Abstract
A high power LED light and a charge pump with a LED indicator fixed with epoxy resin were developed in order to demonstrate reducing the cost of the deep-sea instruments. The LED light was brought at ca. 9200 m depth for five times. The light had no deformation and no crackes, and it worked after the deployents. It was also used to record the bottom at Tonga trench, where the world second deepest site (10800 m), and the video recording was succeeded. The charge pump was applied to confirm the electricity generation at the artificial hydrothermal vent in Iheya North hydrothermal field (1053 m). To protect electrolytic capacitors from pressure, they insulated from the resin with medicine capsules before fixing. The LED indicator was lighted on when the electrode of the fuel cell battery was inserted into the hydrothermal water. However, the degradation process of the epoxy resin under the deep-sea environments attributing high pressure and low temperature environments is still unknown. The guaranteed time of the instruments constructed with epoxy resin should be investigated throughout long term in situ exposure and the strength tests.
