The speaker works by rapidly heating and cooling air, and because it doesn’t require a box to create vibrations, it can exist as a flat or even curved surface. Researchers from the Korea Advanced Institute of Science and Technology (KAIST) developed a two-step (freeze-drying and reduction/doping) technique for producing the graphene aerogel. An array of these aerogels was then aligned in a 4x4 configuration to form a 40W speaker. The work, which was supported by the Samsung Research Funding Center for Future Technology and the National Research Foundation of Korea, is described in the journal ACS Applied Materials & Interfaces.
Poll: Should the UK’s railways be renationalised?
Rail passenger numbers declined from 1.27 million in 1946 to 735,000 in 1994 a fall of 42% over 49 years. In 2019 the last pre-Covid year the number...