Prototype and characteristic measurement of led-lit pet bottle handmade lantern with baby milk dropped into water

  • 1 Hiroshima Prefectural Hiroshima Minami High School, Hiroshima, Japan
  • 2 Hiroshima International University, Kure, Japan
  • 3 TED Ltd. Tokyo, Japan
  • 4 Hiroshima Institute of Technology, Hiroshima, Japan
  • 5 Institute of Electronics, Bulgarian Academy of Sciences, Sofia, Bulgaria


In recent years, natural disasters have frequently occurred in Japan, almost yearly, causing enormous damage. In Hiroshima Prefecture, heavy rains in August 2014 and July 2018 caused large-scale landslides. Power outages continued in the affected areas, and some survivors had been lighting campfires outdoors and using candles indoors. In times of disaster in which bad weather persists, it is difficult to safely secure lighting, which can adversely affect health. Lanterns can be created by putting a few drops of milk into a PET bottle filled with water and shining light from the bottle’s bottom. In this study, we used a light emitting diode (LED) as a light source to evaluate the luminance of handmade lanterns. Results suggested that when using tap water with one LED lamp and a 500 ml PET bottle, 1–2 drops of milk are suitable to achieve the optimal light scattering effect.



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