• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.95-96
• /
• 2012

• ETRI Journal
• /
• v.40 no.2
• /
• pp.275-282
• /
• 2018

Flash reduction of graphene oxide is an efficient method for producing high quality reduced graphene oxide under room temperature ambient conditions without the use of hazardous reducing agents (such as hydrazine and hydrogen iodide). The entire process is fast, low-cost, and suitable for large-scale fabrication, which makes it an attractive process for industrial manufacturing. Herein, we present a simple fabrication method for a flexible in-plane graphene micro-supercapacitor using flash light irradiation. All carbon-based, monolithic supercapacitors with in-plane geometry can be fabricated with simple flash irradiation, which occurs in only a few milliseconds. The thinness of the fabricated device makes it highly flexible and thus useful for a variety of applications, including portable and wearable electronics. The rapid flash reduction process creates a porous graphene structure with high surface area and good electrical conductivity, which ultimately results in high specific capacitance ($36.90mF\;cm^{-2}$) and good cyclic stability up to 8,000 cycles.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.31 no.4
• /
• pp.379-384
• /
• 1995

The retinomotor responses of jack mackerel, Trachurus japonicus and carp, Cyprinus carpio were studied for the different strobe flash frequencies in respects of the application of the light stimulus to herding and barrier system. The strobe flash frequencies ranged at 1.7, 5, 10, 25, 430Hz in jack mackerel and 1.7, 5, 25Hz in carp. The retinal adaptation ratio was examined histologically according to the time elasped of 1, 5, 10, 30min after turning on the light in each experimental condition. Cone index were determined in order to express the retinal adaptation ratio. Jack mackerel showed an increase of the retinal adaptation ratio ranging from average 27% at the pre-stimulus light to 42.6%, 49.8%, 59.8% and 83.1% at the irradiation times of 1, 5, 10 and 30min., respectively. Carp showed an increase of the retinal adaptation ratio ranging from average 28.4% at the pre-stimulus light to 51%, 53.9% and 91.3% at the irradiation times of 1, 5 and 30min., respectively. The light adaptation process was observed to be fast approximately in order of 430Hz, 25Hz, 5Hz, 1.7Hz and 10Hz for jack mackerel, and 25Hz, 5Hz and 1.7Hz for carp, and to be light-adaptated in 30 minutes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.4
• /
• pp.427-432
• /
• 2024

The polymer crystallization process, promoting the formation of ferroelectric β-phase, is essential for developing polyvinylidene fluoride (PVDF)-based high-performance piezoelectric energy harvesters. However, traditional high-temperature annealing is unsuitable for the manufacture of flexible piezoelectric devices due to the thermal damage to plastic components that occurs during the long processing times. In this study, we investigated the feasibility of introducing a flash lamp annealing that can rapidly induce the β-phase in the PVDF layer while avoiding device damage through selective heating. The flash light-irradiated PVDF films achieved a maximum β-phase content of 76.52% under an applied voltage of 300 V and an on-time of 1.5 ms, a higher fraction than that obtained through thermal annealing. The PVDF-based piezoelectric energy harvester with the optimized irradiation condition generates a stable output voltage of 0.23 V and a current of 102 nA under repeated bendings. These results demonstrate that flash lamp annealing can be an effective process for realizing the mass production of PVDF-based flexible electronics.