route, graphene was prepared and ultrasonicated with a mixture of aniline monomer and ammonium persulfate to form PANI on its surface. The developed material was characterized by scanning electron microscopy (SEM), transmission electron microscopy, Raman spectroscopy, and X-ray photoemission spectroscopy. The SEM study r

We fabricated a high-performance pentacene organic thin-film transistor (OTFT) on plastic and passivated it with polyvinylalcohol and photosensitive acryl layers. The pentacene was grown on the thin-film transistor area using a self-organized process. The OTFT after the passivation exhibited the field-effect mobility of 0.80cm2∕Vs, threshold voltage of −9.2V, and on/off current ratio of 108. The field-effect mobility and threshold voltage change exponentially with time in air. The lifetime, defi

The authors studied the fabrication of a ring oscillator consisting of organic inverters showing no hysteresis in output characteristics. They designed and fabricated the ring oscillator with bootstrapping inverters made of pentacene organic thin-film transistors on plastic produced by self-organized process, exhibiting the field-effect mobility of ∼0.6cm2∕Vs, on/off current ratio of 107, and threshold voltage of −5V. The oscillation frequency of 3kHz and signal propagation delay of 15μs per sta

We studied the passivation of pentacene organic thin-film transistors (OTFTs) on plastic using four kinds of organic layers: photopatternable acryl (PA), polyvinylalcohol (PVA)/dichromated polyvinylalcohol (D-PVA), PVA/D-PVA/PA, and parylene-C. The initial mobility of the OTFTs was and the on/off current ratio was . The drop in the on-current and the increase in the off-currents were significant when PA was used as a passivation layer because of the damage to the pentacene active layer by the or

Abstract A high resolution (2 inch, 80 dpi) organic thin‐film transistor driven light‐emitting diode has been developed on plastic substrate. The pentacene OTFT array was fabricated using self‐organized process. The TFT in the array exhibited an average field‐effect mobility of ∼1 cm 2 /Vs, an on/off current ratio of 10 7 , and a threshold voltage of ∼ −8 V after the bank formation with parylene‐C / SiN x , which is good enough to drive OLEDs. An AMOLED was driven in the bent state of 100 mm rad

BACKGROUND & OBJECTIVE: Oral stage dysphagia mostly caused by frontal lobe lesions. We investigated the relationship between oral hesitation and cognitive impairment after frontal lobe stroke. METHODS: We consecutively collected 946 patients with stroke from January 2016 to December 2020. Among them, 38 patients had only frontal lobe lesions. Video fluoroscopic swallowing study (VFSS) was performed in 5 stages from water to solid food. Patients who progressed to solid food are very rare, so we f

Abstract— A high‐performance bottom‐contact organic‐thin‐film transistor (OTFT) array on plastic using a self‐organized process has been developed. The effect of octadecyltrichlorosilane (OTS) treatment on the poly‐4‐vinylphenol (PVP) gate insulator on the performance of OTFT on plastic has been studied. The OTFT without OTS exhibited a field‐effect mobility of 0.1‐cm 2 /V‐sec on/off current ratio of >10 7 . On the other hand, the OTFT with OTS treatment exhibited a field‐effect mobility of 1

Abstract In this work, we fabricated inkjet printed OTFT with CNT source‐drain electrode for plastic displays. 6,13‐bis(pentylphenylethynyl)pentacene was used for printable organic semiconductor. The OTFT with CNT electrode exhibited the field‐effect mobility of 0.15 cm 2 /Vs, threshold voltage of −3.4 V with on‐off current ratio of ∼10 7 . The performance is suitable for driving e‐paper display on plastic. Especially normalized contact resistance was 10 times lower than that of bottom‐contact p

RATIONALE: Botulinum toxin A (BTX-A) injection is effective in treating focal dystonia. However, there are no prior reports regarding the treatment of progressive focal dystonia by a single BTX-A injection that affect a distant muscle. PATIENT CONCERNS: A 19-year-old male was referred to the rehabilitation clinic with a complaint of involuntary movement in his left big toe. The involuntary movement pattern was initially observed in the abduction direction only; however, it progressed to irregula

The purpose of this study is to suggest a kinetic faade and their controlling system towards Hanok. For this study, Hanok's degree of integrative comfort was analyzed and environment assessment system of Hanok comfort was utilized. Using the assessment system, the controlling system of kinetic faade was proposed and verified its applicability. As a result, it is turned that the proposed system would have a pretty good applicability to the relevant practical field.