Diponegoro University students develop a device that is able to convert noise into electrical energy. They named the device ‘Crazy’ or Sound Energy Harvesting. the three Undip students included Rifki Rokhanudin, Ragil Adi Nugroho from Undip Physics Study Program, and Yudha Cindy Pratama from Undip Electrical Engineering Study Program. They succeeded in developing a tool to convert the noise at the airport into environmentally friendly electrical energy. To the Central Java Tribune, one of the members of Sinting developer, Ragil Adi Nugroho said, he and his friends had the idea since March 2019. The idea came when they visited the Ahmad Yani international airport in Semarang. “There we found the fact that the airport is noisy,” he said, Monday (7/22/2019). “We made a research idea to eliminate noise at the airport because the intensity is high and tends to be disturbing,” continued Ragil. From research conducted from March to July 2019, Ragil explained that they are trying to make a tool that can reflect noise. Sound energy through noise must then be converted into electrical energy. “Then from my try there is an idea to be converted into electrical energy,” said Ragil. According to Ragil, the concept of this crazy tool uses the working principle of electromagnetic induction. This means that this tool works according to the principles in the microphone.